diff --git a/AlgebraicDataflowArchitectureModel/models/Accounts.model b/AlgebraicDataflowArchitectureModel/models/Accounts.model
new file mode 100644
index 0000000..81093de
--- /dev/null
+++ b/AlgebraicDataflowArchitectureModel/models/Accounts.model
@@ -0,0 +1,7 @@
+channel CIO1 {
+	out accounts(l:List, signup(name:Str)) == cons(name, l)
+}
+
+channel CIO2(uid:Int) {
+	out accounts.{uid}(n:Str, changeName(name)) == name
+}
diff --git a/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java b/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
index 5832f46..d59f7dc 100644
--- a/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
+++ b/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
@@ -84,6 +84,8 @@
 	protected String curFileName = null;
 	protected String curFilePath = null;
 	protected ArrayList<CompilationUnit> codes = null;
+	
+	private boolean bReflectingArchitectureModel = false;
 
 	public Editor(mxGraphComponent graphComponent) {
 		this.graphComponent = graphComponent;
@@ -333,6 +335,7 @@
 	 * @return constructed mxGraph
 	 */
 	public mxGraph constructGraph(DataTransferModel model) {
+		bReflectingArchitectureModel = true;
 		((mxGraphModel) graph.getModel()).clear();
 		Object parent = graph.getDefaultParent();
 		graph.getModel().beginUpdate();
@@ -406,7 +409,8 @@
 			graph.getModel().endUpdate();
 		}
 		setTreeLayout();
-
+		
+		bReflectingArchitectureModel = false;
 		return graph;
 	}
 
@@ -574,6 +578,7 @@
 	}
 
 	public boolean connectEdge(mxCell edge, mxCell src, mxCell dst) {
+		if (bReflectingArchitectureModel) return false;
 		DataTransferModel model = getModel();
 		Channel srcCh = model.getChannel((String) src.getValue());
 		if (srcCh == null) {
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
index d4f5547..58d4365 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
@@ -27,6 +27,7 @@
 import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.DataConstraintModel;
 import models.dataConstraintModel.ResourcePath;
+import models.dataConstraintModel.Selector;
 import models.dataFlowModel.DataTransferModel;
 import models.dataFlowModel.DataTransferChannel;
 import models.dataFlowModel.DataTransferChannel.IResourceStateAccessor;
@@ -73,135 +74,160 @@
 		MethodDeclaration mainConstructor = new MethodDeclaration(mainTypeName, true);
 		mainType.addMethod(mainConstructor);
 		
