关于socket通信的android与pc端连接，为什么我定义的socket是为空的，连接不上pc端

Question

服务器端代码：

package mytable;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.net.ServerSocket;

import java.net.Socket;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JTextArea;

import javax.swing.JTextField;

public class MyServer implements ActionListener {

/**

* 服务器端

* */

private Window window;

private ServerSocket server;

private static Socket socket;

private JButton button;

private static JTextArea area;

private JTextField field;

// private BufferedWriter writer;

private OutputStream writer;

private static BufferedReader reader;

// 存放TextField中的字符串

private static String fromClient;

public MyServer() {

window = new Window("服务器：");

button = window.getButton();

area = window.getJTextArea();

field = window.getTextField();

button.addActionListener(this);

try {

//监听端口5000

server = new ServerSocket(5000);

System.out.println("服务器已创建，正在等待客户端连接。。。");

socket = server.accept();

System.out.println("客户端已连接");

//打开输入输出流

writer = socket.getOutputStream();

reader = new BufferedReader(new InputStreamReader(

socket.getInputStream()));

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

try {

socket.close();

} catch (IOException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

}

}

public static void main(String[] args) throws InterruptedException {

new MyServer();

// 创建线程去读取客户端发来的数据

new Thread(new Runnable() {

@Override

public void run() {

try {

while (socket != null) {

fromClient = reader.readLine();

area.append("客户端：" + fromClient + '\n');

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

try {

reader.close();

} catch (IOException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

}

}

}).start();

}

/**

* 按钮监听方法，点击按钮时触发该方法。

* */

@Override

public void actionPerformed(ActionEvent e) {

String me = field.getText().toString() + '\n';

area.append("服务器：" + me);

field.setText("");

try {

writer.write(me.getBytes("utf-8"));

//刷新输出流

writer.flush();

} catch (IOException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

try {

writer.close();

} catch (IOException e2) {

// TODO Auto-generated catch block

e2.printStackTrace();

}

}

}

}

客户端代码

package com.example.client;

import java.io.BufferedReader;

import java.io.OutputStream;

import java.net.Socket;

import android.support.v7.app.ActionBarActivity;

import android.support.v7.app.ActionBar;

import android.support.v4.app.Fragment;

import android.os.Bundle;

import android.os.Handler;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.os.Build;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.net.Socket;

import java.net.UnknownHostException;

import android.os.Bundle;

import android.os.Handler;

import android.os.Looper;

import android.os.Message;

import android.support.v7.app.ActionBarActivity;

import android.text.method.ScrollingMovementMethod;

import android.util.Log;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

public EditText editText;

public Button button;

// 输出流

public BufferedReader in;

// 输入流

// private BufferedWriter out;

//输入流

// private InputStream in;

//输出流

public OutputStream out;

// 客户端socket

public Socket socket;

// 显示数据

public TextView textView;

// 用来存放要传递给客户端的数据

public static String data;

//handler发送处理消息

public Handler handler;

public String b;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

editText = (EditText) findViewById(R.id.editText);

button = (Button) findViewById(R.id.send);

textView = (TextView) findViewById(R.id.textView);

//设置textView可以滚动

textView.setMovementMethod(ScrollingMovementMethod.getInstance());

handler = new Handler(new Handler.Callback() {

@Override

public boolean handleMessage(Message msg) {

if(msg.what == 0x1314)

{

textView.append("服务器：" + b + '\n');

}

return true;

}

});

new Thread(new Runnable() {

@Override

public void run() {

try {

socket = new Socket("127.0.0.1", 5000);

Log.e("--->", "已发出链接请求");

in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

out = socket.getOutputStream();

while (socket != null) {

b = in.readLine();

// textView.append("服务器：" + b + '\n');

handler.sendEmptyMessage(0x1314);

}

} catch (UnknownHostException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}).start();

button.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View arg0) {

data = editText.getText().toString();

textView.append("客户端说：" + data + '\n');

editText.setText("");

try {

if (socket != null) {

out.write((data + '\n').getBytes("GBK"));

out.flush();

}

else  if(socket==null)

Log.e("--->", "服务器未连接，无法获得输出流");

} catch (IOException e) {

e.printStackTrace();

}

}

});

}

}