android tcp socket继续发送

Question

MainActivity

public class MainActivity extends FragmentActivity implements ActionBar.OnNavigationListener {

/**
 * The serialization (saved instance state) Bundle key representing the
 * current dropdown position.
 */
private static final String STATE_SELECTED_NAVIGATION_ITEM = "selected_navigation_item";
public final static String EXTRA_MESSAGE = "com.example.deltaskype.MESSAGE";


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

    // Set up the action bar to show a dropdown list.
    final ActionBar actionBar = getActionBar();
    actionBar.setDisplayShowTitleEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);

    // Set up the dropdown list navigation in the action bar.
    actionBar.setListNavigationCallbacks(
            // Specify a SpinnerAdapter to populate the dropdown list.
            new ArrayAdapter<String>(
                    actionBar.getThemedContext(),
                    android.R.layout.simple_list_item_1,
                    android.R.id.text1,
                    new String[] {
                            getString(R.string.title_section1),
                            getString(R.string.title_section2),
                            getString(R.string.title_section3),
                    }),
            this);
}


@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    // Restore the previously serialized current dropdown position.
    if (savedInstanceState.containsKey(STATE_SELECTED_NAVIGATION_ITEM)) {
        getActionBar().setSelectedNavigationItem(
                savedInstanceState.getInt(STATE_SELECTED_NAVIGATION_ITEM));
    }
}

@Override
public void onSaveInstanceState(Bundle outState) {
    // Serialize the current dropdown position.
    outState.putInt(STATE_SELECTED_NAVIGATION_ITEM,
            getActionBar().getSelectedNavigationIndex());
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onNavigationItemSelected(int position, long id) {
    // When the given dropdown item is selected, show its contents in the
    // container view.
    Fragment fragment = new DummySectionFragment();
    Bundle args = new Bundle();
    args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
    fragment.setArguments(args);
    getSupportFragmentManager().beginTransaction()
            .replace(R.id.container, fragment)
            .commit();
    return true;
}

/**
 * A dummy fragment representing a section of the app, but that simply
 * displays dummy text.
 */
public static class DummySectionFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    public static final String ARG_SECTION_NUMBER = "section_number";

    public DummySectionFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main_dummy, container, false);
        TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
        dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
        return rootView;
    }
}


public void sendMessage(View view) {
    // Do something in response to button
    Intent intent = new Intent(this, DisplayMessageActivity.class);
    EditText editText = (EditText) findViewById(R.id.edit_message);
    String message = editText.getText().toString();
    intent.putExtra(EXTRA_MESSAGE, message);
     startActivity(intent);


}

DisplayMessageActivity

package com.example.deltaskype;

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

import android.os.Build;
import android.os.Bundle;
import android.os.StrictMode;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.support.v4.app.NavUtils;

public class DisplayMessageActivity extends Activity {

    @SuppressLint("NewApi")
    @Override
    public void onCreate(Bundle savedInstanceState) {

         if (android.os.Build.VERSION.SDK_INT > 9) {
              StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
              StrictMode.setThreadPolicy(policy);
            }

        super.onCreate(savedInstanceState);

        // Get the message from the intent
        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        // Create the text view
        TextView textView = new TextView(this);
        textView.setTextSize(40);
        textView.setText(message);

        // Set the text view as the activity layout
        setContentView(textView);
        Socket socket = null;
        try {
            socket = new Socket("X.X.X.X", 13134);
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }   

         OutputStream out = null;
            try {
                out = socket.getOutputStream();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }       
            PrintWriter output = new PrintWriter(out);         


            output.println("<request><auth><user>X</user><password>X</password></auth><action><name>makeCall</name><data><dialnum>"+message+"</dialnum></data></action></request>\n");              
            output.flush();
            output.close();
            try {
                socket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }                                    

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case android.R.id.home:
            NavUtils.navigateUpFromSameTask(this);
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

这用于呼叫座机，但它多次执行呼叫，

如果第一次进行通话，则会给出OK的响应，任何想法为何多次拨打电话（即接听电话并将其放下并再次响铃！）