-		// For each resource.
+		// For each resource path.
 		for (ResourceNode rn: resources) {
 			boolean f = false;
 			String resourceName = rn.getResource().getResourceName().substring(0, 1).toUpperCase()
 					+ rn.getResource().getResourceName().substring(1);
-			TypeDeclaration type = new TypeDeclaration(resourceName);
-			
-			// Declare the field to refer to each resource in the main type.
-			String fieldInitializer = "new " + resourceName + "(";
-			Set<ResourcePath> depends = new HashSet<>();
-			for (Edge e : rn.getOutEdges()) {
-				DataFlowEdge re = (DataFlowEdge) e;
-				ResourcePath dstRes = ((ResourceNode) re.getDestination()).getResource();
-				String resName = dstRes.getResourceName().substring(0, 1).toUpperCase() + dstRes.getResourceName().substring(1);
-				if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
-					depends.add(dstRes);
-					fieldInitializer += resName.toLowerCase() + ",";
-					f = true;
-				}
-			}
-			for (Edge e : rn.getInEdges()) {
-				DataFlowEdge re = (DataFlowEdge) e;
-				ResourcePath srcRes = ((ResourceNode) re.getSource()).getResource();
-				String resName = srcRes.getResourceName().substring(0, 1).toUpperCase() + srcRes.getResourceName().substring(1);
-				if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
-					depends.add(srcRes);
-					fieldInitializer += resName.toLowerCase() + ",";
-					f = true;
-				} else {
-					if (rn.getIndegree() > 1) {
-						// Declare a field to cash the state of the source resource in the type of the destination resource.
-						ResourcePath cashResId = ((ResourceNode) re.getSource()).getResource();
-						type.addField(new FieldDeclaration(
-								cashResId.getResourceStateType(), ((ResourceNode) re.getSource()).getResource().getResourceName(), getInitializer(cashResId)));
+			TypeDeclaration type = null;
+			for (CompilationUnit cu: codes) {
+				for (TypeDeclaration t: cu.types()) {
+					if (resourceName.equals(t.getTypeName())) {
+						type = t;
+						break;
 					}
 				}
+				if (type != null) break;
 			}
-			Set<ResourcePath> refs = new HashSet<>();
-			for (Channel cg : model.getChannels()) {
-				DataTransferChannel c = (DataTransferChannel) cg;
-				if (c.getInputResources().contains(rn.getResource())) {
-					for (ResourcePath id: c.getReferenceResources()) {
-						if (!refs.contains(id) && !depends.contains(id)) {
-							refs.add(id);
-							String refResName = id.getResourceName();
-							fieldInitializer += refResName.toLowerCase() + ",";
-							f = true;
+			if (type == null) {
+				// Add compilation unit for each resource.
+				type = new TypeDeclaration(resourceName);
+				CompilationUnit cu = new CompilationUnit(type);
+				cu.addImport(new ImportDeclaration("java.util.*"));
+				codes.add(cu);
+				
+				// Declare the field to refer to each resource in the main type.
+				String fieldInitializer = "new " + resourceName + "(";
+				Set<ResourcePath> depends = new HashSet<>();
+				for (Edge e : rn.getOutEdges()) {
+					DataFlowEdge re = (DataFlowEdge) e;
+					ResourcePath dstRes = ((ResourceNode) re.getDestination()).getResource();
+					String resName = dstRes.getResourceName().substring(0, 1).toUpperCase() + dstRes.getResourceName().substring(1);
+					if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
+						depends.add(dstRes);
+						fieldInitializer += resName.toLowerCase() + ",";
+						f = true;
+					}
+				}
+				for (Edge e : rn.getInEdges()) {
+					DataFlowEdge re = (DataFlowEdge) e;
+					ResourcePath srcRes = ((ResourceNode) re.getSource()).getResource();
+					String resName = srcRes.getResourceName().substring(0, 1).toUpperCase() + srcRes.getResourceName().substring(1);
+					if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
+						depends.add(srcRes);
+						fieldInitializer += resName.toLowerCase() + ",";
+						f = true;
+					} else {
+						if (rn.getIndegree() > 1) {
+							// Declare a field to cash the state of the source resource in the type of the destination resource.
+							ResourcePath cashResId = ((ResourceNode) re.getSource()).getResource();
+							type.addField(new FieldDeclaration(
+									cashResId.getResourceStateType(), ((ResourceNode) re.getSource()).getResource().getResourceName(), getInitializer(cashResId)));
 						}
 					}
 				}
-			}
-			if (f) fieldInitializer = fieldInitializer.substring(0, fieldInitializer.length() - 1);
-			fieldInitializer += ")";
-			FieldDeclaration field = new FieldDeclaration(new Type(resourceName, resourceName), rn.getResource().getResourceName());
-			mainType.addField(field);
-			Block manConstructorBody = mainConstructor.getBody();
-			if (manConstructorBody == null) {
-				manConstructorBody = new Block();
-				mainConstructor.setBody(manConstructorBody);
-			}
-			manConstructorBody.addStatement(rn.getResource().getResourceName() + " = " + fieldInitializer + ";");
-			
-			// Declare a constructor, fields and update methods in the type of each resource.
-			MethodDeclaration constructor = new MethodDeclaration(resourceName, true);
-			Block block = new Block();
-			depends = new HashSet<>();
-			for (Edge e : rn.getOutEdges()) {
-				DataFlowEdge re = (DataFlowEdge) e;
-				ResourcePath dstRes = ((ResourceNode) re.getDestination()).getResource();
-				String dstResName = dstRes.getResourceName().substring(0, 1).toUpperCase() + dstRes.getResourceName().substring(1);
-				if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
-					// Declare a field to refer to the destination resource of push transfer.
-					depends.add(dstRes);
-					type.addField(new FieldDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
-					constructor.addParameter(new VariableDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
-					block.addStatement("this." + dstResName.toLowerCase() + " = " + dstResName.toLowerCase() + ";");
-				}
-			}
-			for (Edge e : rn.getInEdges()) {
-				DataFlowEdge re = (DataFlowEdge) e;
-				ResourcePath srcRes = ((ResourceNode) re.getSource()).getResource();
-				String srcResName = srcRes.getResourceName().substring(0, 1).toUpperCase() + srcRes.getResourceName().substring(1);
-				if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
-					// Declare a field to refer to the source resource of pull transfer.
-					depends.add(srcRes);
-					type.addField(new FieldDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
-					constructor.addParameter(new VariableDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
-					block.addStatement("this." + srcResName.toLowerCase() + " = " + srcResName.toLowerCase() + ";");
-				} else {
-					// Declare an update method in the type of the destination resource.
-					ArrayList<VariableDeclaration> vars = new ArrayList<>();
-					vars.add(new VariableDeclaration(srcRes.getResourceStateType(), srcRes.getResourceName()));
-					DataTransferChannel c = (DataTransferChannel) re.getChannel();
-					for (ResourcePath ref: c.getReferenceResources()) {
-						if (!ref.equals(rn.getResource())) {
-							vars.add(new VariableDeclaration(ref.getResourceStateType(), ref.getResourceName()));
-						}
-					}
-					type.addMethod(new MethodDeclaration("update" + srcResName, false, typeVoid, vars));
-				}
-			}
-			// Declare a field to refer to the reference resource.
-			refs = new HashSet<>();
-			for (Channel cg : model.getChannels()) {
-				DataTransferChannel c = (DataTransferChannel) cg;
-				if (c.getInputResources().contains(rn.getResource())) {
-					for (ResourcePath id: c.getReferenceResources()) {
-						if (!refs.contains(id) && !depends.contains(id)) {
-							refs.add(id);
-							String refResName = id.getResourceName();
-							refResName = refResName.substring(0, 1).toUpperCase() + refResName.substring(1);
-							type.addField(new FieldDeclaration(new Type(refResName, refResName), id.getResourceName()));
-							constructor.addParameter(new VariableDeclaration(new Type(refResName, refResName), id.getResourceName()));						
-							block.addStatement("this." + id.getResourceName() + " = " + id.getResourceName() + ";");
+				Set<ResourcePath> refs = new HashSet<>();
+				for (Channel ch : model.getChannels()) {
+					DataTransferChannel c = (DataTransferChannel) ch;
+					if (c.getInputResources().contains(rn.getResource())) {
+						for (ResourcePath res: c.getReferenceResources()) {
+							if (!refs.contains(res) && !depends.contains(res)) {
+								refs.add(res);
+								String refResName = res.getResourceName();
+								fieldInitializer += refResName.toLowerCase() + ",";
+								f = true;
+							}
 						}
 					}
 				}
+				if (f) fieldInitializer = fieldInitializer.substring(0, fieldInitializer.length() - 1);
+				fieldInitializer += ")";
+				FieldDeclaration field = new FieldDeclaration(new Type(resourceName, resourceName), rn.getResource().getResourceName());
+				mainType.addField(field);
+				Block mainConstructorBody = mainConstructor.getBody();
+				if (mainConstructorBody == null) {
+					mainConstructorBody = new Block();
+					mainConstructor.setBody(mainConstructorBody);
+				}
+				mainConstructorBody.addStatement(rn.getResource().getResourceName() + " = " + fieldInitializer + ";");
+				
+				// Declare a constructor, fields and update methods in the type of each resource.
+				MethodDeclaration constructor = new MethodDeclaration(resourceName, true);
+				Block block = new Block();
+				depends = new HashSet<>();
+				for (Edge e : rn.getOutEdges()) {
+					DataFlowEdge re = (DataFlowEdge) e;
+					ResourcePath dstRes = ((ResourceNode) re.getDestination()).getResource();
+					String dstResName = dstRes.getResourceName().substring(0, 1).toUpperCase() + dstRes.getResourceName().substring(1);
+					if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
+						// Declare a field to refer to the destination resource of push transfer.
+						depends.add(dstRes);
+						type.addField(new FieldDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
+						constructor.addParameter(new VariableDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
+						block.addStatement("this." + dstResName.toLowerCase() + " = " + dstResName.toLowerCase() + ";");
+					}
+				}
+				for (Edge e : rn.getInEdges()) {
+					DataFlowEdge re = (DataFlowEdge) e;
+					ResourcePath srcRes = ((ResourceNode) re.getSource()).getResource();
+					String srcResName = srcRes.getResourceName().substring(0, 1).toUpperCase() + srcRes.getResourceName().substring(1);
+					if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
+						// Declare a field to refer to the source resource of pull transfer.
+						depends.add(srcRes);
+						type.addField(new FieldDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
+						constructor.addParameter(new VariableDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
+						block.addStatement("this." + srcResName.toLowerCase() + " = " + srcResName.toLowerCase() + ";");
+					} else {
+						// Declare an update method in the type of the destination resource.
+						ArrayList<VariableDeclaration> vars = new ArrayList<>();
+						vars.add(new VariableDeclaration(srcRes.getResourceStateType(), srcRes.getResourceName()));
+						DataTransferChannel c = (DataTransferChannel) re.getChannel();
+						for (ResourcePath ref: c.getReferenceResources()) {
+							if (!ref.equals(rn.getResource())) {
+								vars.add(new VariableDeclaration(ref.getResourceStateType(), ref.getResourceName()));
+							}
+						}
+						type.addMethod(new MethodDeclaration("update" + srcResName, false, typeVoid, vars));
+					}
+				}
+				// Declare a field to refer to the reference resource.
+				refs = new HashSet<>();
+				for (Channel ch : model.getChannels()) {
+					DataTransferChannel c = (DataTransferChannel) ch;
+					if (c.getInputResources().contains(rn.getResource())) {
+						for (ResourcePath res: c.getReferenceResources()) {
+							if (!refs.contains(res) && !depends.contains(res)) {
+								refs.add(res);
+								String refResName = res.getResourceName();
+								refResName = refResName.substring(0, 1).toUpperCase() + refResName.substring(1);
+								type.addField(new FieldDeclaration(new Type(refResName, refResName), res.getResourceName()));
+								constructor.addParameter(new VariableDeclaration(new Type(refResName, refResName), res.getResourceName()));						
+								block.addStatement("this." + res.getResourceName() + " = " + res.getResourceName() + ";");
+							}
+						}
+					}
+				}
+				constructor.setBody(block);
+				if (constructor.getParameters() != null)
+					type.addMethod(constructor);
 			}
-			constructor.setBody(block);
-			if (constructor.getParameters() != null)
-				type.addMethod(constructor);
 			
