diff --git a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
index ae548ee..d1cb9de 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
@@ -93,10 +93,18 @@
 				// map or list.
 				if (DataConstraintModel.typeList.isAncestorOf(res.getResourceStateType())) {
 					// list.
-					return langSpec.newListType(getComponentName(child, langSpec));
+					if (generatesComponent(child)) {
+						return langSpec.newListType(getComponentName(child, langSpec));
+					} else {
+						return langSpec.newListType(getImplStateType(child, langSpec).getImplementationTypeName());
+					}
 				} else if (DataConstraintModel.typeMap.isAncestorOf(res.getResourceStateType())) {
 					// map.
-					return langSpec.newMapType(DataConstraintModel.typeString, getComponentName(child, langSpec));
+					if (generatesComponent(child)) {
+						return langSpec.newMapType(DataConstraintModel.typeString, getComponentName(child, langSpec));
+					} else {
+						return langSpec.newMapType(DataConstraintModel.typeString, getImplStateType(child, langSpec).getImplementationTypeName());
+					}
 				}
 				return null;
 			} else {
@@ -105,6 +113,12 @@
 			}
 		}
 	}
+	
+	public static boolean generatesComponent(ResourceHierarchy res) {
+		return res.getParent() == null || !(res.getChildren() == null || res.getChildren().size() == 0);
+//		Type resType = res.getResourceStateType();
+//		return DataConstraintModel.typeJson.isAncestorOf(resType) || DataConstraintModel.typeList.isAncestorOf(resType) || DataConstraintModel.typeMap.isAncestorOf(resType);
+	}
 
 	/**
 	 * Generate source codes in specified language from data-flow/control-flow graph.
@@ -336,23 +350,23 @@
 	}
 
 	protected void declareAccessorInMainComponent(TypeDeclaration mainComponent, ResourceNode accessRes, MethodDeclaration stateGetter, ILanguageSpecific langSpec) {
-		List<VariableDeclaration> mainParams = new ArrayList<>();
+		List<VariableDeclaration> mainGetterParams = new ArrayList<>();
 		int v = 1;
 		for (Selector selector: accessRes.getAllSelectors()) {
 			if (selector.getExpression() instanceof Variable) {
 				Variable var = (Variable) selector.getExpression();
-				mainParams.add(langSpec.newVariableDeclaration(var.getType(), var.getName()));
+				mainGetterParams.add(langSpec.newVariableDeclaration(var.getType(), var.getName()));
 			} else if (selector.getExpression() instanceof Term) {
 				Term var = (Term) selector.getExpression();
-				mainParams.add(new VariableDeclaration(var.getType(), "v" + v));
+				mainGetterParams.add(new VariableDeclaration(var.getType(), "v" + v));
 			}
 			v++;
 		}
 		MethodDeclaration accessor = null;
-		if (mainParams.size() == 0) {
+		if (mainGetterParams.size() == 0) {
 			accessor = langSpec.newMethodDeclaration(getterPrefix + getComponentName(accessRes.getResourceHierarchy(), langSpec), getImplStateType(accessRes.getResourceHierarchy(), langSpec));
 		} else {
-			accessor = langSpec.newMethodDeclaration(getterPrefix + getComponentName(accessRes.getResourceHierarchy(), langSpec), false, getImplStateType(accessRes.getResourceHierarchy(), langSpec), mainParams);
+			accessor = langSpec.newMethodDeclaration(getterPrefix + getComponentName(accessRes.getResourceHierarchy(), langSpec), false, getImplStateType(accessRes.getResourceHierarchy(), langSpec), mainGetterParams);
 		}
 		Block block = new Block();
 		Expression getState = JavaCodeGenerator.pullAccessor.getCurrentStateAccessorFor(accessRes.getOutSideResource(), null);
@@ -500,8 +514,7 @@
 						}
 					}
 					
-					if (target.getResourceHierarchy().getNumParameters() > 0 
-							|| (target.getResourceHierarchy().getChildren() != null && target.getResourceHierarchy().getChildren().size() > 0)) {
+					if (generatesComponent(target.getResourceHierarchy())) {
 						Term newGetter = new Term(new Symbol(getterOfResourceState, 1, Symbol.Type.METHOD));
 						newGetter.addChild(getter);
 						getter = newGetter;