android：java.lang.NoClassDefFoundError：com.google.android.gms.R $ styleable

My activity code

我的活动代码

package com.example.testmap;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import com.google.android.gms.maps.SupportMapFragment;

public class MainActivity extends FragmentActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}
package com.example