 			// Declare input methods in resources and the main type.
-			for (Channel cg : model.getIOChannels()) {
-				for (ChannelMember cm : ((DataTransferChannel) cg).getOutputChannelMembers()) {
+			Channel inCh = null;
+			for (Channel ch : model.getIOChannels()) {
+				for (ChannelMember cm : ((DataTransferChannel) ch).getOutputChannelMembers()) {
 					if (cm.getResource().equals(rn.getResource())) {
+						inCh = ch;
 						Expression message = cm.getStateTransition().getMessageExpression();
-						if (message.getClass() == Term.class) {
+						if (message instanceof Term) {
+							// In the resource.
 							ArrayList<VariableDeclaration> params = new ArrayList<>();
+							for (Selector selector: ch.getAllSelectors()) {
+								if (selector.getExpression() instanceof Variable) {
+									Variable var = (Variable) selector.getExpression();
+									params.add(new VariableDeclaration(var.getType(), var.getName()));								
+								}
+							}
 							for (Variable var: message.getVariables().values()) {
 								params.add(new VariableDeclaration(var.getType(), var.getName()));
 							}
@@ -209,8 +235,10 @@
 									((Term) cm.getStateTransition().getMessageExpression()).getSymbol().getImplName(),
 									false, typeVoid, params);
 							type.addMethod(input);
+							
+							// In the main type.
 							String str = ((Term) cm.getStateTransition().getMessageExpression()).getSymbol().getImplName();
-							input = getMethod(mainType, str);
+							input = getMethod(mainType, str, params);
 							if (input == null) {
 								input = new MethodDeclaration(str, false, typeVoid, params);
 								mainType.addMethod(input);
@@ -226,37 +254,101 @@
 									}
 								}
 							}
-						} else if (message.getClass() == Variable.class) {
-							MethodDeclaration input = new MethodDeclaration(
-									((Variable) cm.getStateTransition().getMessageExpression()).getName(),
-									false, typeVoid, null);
+						} else if (message instanceof Variable) {
+							// In the resource.
+							ArrayList<VariableDeclaration> params = new ArrayList<>();
+							for (Selector selector: ch.getAllSelectors()) {
+								if (selector.getExpression() instanceof Variable) {
+									Variable var = (Variable) selector.getExpression();
+									params.add(new VariableDeclaration(var.getType(), var.getName()));								
+								}
+							}
+							MethodDeclaration input = null;
+							if (params.size() > 0) {
+								input = new MethodDeclaration(
+										((Variable) cm.getStateTransition().getMessageExpression()).getName(),
+										false, typeVoid, params);
+							} else {
+								input = new MethodDeclaration(
+										((Variable) cm.getStateTransition().getMessageExpression()).getName(),
+										false, typeVoid, null);								
+							}
 							type.addMethod(input);
+							
+							// In the main type.
 							String str = ((Variable) cm.getStateTransition().getMessageExpression()).getName();
-							input = getMethod(mainType, str);
+							input = getMethod(mainType, str, params);
 							if (input == null) {
-								input = new MethodDeclaration(str, false, typeVoid, null);
+								if (params.size() > 0) {
+									input = new MethodDeclaration(str, false, typeVoid, params);
+								} else {
+									input = new MethodDeclaration(str, false, typeVoid, null);
+								}
 								mainType.addMethod(input);
 							}
 						}
 					}
 				}
-			}
+			}			
 			
 			// Declare the field to store the state in the type of each resource.
-			if (((StoreAttribute) rn.getAttribute()).isStored()) {
+			if (((StoreAttribute) rn.getAttribute()).isStored() && rn.getResource().getNumberOfParameters() == 0) {
 				ResourcePath resId = rn.getResource();
 				type.addField(new FieldDeclaration(resId.getResourceStateType(), "value", getInitializer(resId)));
 			}
 			
-			// Declare the getter method to obtain the state in the type of each resource.
-			type.addMethod(new MethodDeclaration("getValue",
-					rn.getResource().getResourceStateType()));
-			
-			// Add compilation unit for each resource.
-			CompilationUnit cu = new CompilationUnit(type);
-			cu.addImport(new ImportDeclaration("java.util.*"));
-			codes.add(cu);
+			// Declare the getter methods to obtain the state in the resource and the main type.
+			if (inCh == null) {
+				DataFlowEdge e = (DataFlowEdge) rn.getInEdges().iterator().next();
+				if (e != null) {
+					inCh = e.getChannel();
+				}
+			}
+			if (inCh != null) {
+				// In the resource.
+				ArrayList<VariableDeclaration> params = new ArrayList<>();
+				for (Selector selector: inCh.getAllSelectors()) {
+					if (selector.getExpression() instanceof Variable) {
+						Variable var = (Variable) selector.getExpression();
+						params.add(new VariableDeclaration(var.getType(), var.getName()));								
+					}
+				}
+				if (params.size() > 0) {
+					type.addMethod(new MethodDeclaration("getValue", false, rn.getResource().getResourceStateType(), params));
+				} else {
+					type.addMethod(new MethodDeclaration("getValue", rn.getResource().getResourceStateType()));					
+				}
+				
+				// In the main type.
+				MethodDeclaration getter = null;
+				if (params.size() > 0) {
+					getter = new MethodDeclaration("get" + rn.getResource().getResourceName().substring(0, 1).toUpperCase()
+															+ rn.getResource().getResourceName().substring(1),
+													false,
+													rn.getResource().getResourceStateType(),
+													params);
+				} else {
+					getter = new MethodDeclaration("get" + rn.getResource().getResourceName().substring(0, 1).toUpperCase()
+															+ rn.getResource().getResourceName().substring(1),
+													rn.getResource().getResourceStateType());
+				}
+				getter.setBody(new Block());
+				if (params.size() > 0) {
+					String sParams = "";
+					String delimiter = "";
+					for (VariableDeclaration var: params) {
+						sParams += delimiter + var.getName();
+						delimiter = ", ";
+					}
+					getter.getBody().addStatement("return " + rn.getResource().getResourceName() + ".getValue(" + sParams + ");");
+				} else {
+					getter.getBody().addStatement("return " + rn.getResource().getResourceName() + ".getValue();");
+				}
+				mainType.addMethod(getter);
+			}
 		}
+		
+		
 
 		// Declare the Pair class.
 		boolean isCreatedPair = false;
@@ -293,34 +385,20 @@
 			}
 		}
 		
