diff --git a/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java b/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
index ac684e7..b029fc4 100644
--- a/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
+++ b/app/src/main/java/org/ntlab/developrx/JavaMainActivity.java
@@ -24,6 +24,7 @@
         findViewById(R.id.error_btn).setOnClickListener(view -> rxProcess.error());
         findViewById(R.id.map_btn).setOnClickListener(view -> rxProcess.map());
         findViewById(R.id.empty_btn).setOnClickListener(view -> rxProcess.empy());
-        findViewById(R.id.flatmap_btn).setOnClickListener(view -> rxProcess.flatmap());
+        findViewById(R.id.flatmap_1_btn).setOnClickListener(view -> rxProcess.flatmap1());
+        findViewById(R.id.flatmap_2_btn).setOnClickListener(view -> rxProcess.flatmap2());
     }
 }
diff --git a/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java b/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
index aeca684..49a8d1e 100644
--- a/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
+++ b/app/src/main/java/org/ntlab/developrx/JavaRxProcess.java
@@ -193,7 +193,7 @@
     /**
      * 受け取ったデータをFlowable/Observableに変換し、そのFlowable/Obsevableが持つデータを通知する
      */
-    public void flatmap() {
+    public void flatmap1() {
         Flowable<String> flowable = Flowable.just("A", "", "B", "", "C")
                 .flatMap(data -> {
                     if (data.isEmpty()) {
@@ -204,4 +204,13 @@
                 });
         flowable.subscribe(new DebugSubscriber<>());
     }
+
+    public void flatmap2() {
+        Flowable<String> flowable = Flowable.range(1, 3)
+                .flatMap(
+                        data -> Flowable.interval(100L, TimeUnit.MILLISECONDS).take(3),
+                        (sourceData, newData) -> "[" + sourceData + "] " + newData
+                );
+        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 9f3b624..53f4a00 100644
--- a/app/src/main/res/layout/activity_main_java.xml
+++ b/app/src/main/res/layout/activity_main_java.xml
@@ -91,13 +91,21 @@
             app:layout_constraintTop_toBottomOf="@id/map_btn" />
 
         <Button
-            android:id="@+id/flatmap_btn"
+            android:id="@+id/flatmap_1_btn"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:text="flatmap"
+            android:text="flatmap(1)"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/empty_btn" />
 
+        <Button
+            android:id="@+id/flatmap_2_btn"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="flatmap(2)"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/flatmap_1_btn" />
+
     </android.support.constraint.ConstraintLayout>
 
 </ScrollView>