一条关于安卓开发Intent的问题

MainActivity的代码

package black_lotus.blacklotus;

import android.os.Bundle;
 import android.app.Activity;
 import android.view.Menu;
 import android.widget.*;
 import android.view.View.OnClickListener;
 import android.view.View;
 import android.content.Intent;

public class MainActivity extends Activity {
 public final static String SECOND="SECOND";
 public final static String THIRD="THIRD";
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button btn=(Button)findViewById(R.id.btn1);
    btn.setOnClickListener(new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            Intent intent=new Intent();
            intent.setAction("black_lotus.blacklotus.MainActivity."+SECOND);
            intent.addCategory("black_lotus.blacklotus.MainActivity."+THIRD);
            startActivity(intent);
        }
    });
}

AndroidMainfest.xml的关于第二个窗口的代码

 android:name=".second_activity"
 android:label="第二个窗口">
        <intent-filter>
            <action android:name="SECOND"/>
           <category android:name="android.intent.category.THIRD"/> 
           <category android:name="android.intent.category.DEFAULT"/>
        </intent-filter>
    </activity>

        但是`logcat`里就是说`No Activity found to handle Intent`，我在网上查了不少资料也没有发现哪里有错，