-		// Declare getter methods in the main type.
-		for (Node n : graph.getNodes()) {
-			ResourceNode rn = (ResourceNode) n;
-			MethodDeclaration getter = new MethodDeclaration(
-					"get" + rn.getResource().getResourceName().substring(0, 1).toUpperCase()
-							+ rn.getResource().getResourceName().substring(1),
-					rn.getResource().getResourceStateType());
-			getter.setBody(new Block());
-			getter.getBody().addStatement(
-					"return " + rn.getResource().getResourceName() + ".getValue();");
-			mainType.addMethod(getter);
-		}
-		
-		
-		HashSet<String> tmps = new HashSet<>();
-		HashSet<String> cont = new HashSet<>();
-		for (MethodDeclaration method : mainType.getMethods()) {
-			if (!tmps.contains(method.getName()))
-				tmps.add(method.getName());
-			else
-				cont.add(method.getName());
-		}
-		for (MethodDeclaration method : mainType.getMethods()) {
-			if (cont.contains(method.getName())) {
-				method.setName(method.getName() + method.getParameters().get(0).getName().substring(0, 1).toUpperCase()
-						+ method.getParameters().get(0).getName().substring(1));
-			}
-		}
+//		HashSet<String> tmps = new HashSet<>();
+//		HashSet<String> cont = new HashSet<>();
+//		for (MethodDeclaration method : mainType.getMethods()) {
+//			if (!tmps.contains(method.getName()))
+//				tmps.add(method.getName());
+//			else
+//				cont.add(method.getName());
+//		}
+//		for (MethodDeclaration method : mainType.getMethods()) {
+//			if (cont.contains(method.getName())) {
+//				method.setName(method.getName() + method.getParameters().get(0).getName().substring(0, 1).toUpperCase()
+//						+ method.getParameters().get(0).getName().substring(1));
+//			}
+//		}
 		return codes;
 	}
 
