使用Socket实现安卓中IPC

　　网络上的两个程序通过一个双向的通信连接实现数据的交换，这个连接的一端称为一个socket。
　　建立网络通信连接至少要一对端口号(socket)。socket本质是编程接口(API)，对TCP/IP的封装，TCP/IP也要提供可供程序员做网络开发所用的接口，这就是Socket编程接口；HTTP是轿车，提供了封装或者显示数据的具体形式;Socket是发动机，提供了网络通信的能力。
　　Socket的英文原义是“孔”或“插座”。作为BSD UNIX的进程通信机制，取后一种意思。通常也称作”套接字”，用于描述IP地址和端口，是一个通信链的句柄，可以用来实现不同虚拟机或不同计算机之间的通信。在Internet上的主机一般运行了多个服务软件，同时提供几种服务。每种服务都打开一个Socket，并绑定到一个端口上，不同的端口对应于不同的服务。Socket正如其英文原意那样，像一个多孔插座。一台主机犹如布满各种插座的房间，每个插座有一个编号，有的插座提供220伏交流电， 有的提供110伏交流电，有的则提供有线电视节目。 客户软件将插头插到不同编号的插座，就可以得到不同的服务。

在Android中使用Socket实现聊天室功能

public class TCPClientActivity extends Activity implements OnClickListener {    private static final int MESSAGE_RECEIVE_NEW_MSG = 1;    private static final int MESSAGE_SOCKET_CONNECTED = 2;    private Button mSendButton;    private TextView mMessageTextView;    private EditText mMessageEditText;    private PrintWriter mPrintWriter;    private Socket mClientSocket;    @SuppressLint("HandlerLeak")    private Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {            case MESSAGE_RECEIVE_NEW_MSG: {                mMessageTextView.setText(mMessageTextView.getText()                        + (String) msg.obj);                break;            }            case MESSAGE_SOCKET_CONNECTED: {                mSendButton.setEnabled(true);                break;            }            default:                break;            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_tcpclient);        mMessageTextView = (TextView) findViewById(R.id.msg_container);        mSendButton = (Button) findViewById(R.id.send);        mSendButton.setOnClickListener(this);        mMessageEditText = (EditText) findViewById(R.id.msg);        Intent service = new Intent(this, TCPServerService.class);        startService(service);        new Thread() {            @Override            public void run() {                connectTCPServer();            }        }.start();    }    @Override    protected void onDestroy() {        if (mClientSocket != null) {            try {                mClientSocket.shutdownInput();                mClientSocket.close();            } catch (IOException e) {                e.printStackTrace();            }        }        super.onDestroy();    }    @Override    public void onClick(View v) {        if (v == mSendButton) {            final String msg = mMessageEditText.getText().toString();            if (!TextUtils.isEmpty(msg) && mPrintWriter != null) {                mPrintWriter.println(msg);                mMessageEditText.setText("");                String time = formatDateTime(System.currentTimeMillis());                final String showedMsg = "self " + time + ":" + msg + "\n";                mMessageTextView.setText(mMessageTextView.getText() + showedMsg);            }        }    }    @SuppressLint("SimpleDateFormat")    private String formatDateTime(long time) {        return new SimpleDateFormat("(HH:mm:ss)").format(new Date(time));    }    private void connectTCPServer() {        Socket socket = null;        while (socket == null) {            try {                socket = new Socket("localhost", 8688);                mClientSocket = socket;                mPrintWriter = new PrintWriter(new BufferedWriter(                        new OutputStreamWriter(socket.getOutputStream())), true);                mHandler.sendEmptyMessage(MESSAGE_SOCKET_CONNECTED);                System.out.println("connect server success");            } catch (IOException e) {                SystemClock.sleep(1000);                System.out.println("connect tcp server failed, retry...");            }        }        try {            // 接收服务器端的消息            BufferedReader br = new BufferedReader(new InputStreamReader(                    socket.getInputStream()));            while (!TCPClientActivity.this.isFinishing()) {                String msg = br.readLine();                System.out.println("receive :" + msg);                if (msg != null) {                    String time = formatDateTime(System.currentTimeMillis());                    final String showedMsg = "server " + time + ":" + msg                            + "\n";                    mHandler.obtainMessage(MESSAGE_RECEIVE_NEW_MSG, showedMsg)                            .sendToTarget();                }            }            System.out.println("quit...");            MyUtils.close(mPrintWriter);            MyUtils.close(br);            socket.close();        } catch (IOException e) {            e.printStackTrace();        }    }}

布局文件 activity_tcpclient.xml

public class TCPServerService extends Service {    private boolean mIsServiceDestoryed = false;    private String[] mDefinedMessages = new String[] {            "你好啊，哈哈",            "请问你叫什么名字呀？",            "今天北京天气不错啊，shy",            "你知道吗？我可是可以和多个人同时聊天的哦",            "给你讲个笑话吧：据说爱笑的人运气不会太差，不知道真假。"    };    @Override    public void onCreate() {        new Thread(new TcpServer()).start();        super.onCreate();    }    @Override    public IBinder onBind(Intent intent) {        return null;    }    @Override    public void onDestroy() {        mIsServiceDestoryed = true;        super.onDestroy();    }    private class TcpServer implements Runnable {        @SuppressWarnings("resource")        @Override        public void run() {            ServerSocket serverSocket = null;            try {                serverSocket = new ServerSocket(8688);            } catch (IOException e) {                System.err.println("establish tcp server failed, port:8688");                e.printStackTrace();                return;            }            while (!mIsServiceDestoryed) {                try {                    // 接受客户端请求                    final Socket client = serverSocket.accept();                    System.out.println("accept");                    new Thread() {                        @Override                        public void run() {                            try {                                responseClient(client);                            } catch (IOException e) {                                e.printStackTrace();                            }                        };                    }.start();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }    private void responseClient(Socket client) throws IOException {        // 用于接收客户端消息        BufferedReader in = new BufferedReader(new InputStreamReader(                client.getInputStream()));        // 用于向客户端发送消息        PrintWriter out = new PrintWriter(new BufferedWriter(                new OutputStreamWriter(client.getOutputStream())), true);        out.println("欢迎来到聊天室！");        while (!mIsServiceDestoryed) {            String str = in.readLine();            System.out.println("msg from client:" + str);            if (str == null) {                break;            }            int i = new Random().nextInt(mDefinedMessages.length);            String msg = mDefinedMessages[i];            out.println(msg);            System.out.println("send :" + msg);        }        System.out.println("client quit.");        // 关闭流        MyUtils.close(out);        MyUtils.close(in);        client.close();    }}