Android Change Imageview with Button Click

[MaheshKale]

I am trying to change the background of imageview using the following code.

Here's my xml code.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.devnami.maya.maya.MainActivity"
    > <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/forest"
        android:adjustViewBounds="true"
        android:scaleType="fitXY"
        android:id="@+id/view1"

        /> <ImageButton
          android:id="@+id/button1"
          android:layout_width="45dp"
          android:layout_height="45dp"
          android:textStyle="bold"
          android:textColor="#FFFFFF"
          android:background="@drawable/flower"
          android:layout_alignParentBottom="true"
          android:layout_alignParentLeft="true"

          /> </RelativeLayout>

And here's my mainactivity.java code.

public class MainActivity extends AppCompatActivity {

 super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageButton one = (ImageButton) this.findViewById(R.id.button1);

ImageButton one = (ImageButton) this.findViewById(R.id.button1);

one.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {

          ImageView iv =(ImageView)this.findViewById(R.id.view1)

                int i = 0;
                if (i == 0) {

                    iv.setImageResource(R.drawable.mountain));
                    i++;
                } else if (i == 1) {
                    iv.setImageResource(R.drawable.seashore3);
                    i++;
                } else if (i == 2) {
                    iv.setImageResource(R.drawable.night1);
                    i++;
                } else if (i == 3) {
                    iv.setImageResource(R.drawable.forest);
                    i = 0;
                }
            }

        });

I execute this code there seems to be no errors during the build. When I run the app on the phone, it seems the button action leads to crash message and app closes.

Any idea how to resolve this?