@@ -423,9 +501,21 @@
 		orderedList.add(0, curNode);
 	}
 
-	private static MethodDeclaration getMethod(TypeDeclaration type, String methodName) {
+	private static MethodDeclaration getMethod(TypeDeclaration type, String methodName, List<VariableDeclaration> params) {
 		for (MethodDeclaration m: type.getMethods()) {
-			if (m.getName().equals(methodName)) return m;
+			if (m.getName().equals(methodName)) {
+				if (m.getParameters() == null && (params == null || params.size() == 0)) return m;
+				if (m.getParameters() != null && params != null && m.getParameters().size() == params.size()) {
+					boolean matchParams = true;
+					for (int i = 0; i < m.getParameters().size(); i++) {
+						if (!m.getParameters().get(i).getType().equals(params.get(i).getType())) {
+							matchParams = false;
+							break;
+						}
+					}
+					if (matchParams) return m;
+				}
+			}
 		}
 		return null;
 	}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
index 1e8aec5..9598f60 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
@@ -11,6 +11,7 @@
 import code.ast.CompilationUnit;
 import code.ast.MethodDeclaration;
 import code.ast.TypeDeclaration;
+import code.ast.VariableDeclaration;
 import models.Edge;
 import models.Node;
 import models.algebra.Expression;
@@ -25,6 +26,7 @@
 import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.DataConstraintModel;
 import models.dataConstraintModel.ResourcePath;
+import models.dataConstraintModel.Selector;
 import models.dataFlowModel.DataTransferModel;
 import models.dataFlowModel.DataTransferChannel;
 import models.dataFlowModel.DataTransferChannel.IResourceStateAccessor;
@@ -85,26 +87,28 @@
 									update.addFirstStatement(cashStatement);
 								}								
 							}
-							MethodDeclaration getter = getGetterMethod(dstType);
 							if (((StoreAttribute) dst.getAttribute()).isStored()) {
-								// returns the current state stored in a field.
-								if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-									Type resourceType = dst.getResource().getResourceStateType();
-									if (model.isPrimitiveType(resourceType)) {
-										getter.addStatement("return value;");
-									} else {
-										// copy the current state to be returned as a 'value'
-										String implTypeName = resourceType.getImplementationTypeName();
-//										String interfaceTypeName = resourceType.getInterfaceTypeName();
-//										String concreteTypeName;
-//										if (interfaceTypeName.contains("<")) {
-//											String typeName = implTypeName.substring(0, implTypeName.indexOf("<"));
-////											String generics = interfaceTypeName.substring(interfaceTypeName.indexOf("<") + 1, interfaceTypeName.lastIndexOf(">"));
-//											concreteTypeName = typeName + "<>";
-//										} else {
-//											concreteTypeName = implTypeName;
-//										}
-										getter.addStatement("return new " + implTypeName + "(value);");
+								if (dst.getResource().getNumberOfParameters() == 0) {
+									// returns the current state stored in a field.
+									MethodDeclaration getter = getGetterMethod(dstType, null);
+									if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+										Type resourceType = dst.getResource().getResourceStateType();
+										if (model.isPrimitiveType(resourceType)) {
+											getter.addStatement("return value;");
+										} else {
+											// copy the current state to be returned as a 'value'
+											String implTypeName = resourceType.getImplementationTypeName();
+//											String interfaceTypeName = resourceType.getInterfaceTypeName();
+//											String concreteTypeName;
+//											if (interfaceTypeName.contains("<")) {
+//												String typeName = implTypeName.substring(0, implTypeName.indexOf("<"));
+////												String generics = interfaceTypeName.substring(interfaceTypeName.indexOf("<") + 1, interfaceTypeName.lastIndexOf(">"));
+//												concreteTypeName = typeName + "<>";
+//											} else {
+//												concreteTypeName = implTypeName;
+//											}
+											getter.addStatement("return new " + implTypeName + "(value);");
+										}
 									}
 								}
 							}
@@ -161,33 +165,35 @@
 							}
 						} else {
 							// for pull (or push/pull) data transfer
-							MethodDeclaration getter = getGetterMethod(dstType);
-							if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-								boolean isContainedPush = false;
-								HashMap<ResourcePath, IResourceStateAccessor> inputResourceToStateAccessor = new HashMap<>();
-								for (Edge eIn: dst.getInEdges()) {
-									DataFlowEdge dIn = (DataFlowEdge) eIn;
-									if (((PushPullAttribute) dIn.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
-										isContainedPush = true;
-										inputResourceToStateAccessor.put(((ResourceNode) dIn.getSource()).getResource(), JavaCodeGenerator.pushAccessor);
-									} else {
-										inputResourceToStateAccessor.put(((ResourceNode) dIn.getSource()).getResource(), JavaCodeGenerator.pullAccessor);
+							if (dst.getResource().getNumberOfParameters() == 0) {
+								MethodDeclaration getter = getGetterMethod(dstType, null);
+								if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+									boolean isContainedPush = false;
+									HashMap<ResourcePath, IResourceStateAccessor> inputResourceToStateAccessor = new HashMap<>();
+									for (Edge eIn: dst.getInEdges()) {
+										DataFlowEdge dIn = (DataFlowEdge) eIn;
+										if (((PushPullAttribute) dIn.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
+											isContainedPush = true;
+											inputResourceToStateAccessor.put(((ResourceNode) dIn.getSource()).getResource(), JavaCodeGenerator.pushAccessor);
+										} else {
+											inputResourceToStateAccessor.put(((ResourceNode) dIn.getSource()).getResource(), JavaCodeGenerator.pullAccessor);
+										}
 									}
-								}
-								// for reference channel members
-								for (ChannelMember c: d.getChannel().getReferenceChannelMembers()) {
-									inputResourceToStateAccessor.put(c.getResource(), JavaCodeGenerator.pullAccessor);			// by pull data transfer
-								}
-								String[] sideEffects = new String[] {""};
-								// generate a return statement.
-								if (!isContainedPush) {
-									// All incoming edges are in PULL style.
-									String curState = d.getChannel().deriveUpdateExpressionOf(out, JavaCodeGenerator.pullAccessor).toImplementation(sideEffects);
-									getter.addStatement(sideEffects[0] + "return " + curState + ";");
-								} else {
-									// At least one incoming edge is in PUSH style.
-									String curState = d.getChannel().deriveUpdateExpressionOf(out, JavaCodeGenerator.pullAccessor, inputResourceToStateAccessor).toImplementation(sideEffects);
-									getter.addStatement(sideEffects[0] + "return " + curState + ";");
+									// for reference channel members
+									for (ChannelMember c: d.getChannel().getReferenceChannelMembers()) {
+										inputResourceToStateAccessor.put(c.getResource(), JavaCodeGenerator.pullAccessor);			// by pull data transfer
+									}
+									String[] sideEffects = new String[] {""};
+									// generate a return statement.
+									if (!isContainedPush) {
+										// All incoming edges are in PULL style.
+										String curState = d.getChannel().deriveUpdateExpressionOf(out, JavaCodeGenerator.pullAccessor).toImplementation(sideEffects);
+										getter.addStatement(sideEffects[0] + "return " + curState + ";");
+									} else {
+										// At least one incoming edge is in PUSH style.
+										String curState = d.getChannel().deriveUpdateExpressionOf(out, JavaCodeGenerator.pullAccessor, inputResourceToStateAccessor).toImplementation(sideEffects);
+										getter.addStatement(sideEffects[0] + "return " + curState + ";");
+									}
 								}
 							}
 						} 
@@ -203,24 +209,26 @@
 				TypeDeclaration type = typeMap.get(resourceName);
 				if (type != null) {
 					// getter method
-					MethodDeclaration getter = getGetterMethod(type);
-					if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-						Type resourceType = resource.getResource().getResourceStateType();
-						if (model.isPrimitiveType(resourceType)) {
-							getter.addStatement("return value;");							
-						} else {
-							// copy the current state to be returned as a 'value'
-							String implTypeName = resourceType.getImplementationTypeName();
-//							String interfaceTypeName = resourceType.getInterfaceTypeName();
-//							String concreteTypeName;
-//							if (interfaceTypeName.contains("<")) {
-//								String typeName = implTypeName.substring(0, implTypeName.indexOf("<"));
-//								String generics = interfaceTypeName.substring(interfaceTypeName.indexOf("<") + 1, interfaceTypeName.lastIndexOf(">"));
-//								concreteTypeName = typeName + "<" + generics + ">";
-//							} else {
-//								concreteTypeName = implTypeName;
-//							}
-							getter.addStatement("return new " + implTypeName + "(value);");
+					if (resource.getResource().getNumberOfParameters() == 0) {
+						MethodDeclaration getter = getGetterMethod(type, null);
+						if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+							Type resourceType = resource.getResource().getResourceStateType();
+							if (model.isPrimitiveType(resourceType)) {
+								getter.addStatement("return value;");							
+							} else {
+								// copy the current state to be returned as a 'value'
+								String implTypeName = resourceType.getImplementationTypeName();
+//								String interfaceTypeName = resourceType.getInterfaceTypeName();
+//								String concreteTypeName;
+//								if (interfaceTypeName.contains("<")) {
+//									String typeName = implTypeName.substring(0, implTypeName.indexOf("<"));
+//									String generics = interfaceTypeName.substring(interfaceTypeName.indexOf("<") + 1, interfaceTypeName.lastIndexOf(">"));
+//									concreteTypeName = typeName + "<" + generics + ">";
+//								} else {
+//									concreteTypeName = implTypeName;
+//								}
+								getter.addStatement("return new " + implTypeName + "(value);");
+							}
 						}
 					}
 					// methods for input events
@@ -230,28 +238,40 @@
 						for (ChannelMember out: outs) {
 							MethodDeclaration input = getInputMethod(type, out);
 							if (input != null) {
-								String[] sideEffects = new String[] {""};
-								Expression updateExp = entry.getKey().deriveUpdateExpressionOf(out, JavaCodeGenerator.pushAccessor);
-								String newState = updateExp.toImplementation(sideEffects);
-								String updateStatement;
-								if (updateExp instanceof Term && ((Term) updateExp).getSymbol().isImplWithSideEffect()) {
-									updateStatement = sideEffects[0];	
-								} else {
-									updateStatement = sideEffects[0] + "this.value = " + newState + ";";
+								// In the resource
+								if (resource.getResource().getNumberOfParameters() == 0) {
+									String[] sideEffects = new String[] {""};
+									Expression updateExp = entry.getKey().deriveUpdateExpressionOf(out, JavaCodeGenerator.pushAccessor);
+									String newState = updateExp.toImplementation(sideEffects);
+									String updateStatement;
+									if (updateExp instanceof Term && ((Term) updateExp).getSymbol().isImplWithSideEffect()) {
+										updateStatement = sideEffects[0];	
+									} else {
+										updateStatement = sideEffects[0] + "this.value = " + newState + ";";
+									}
+									if (input.getBody() == null || !input.getBody().getStatements().contains(updateStatement)) {
+										input.addFirstStatement(updateStatement);
+									}
 								}
-								if (input.getBody() == null || !input.getBody().getStatements().contains(updateStatement)) {
-									input.addFirstStatement(updateStatement);
-								}
+								
+								// In the main type
 								if (mainType != null) {
 									MethodDeclaration mainInput = getMethod(mainType, input.getName());
 									if (mainInput != null) {
 										String args = "";
-										String delimitar = "";
+										String delimiter = "";
+										for (Selector selector: entry.getKey().getAllSelectors()) {
+											if (selector.getExpression() instanceof Variable) {
+												Variable var = (Variable) selector.getExpression();
+												args += delimiter + var.getName();
+												delimiter = ", ";
+											}
+										}
 										if (out.getStateTransition().getMessageExpression() instanceof Term) {
 											Term message = (Term) out.getStateTransition().getMessageExpression();
 											for (Variable var: message.getVariables().values()) {
-												args += delimitar + var.getName();
-												delimitar = ", ";
+												args += delimiter + var.getName();
+												delimiter = ", ";
 											}
 										}
 										mainInput.addStatement("this." + resourceName + "." + input.getName() + "(" + args + ");");
@@ -286,9 +306,21 @@
 		return updates;
 	}
 
-	private static MethodDeclaration getGetterMethod(TypeDeclaration type) {
+	private static MethodDeclaration getGetterMethod(TypeDeclaration type, List<VariableDeclaration> params) {
 		for (MethodDeclaration m: type.getMethods()) {
-			if (m.getName().startsWith("get")) return m;
+			if (m.getName().startsWith("get")) {
+				if (m.getParameters() == null && (params == null || params.size() == 0)) return m;
+				if (m.getParameters() != null && params != null && m.getParameters().size() == params.size()) {
+					boolean matchParams = true;
+					for (int i = 0; i < m.getParameters().size(); i++) {
+						if (!m.getParameters().get(i).getType().equals(params.get(i).getType())) {
+							matchParams = false;
+							break;
+						}
+					}
+					if (matchParams) return m;
+				}
+			}
 		}
 		return null;
 	}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
index 7a77fae..e908f01 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
@@ -25,6 +25,7 @@
 import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.DataConstraintModel;
 import models.dataConstraintModel.ResourcePath;
+import models.dataConstraintModel.Selector;
 import models.dataFlowModel.DataTransferModel;
 import models.dataFlowModel.DataTransferChannel;
 import models.dataFlowModel.DataTransferChannel.IResourceStateAccessor;
@@ -69,10 +70,32 @@
 			String resourceName = rn.getResource().getResourceName().substring(0, 1).toUpperCase()
 					+ rn.getResource().getResourceName().substring(1);
 
