import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class MyServer implements Runnable{
    //服务器连接
    public static ServerSocket serverSocket;
    //连接
    public static Socket socket;
    //端口
    public static final int PORT = 8888;
    public void run() {
        DataInputStream dis = null;
        DataOutputStream dos = null;
        try {
            serverSocket = new ServerSocket(PORT);
            System.out.println("正在等待客户端连接...");
            //这里处于等待状态，如果没有客户端连接，程序不会向下执行
            while(true){
                socket = serverSocket.accept();
                dis = new DataInputStream(socket.getInputStream());
                dos = new DataOutputStream(socket.getOutputStream());
                //读取数据
                String clientStr = dis.readUTF();
                //写出数据
                dos.writeUTF(clientStr);
                System.out.println("----客户端已成功连接!----");
                //得到客户端的IP
                System.out.println("客户端的IP =" + socket.getInetAddress());
                //得到客户端的端口号
                System.out.println("客户端的端口号 =" + socket.getPort());
                //得到本地端口号
                System.out.println("本地服务器端口号=" + socket.getLocalPort());
                System.out.println("-----------------------");
                System.out.println("客户端：" + clientStr);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {//我们把流的关闭写在finally里，即使读写出现问题，我们也能正常的关闭流！
            try {
                if (dis != null)
                    dis.close();
                if (dos != null)
                    dos.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    public static void main(String[] args){
        Thread desktopServerThread = new Thread(new MyServer());
        desktopServerThread.start();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.himi" android:versionCode="1" android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainActivity" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
    <uses-sdk android:minSdkVersion="4" />
    <uses-permission android:name="android.permission.INTERNET" />
</manifest> 

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">这里输入文字发给服务器</string>
    <string name="app_name">SocketConnect</string>
    <string name="send">发送</string>
    <string name="get">这里显示服务器发来的信息!</string> 
</resources>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:text="@string/hello" />
    <EditText android:id="@+id/edit" android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <Button android:id="@+id/Btn_commit" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:text="@string/send" />
    <TextView android:layout_width="fill_parent" android:id="@+id/tv"
        android:layout_height="wrap_content" android:text="@string/get" />
</LinearLayout> 

package com.himi;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

/**
 * @author Himi
 */
public class MainActivity extends Activity implements OnClickListener {
    private Button btn_ok;
    private EditText edit;
    private TextView tv;
    //Socket用于连接服务器获取输入输出流
    private Socket socket;
    //服务器server/IP地址
    private final String ADDRESS = "10.203.8.167";
    //服务器端口
    private final int PORT = 8888;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.main);
        btn_ok = (Button) findViewById(R.id.Btn_commit);
        tv = (TextView) findViewById(R.id.tv);
        edit = (EditText) findViewById(R.id.edit);
        btn_ok.setOnClickListener(this);
    }
    public void onClick(View v) {
        if (v == btn_ok) {
            DataInputStream dis = null;
            DataOutputStream dos = null;
            try {
                //阻塞函数，正常连接后才会向下继续执行
                socket = new Socket(ADDRESS, PORT);
                //socket = new Socket("localhost", PORT);
                dis = new DataInputStream(socket.getInputStream());
                dos = new DataOutputStream(socket.getOutputStream());
                //向服务器写数据
                dos.writeUTF(edit.getText().toString());
                String temp = "I say:";
                temp += edit.getText().toString();
                temp += "\n";
                temp += "Server say:";
                //读取服务器发来的数据
                temp += dis.readUTF();
                tv.setText(temp);
            } catch (IOException e) {
                Log.e("Himi", "Stream error!");
                e.printStackTrace();
            } finally {
                try {
                    if (dis != null)
                        dis.close();
                    if (dos != null)
                        dos.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}