diff --git a/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java b/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
index a184b71..e775591 100644
--- a/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
+++ b/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
@@ -14,12 +14,10 @@
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main_java);
 
-        findViewById(R.id.flowable_btn).setOnClickListener(view -> {
-            rxProcess.flowableReactiveStreams();
-        });
+        findViewById(R.id.flowable_btn).setOnClickListener(view -> rxProcess.flowableReactiveStreams());
 
-        findViewById(R.id.observable_btn).setOnClickListener(view -> {
-            rxProcess.observable();
-        });
+        findViewById(R.id.observable_btn).setOnClickListener(view -> rxProcess.observable());
+
+        findViewById(R.id.just_btn).setOnClickListener(view -> rxProcess.just());
     }
 }
diff --git a/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java b/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
index 59ef72c..3f8dd20 100644
--- a/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
+++ b/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
@@ -119,4 +119,13 @@
                         }
                 );
     }
+
+    /**
+     * 引数のデータを通知するFLowableを作成
+     * 引数は10個まで
+     */
+    public void just(){
+        Flowable<String> flowable = Flowable.just("A","B","C","D","E","F","G","H","I","J");
+        flowable.subscribe(new DebugSubscriber<>());
+    }
 }
diff --git a/app/src/main/res/layout/activity_main_java.xml b/app/src/main/res/layout/activity_main_java.xml
index e9845d8..bb4850c 100644
--- a/app/src/main/res/layout/activity_main_java.xml
+++ b/app/src/main/res/layout/activity_main_java.xml
@@ -25,6 +25,14 @@
             android:text="observable"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/flowable_btn" />
+
+        <Button
+            android:id="@+id/just_btn"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="just"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/observable_btn" />
     </android.support.constraint.ConstraintLayout>
 
 </ScrollView>