-			// Declare the field to refer each resource in the main type.
-			TypeDeclaration type = new TypeDeclaration(resourceName);
-			type.addAnnotation(new Annotation("Component"));
-			type.addAnnotation(new Annotation("Path", "\"/" + rn.getResource().getResourceName() + "\""));
+			TypeDeclaration type = null;
+			for (CompilationUnit cu: codes) {
+				for (TypeDeclaration t: cu.types()) {
+					if (resourceName.equals(t.getTypeName())) {
+						type = t;
+						break;
+					}
+				}
+				if (type != null) break;
+			}
+			if (type == null) {
+				// Add compilation unit for each resource.
+				type = new TypeDeclaration(resourceName);
+				type.addAnnotation(new Annotation("Component"));
+				type.addAnnotation(new Annotation("Path", "\"/" + rn.getResource().getResourceName() + "\""));
+				
+				CompilationUnit cu = new CompilationUnit(type);
+				cu.addImport(new ImportDeclaration("java.util.*"));
+				cu.addImport(new ImportDeclaration("javax.ws.rs.*"));
+				cu.addImport(new ImportDeclaration("javax.ws.rs.client.*"));
+				cu.addImport(new ImportDeclaration("javax.ws.rs.core.*"));
+				cu.addImport(new ImportDeclaration("org.springframework.stereotype.Component"));
+				cu.addImport(new ImportDeclaration("com.fasterxml.jackson.databind.ObjectMapper"));
+				cu.addImport(new ImportDeclaration("com.fasterxml.jackson.core.JsonProcessingException"));
+				codes.add(cu);
+			}
 			
 			// Declare a client field and update methods from other resources.
 			boolean bDeclareClientField = false;
@@ -149,12 +172,26 @@
 //			}
 			
 			// Declare input methods in resources.
-			for (Channel cg : model.getIOChannels()) {
-				for (ChannelMember cm : ((DataTransferChannel) cg).getOutputChannelMembers()) {
+			Channel inCh = null;
+			for (Channel ch : model.getIOChannels()) {
+				for (ChannelMember cm : ((DataTransferChannel) ch).getOutputChannelMembers()) {
 					if (cm.getResource().equals(rn.getResource())) {
+						inCh = ch;
 						Expression message = cm.getStateTransition().getMessageExpression();
-						if (message.getClass() == Term.class) {
+						if (message instanceof Term) {
 							ArrayList<VariableDeclaration> params = new ArrayList<>();
+							String resourcePath = "\"";
+							for (Selector selector: ch.getAllSelectors()) {
+								if (selector.getExpression() instanceof Variable) {
+									Variable var = (Variable) selector.getExpression();
+									String paramName = var.getName();
+									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+									params.add(param);
+									resourcePath += "/{" + paramName + "}";
+								}
+							}
+							resourcePath += "\"";
 							for (Variable var: message.getVariables().values()) {
 								String paramName = var.getName();
 								VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
@@ -169,16 +206,42 @@
 							} else {
 								input.addAnnotation(new Annotation("POST"));
 							}
+							if (ch.getAllSelectors().size() > 0) {
+								input.addAnnotation(new Annotation("Path", resourcePath));
+							}
 							type.addMethod(input);
-						} else if (message.getClass() == Variable.class) {
-							MethodDeclaration input = new MethodDeclaration(
-									((Variable) cm.getStateTransition().getMessageExpression()).getName(),
-									false, typeVoid, null);
+						} else if (message instanceof Variable) {
+							ArrayList<VariableDeclaration> params = new ArrayList<>();
+							String resourcePath = "\"";
+							for (Selector selector: ch.getAllSelectors()) {
+								if (selector.getExpression() instanceof Variable) {
+									Variable var = (Variable) selector.getExpression();
+									String paramName = var.getName();
+									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+									params.add(param);
+									resourcePath += "/{" + paramName + "}";
+								}
+							}
+							resourcePath += "\"";
+							MethodDeclaration input = null;
+							if (params.size() > 0) {
+								input = new MethodDeclaration(
+										((Variable) cm.getStateTransition().getMessageExpression()).getName(),
+										false, typeVoid, params);
+							} else {
+								input = new MethodDeclaration(
+										((Variable) cm.getStateTransition().getMessageExpression()).getName(),
+										false, typeVoid, null);
+							}
 							if (cm.getStateTransition().isRightUnary()) {
 								input.addAnnotation(new Annotation("PUT"));
 							} else {
 								input.addAnnotation(new Annotation("POST"));
 							}
+							if (ch.getAllSelectors().size() > 0) {
+								input.addAnnotation(new Annotation("Path", resourcePath));
+							}
 							type.addMethod(input);
 						}
 					}
@@ -186,27 +249,45 @@
 			}
 			
 			// Declare the field to store the state in the type of each resource.
-			if (((StoreAttribute) rn.getAttribute()).isStored()) {
-				ResourcePath resId = rn.getResource();
-				type.addField(new FieldDeclaration(resId.getResourceStateType(), "value", getInitializer(resId)));
+			if (((StoreAttribute) rn.getAttribute()).isStored() && rn.getResource().getNumberOfParameters() == 0) {
+				ResourcePath res = rn.getResource();
+				type.addField(new FieldDeclaration(res.getResourceStateType(), "value", getInitializer(res)));
 			}
 			
 			// Declare the getter method to obtain the state in the type of each resource.
-			MethodDeclaration getter = new MethodDeclaration("getValue", rn.getResource().getResourceStateType());
-			getter.addAnnotation(new Annotation("Produces", "MediaType.APPLICATION_JSON"));
-			getter.addAnnotation(new Annotation("GET"));
-			type.addMethod(getter);
-			
-			// Add compilation unit for each resource.
-			CompilationUnit cu = new CompilationUnit(type);
-			cu.addImport(new ImportDeclaration("java.util.*"));
-			cu.addImport(new ImportDeclaration("javax.ws.rs.*"));
-			cu.addImport(new ImportDeclaration("javax.ws.rs.client.*"));
-			cu.addImport(new ImportDeclaration("javax.ws.rs.core.*"));
-			cu.addImport(new ImportDeclaration("org.springframework.stereotype.Component"));
-			cu.addImport(new ImportDeclaration("com.fasterxml.jackson.databind.ObjectMapper"));
-			cu.addImport(new ImportDeclaration("com.fasterxml.jackson.core.JsonProcessingException"));
-			codes.add(cu);
+			if (inCh == null) {
+				DataFlowEdge e = (DataFlowEdge) rn.getInEdges().iterator().next();
+				if (e != null) {
+					inCh = e.getChannel();
+				}
+			}
+			if (inCh != null) {
+				ArrayList<VariableDeclaration> params = new ArrayList<>();
+				String resourcePath = "\"";
+				for (Selector selector: inCh.getAllSelectors()) {
+					if (selector.getExpression() instanceof Variable) {
+						Variable var = (Variable) selector.getExpression();
+						String paramName = var.getName();
+						VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+						param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+						params.add(param);								
+						resourcePath += "/{" + paramName + "}";
+					}
+				}				
+				resourcePath += "\"";
+				MethodDeclaration getter = null;
+				if (params.size() > 0) {
+					getter = new MethodDeclaration("getValue", false, rn.getResource().getResourceStateType(), params);
+				} else {
+					getter = new MethodDeclaration("getValue", rn.getResource().getResourceStateType());
+				}
+				getter.addAnnotation(new Annotation("Produces", "MediaType.APPLICATION_JSON"));
+				getter.addAnnotation(new Annotation("GET"));
+				if (inCh.getAllSelectors().size() > 0) {
+					getter.addAnnotation(new Annotation("Path", resourcePath));
+				}
+				type.addMethod(getter);
+			}
 		}
 		
