1、创建TCPserver类（该类要创建为service类型，如下图）

其中代码如下

package com.zhongjian.zjqr;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.Looper;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;

public class TCPServer extends Service {
    public static Socket socket;
    public static PrintStream output;
    boolean conn = false;
    String ip;
    String port;
    public TCPServer() {
    }
    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        com.zhongjian.zjqr.TCPServer.MyThread myThread = new com.zhongjian.zjqr.TCPServer.MyThread();
        new Thread(myThread).start();
//        ********在最终应用时取消注释下行，用于动态改变的IP和端口的连接********
        ip=intent.getStringExtra("IP");
        port=intent.getStringExtra("port");
        System.out.println("IP地址："+intent.getStringExtra("IP")+"端口号："+intent.getStringExtra("port"));
//        ********可在其他activity中设置IP和端口号通过上面的方式进行获取******** return super.onStartCommand(intent, flags, startId);
        return super.onStartCommand(intent, flags, startId);
    }
    //socket连接线程
    class MyThread implements Runnable{
        @Override
        public void run(){
            try {
                socket = new Socket();
                SocketAddress socAddress = new InetSocketAddress(ip ,Integer.valueOf(port));
                try{
                    socket.connect(socAddress, 5000);
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                    System.out.println("连接失败");
                }
                if(socket.isConnected()){
                    //新建Var中定义全局boolean变量connServer，可以作为连接通断的依据*
                    //Var.connServer = true;
                    System.out.println("连接成功");

                }
                InputStream inputstream = socket.getInputStream();
                /* 获取输出流 */
                output = new PrintStream(socket.getOutputStream(), true, "utf-8");
                conn = true;

                byte buffer[] = new byte[100];//接收数组的长度
                int len2 ;
                String receiveData;
                //非阻塞式连接
                while(conn){
                    //接收网络数据
                    if( (len2 = inputstream.read(buffer)) != -1){
                        receiveData = new String(buffer, 0, len2);
                        Intent CMDintent = new Intent();
                        CMDintent.setAction("com.example.communication.data");
                        CMDintent.putExtra("data", buffer);//buffer为数组，receivedata为文本
                        sendBroadcast(CMDintent);
                    }else{
                        break;
                    }
                }
                output.close();
                socket.close();
                Looper.loop();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                // Looper.prepare();
                //Var定义的全局boolean变量connServer，可以作为连接通断的依据*
                //Var.connServer=false;
                System.out.println("显示连接已断开");
            }
        }
    };
    //发送方法：
    public static void send(final byte[] arr)
    {
        new Thread(new Runnable() {
            public void run() {
                if (socket.isConnected()) {
                    try {
                        output.write(arr);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }
}

2、在其它页面调用Intent方式，代码如下：

  Intent intentTCP=new Intent(ListActivity.this,TCPServer.class);
  intentTCP.putExtra("IP","120.48.30.130");
  intentTCP.putExtra("port","8001");
  startService(intentTCP);

注：可以定义全局boolean变量来获取socket的连接状态。该变量可以放在判断已经连接条件后（设为true）面，如果socket已经断开，将该变量放在抛出异常判断设为false。（以上代码有体现）