 		// Declare the Pair class.
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
index 9ad2995..6353287 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
@@ -170,11 +170,13 @@
 								}
 								if (paramConverter.length() > 0) update.addFirstStatement(paramConverter);
 							}
-							MethodDeclaration getter = getGetterMethod(dstType);
 							if (((StoreAttribute) dst.getAttribute()).isStored()) {
-								// returns the state stored in a field.
-								if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-									getter.addStatement("return value;");
+								if (dst.getResource().getNumberOfParameters() == 0) {
+									// returns the state stored in a field.
+									MethodDeclaration getter = getGetterMethod(dstType, null);
+									if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+										getter.addStatement("return value;");
+									}
 								}
 							}
 							// src side (for a chain of update method invocations)
@@ -272,22 +274,24 @@
 							}
 						} else {
 							// for pull (or push/pull) data transfer
-							MethodDeclaration getter = getGetterMethod(dstType);
-							if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-								// generate a return statement.
-								String[] sideEffects = new String[] {""};
-								String curState = d.getChannel().deriveUpdateExpressionOf(out, JerseyCodeGenerator.pullAccessor).toImplementation(sideEffects);		// no pull data transfer is included.
-								getter.addStatement(sideEffects[0] + "return " + curState + ";");
-								// For each reference channel member, get the current state of the reference side resource by pull data transfer.
-								for (ChannelMember c: d.getChannel().getReferenceChannelMembers()) {
-									String refResourceName = c.getResource().getResourceName();
-									Type refResourceType = c.getResource().getResourceStateType();
-									generatePullDataTransfer(getter, refResourceName, refResourceType);
+							if (dst.getResource().getNumberOfParameters() == 0) {
+								MethodDeclaration getter = getGetterMethod(dstType, null);
+								if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+									// generate a return statement.
+									String[] sideEffects = new String[] {""};
+									String curState = d.getChannel().deriveUpdateExpressionOf(out, JerseyCodeGenerator.pullAccessor).toImplementation(sideEffects);		// no pull data transfer is included.
+									getter.addStatement(sideEffects[0] + "return " + curState + ";");
+									// For each reference channel member, get the current state of the reference side resource by pull data transfer.
+									for (ChannelMember c: d.getChannel().getReferenceChannelMembers()) {
+										String refResourceName = c.getResource().getResourceName();
+										Type refResourceType = c.getResource().getResourceStateType();
+										generatePullDataTransfer(getter, refResourceName, refResourceType);
+									}
 								}
+								// get src side resource state by pull data transfer.
+								Type srcResourceType = src.getResource().getResourceStateType();
+								generatePullDataTransfer(getter, srcResourceName, srcResourceType);
 							}
-							// get src side resource state by pull data transfer.
-							Type srcResourceType = src.getResource().getResourceStateType();
-							generatePullDataTransfer(getter, srcResourceName, srcResourceType);
 						} 
 					}
 				}
@@ -299,9 +303,11 @@
 				TypeDeclaration type = typeMap.get(resourceName);
 				if (type != null) {
 					// getter method
-					MethodDeclaration getter = getGetterMethod(type);
-					if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
-						getter.addStatement("return value;");
+					if (resource.getResource().getNumberOfParameters() == 0) {
+						MethodDeclaration getter = getGetterMethod(type, null);
+						if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
+							getter.addStatement("return value;");
+						}
 					}
 					// methods for input events
 					Map<DataTransferChannel, Set<ChannelMember>> ioChannelsAndMembers = getIOChannelsAndMembers(resource, model);
@@ -310,17 +316,19 @@
 						for (ChannelMember out: outs) {
 							MethodDeclaration input = getInputMethod(type, out);
 							if (input != null) {
-								Expression updateExp = entry.getKey().deriveUpdateExpressionOf(out, JerseyCodeGenerator.pushAccessor);
-								String[] sideEffects = new String[] {""};
-								String newState = updateExp.toImplementation(sideEffects);
-								String updateStatement;
-								if (updateExp instanceof Term && ((Term) updateExp).getSymbol().isImplWithSideEffect()) {
-									updateStatement = sideEffects[0];								
-								} else {
-									updateStatement = sideEffects[0] + "this.value = " + newState + ";";
-								}
-								if (input.getBody() == null || !input.getBody().getStatements().contains(updateStatement)) {
-									input.addFirstStatement(updateStatement);
+								if (resource.getResource().getNumberOfParameters() == 0) {
+									Expression updateExp = entry.getKey().deriveUpdateExpressionOf(out, JerseyCodeGenerator.pushAccessor);
+									String[] sideEffects = new String[] {""};
+									String newState = updateExp.toImplementation(sideEffects);
+									String updateStatement;
+									if (updateExp instanceof Term && ((Term) updateExp).getSymbol().isImplWithSideEffect()) {
+										updateStatement = sideEffects[0];								
+									} else {
+										updateStatement = sideEffects[0] + "this.value = " + newState + ";";
+									}
+									if (input.getBody() == null || !input.getBody().getStatements().contains(updateStatement)) {
+										input.addFirstStatement(updateStatement);
+									}
 								}
 							}
 						}
@@ -533,9 +541,21 @@
 		return updates;
 	}
 
-	private static MethodDeclaration getGetterMethod(TypeDeclaration type) {
+	private static MethodDeclaration getGetterMethod(TypeDeclaration type, List<VariableDeclaration> params) {
 		for (MethodDeclaration m: type.getMethods()) {
-			if (m.getName().startsWith("get")) return m;
+			if (m.getName().startsWith("get")) {
+				if (m.getParameters() == null && (params == null || params.size() == 0)) return m;
+				if (m.getParameters() != null && params != null && m.getParameters().size() == params.size()) {
+					boolean matchParams = true;
+					for (int i = 0; i < m.getParameters().size(); i++) {
+						if (!m.getParameters().get(i).getType().equals(params.get(i).getType())) {
+							matchParams = false;
+							break;
+						}
+					}
+					if (matchParams) return m;
+				}
+			}
 		}
 		return null;
 	}
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
index 4a35051..a564792 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
@@ -1,6 +1,8 @@
 package models.dataConstraintModel;
 
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import models.algebra.Variable;
@@ -8,7 +10,7 @@
 public class Channel {
 	protected Channel parent = null;
 	protected String channelName;
-	protected Set<Selector> selectors = null;
+	protected List<Selector> selectors = null;
 	protected Set<ChannelMember> channelMembers = null;
 	protected String sourceText = null;
 	
@@ -20,29 +22,29 @@
 		this(null, channelName, variable);
 	}
 	
-	public Channel(String channelName, Set<Variable> variables) {
+	public Channel(String channelName, List<Variable> variables) {
 		this(null, channelName, variables);
 	}
 	
 	public Channel(Channel parent, String channelName) {
 		this.parent = parent;
 		this.channelName = channelName;
-		selectors = new HashSet<>();
+		selectors = new ArrayList<>();
 		channelMembers = new HashSet<>();
 	}
 	
 	public Channel(Channel parent, String channelName, Variable variable) {
 		this.parent = parent;
 		this.channelName = channelName;
-		selectors = new HashSet<>();
+		selectors = new ArrayList<>();
 		selectors.add(new Selector(variable));
 		channelMembers = new HashSet<>();
 	}
 	
-	public Channel(Channel parent, String channelName, Set<Variable> variables) {
+	public Channel(Channel parent, String channelName, List<Variable> variables) {
 		this.parent = parent;
 		this.channelName = channelName;
-		selectors = new HashSet<>();
+		selectors = new ArrayList<>();
 		for (Variable var: variables) {
 			selectors.add(new Selector(var));
 		}
@@ -61,11 +63,18 @@
 		return channelName;
 	}
 
-	public Set<Selector> getChannelSelectors() {
+	public List<Selector> getSelectors() {
 		return selectors;
 	}
 
-	public void setChannelSelectors(Set<Selector> selectors) {
+	public List<Selector> getAllSelectors() {
+		List<Selector> allSelectors = new ArrayList<>();
+		if (parent != null) allSelectors.addAll(parent.getAllSelectors());
+		allSelectors.addAll(selectors);
+		return allSelectors;
+	}
+
+	public void setSelectors(List<Selector> selectors) {
 		this.selectors = selectors;
 	}
 
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
index 10c8657..3f5ca6f 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
@@ -2,6 +2,7 @@
 
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import models.algebra.Expression;
@@ -28,7 +29,7 @@
 		this(null, channelName, variable);
 	}
 
-	public DataTransferChannel(String channelName, Set<Variable> variables) {
+	public DataTransferChannel(String channelName, List<Variable> variables) {
 		this(null, channelName, variables);
 	}
 	
@@ -46,7 +47,7 @@
 		referenceChannelMembers = new HashSet<>();
 	}
 	
-	public DataTransferChannel(DataTransferChannel parent, String channelName, Set<Variable> variables) {
+	public DataTransferChannel(DataTransferChannel parent, String channelName, List<Variable> variables) {
 		super(parent, channelName, variables);
 		inputChannelMembers = new HashSet<>();
 		outputChannelMembers = new HashSet<>();
diff --git a/AlgebraicDataflowArchitectureModel/src/tests/DataConstraintModelTest.java b/AlgebraicDataflowArchitectureModel/src/tests/DataConstraintModelTest.java
index 98f1962..25f1d61 100644
--- a/AlgebraicDataflowArchitectureModel/src/tests/DataConstraintModelTest.java
+++ b/AlgebraicDataflowArchitectureModel/src/tests/DataConstraintModelTest.java
@@ -25,12 +25,12 @@
 		Channel cio_setCustomerOff = new Channel("CIO_SetCustomerOff", new Variable("uid"));	// set customer's office
 		ChannelMember customer_off_1 = new ChannelMember(customer_off);
 		cio_setCustomerOff.addChannelMember(customer_off_1);
-		assertEquals(customer_off.getPathParams().get(0), cio_setCustomerOff.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(customer_off.getPathParams().get(0), cio_setCustomerOff.getSelectors().iterator().next().getExpression());
 		
 		Channel cio_setCompanyAdd = new Channel("CIO_SetCompanyAdd", new Variable("cid"));	// set companie's address
 		ChannelMember company_add_1 = new ChannelMember(company_add);
 		cio_setCompanyAdd.addChannelMember(company_add_1);		
-		assertEquals(company_add.getPathParams().get(0), cio_setCompanyAdd.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(company_add.getPathParams().get(0), cio_setCompanyAdd.getSelectors().iterator().next().getExpression());
 		
 		Channel c = new Channel("c", new Variable("uid"));		// update customer's address
 		ChannelMember customer_off_2 = new ChannelMember(customer_off);
@@ -39,8 +39,8 @@
 		c.addChannelMember(customer_off_2);
 		c.addChannelMember(company_add_2);
 		c.addChannelMember(customer_add_2);
-		assertEquals(customer_off.getPathParams().get(0), c.getChannelSelectors().iterator().next().getExpression());
-		assertEquals(customer_add.getPathParams().get(0), c.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(customer_off.getPathParams().get(0), c.getSelectors().iterator().next().getExpression());
+		assertEquals(customer_add.getPathParams().get(0), c.getSelectors().iterator().next().getExpression());
 		assertEquals(company_add.getPathParams().get(0), new Variable("cid"));
 		
 		model.addIOChannel(cio_setCustomerOff);
diff --git a/AlgebraicDataflowArchitectureModel/src/tests/DataFlowModelTest.java b/AlgebraicDataflowArchitectureModel/src/tests/DataFlowModelTest.java
index 939a9f1..29b9fac 100644
--- a/AlgebraicDataflowArchitectureModel/src/tests/DataFlowModelTest.java
+++ b/AlgebraicDataflowArchitectureModel/src/tests/DataFlowModelTest.java
@@ -35,7 +35,7 @@
 		DataTransferChannel cio_setCustomerOff = new DataTransferChannel("CIO_SetCustomerOff", new Variable("uid"));	// set customer's office (an input channel)
 		ChannelMember customer_off_1 = new ChannelMember(customer_off);
 		cio_setCustomerOff.addChannelMemberAsOutput(customer_off_1);
-		assertEquals(customer_off.getPathParams().get(0), cio_setCustomerOff.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(customer_off.getPathParams().get(0), cio_setCustomerOff.getSelectors().iterator().next().getExpression());
 		
 		// === cio_setCompanyAdd(cid) ===
 		//
@@ -44,7 +44,7 @@
 		DataTransferChannel cio_setCompanyAdd = new DataTransferChannel("CIO_SetCompanyAdd", new Variable("cid"));	// set companie's address (an input channel)
 		ChannelMember company_add_1 = new ChannelMember(company_add);
 		cio_setCompanyAdd.addChannelMemberAsOutput(company_add_1);		
-		assertEquals(company_add.getPathParams().get(0), cio_setCompanyAdd.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(company_add.getPathParams().get(0), cio_setCompanyAdd.getSelectors().iterator().next().getExpression());
 		
 		// === c ===
 		//		
@@ -59,8 +59,8 @@
 		c.addChannelMemberAsInput(customer_off_2);
 		c.addChannelMemberAsInput(company_add_2);
 		c.addChannelMemberAsOutput(customer_add_2);
-		assertEquals(customer_off.getPathParams().get(0), c.getChannelSelectors().iterator().next().getExpression());
-		assertEquals(customer_add.getPathParams().get(0), c.getChannelSelectors().iterator().next().getExpression());
+		assertEquals(customer_off.getPathParams().get(0), c.getSelectors().iterator().next().getExpression());
+		assertEquals(customer_add.getPathParams().get(0), c.getSelectors().iterator().next().getExpression());
 		assertEquals(company_add.getPathParams().get(0), new Variable("cid"));
 		
 		// Construct a data-flow architecture model.