IPC 机制---使用Socket

IPC 机制---使用Socket

Socket 也称套接字 ，是网络通信中的概念，它分为流式套接字 和用户数据报套接字 两种

流式套接字 ：对应于传输控制层的TCP协议 TCP协议 是面向连接的协议，提供稳定的双向通信功能，TCP的连接需要经过三次握手才能完成，为了提供稳定的数据传输功能，其本身提供了超时重传机制，因此具有很高的稳定性。

用户数据报套接字：对应于传输控制层的UDP协议，UDP是无连接的，提供不稳定的单向通信功能，当然UDP也可以实现双向通信功能。在性能上UDP具有更好的效率，其缺点是不能保证数据一定能够正确传输，尤其是在网络拥塞的情况下。

使用 Socket 来进行通信首先需要声明权限

    <uses-permission android:name= "android.permission.INTERNET" />

    <uses-permission android:name= "android.permission.ACCESS_NETWORK_STATE" />

其次不能够在主线程中访问网络，因为这会导致我们的程序无法在Android4.0 以上的设备运行。而且进行网络操作很可能是耗时的，如果放在主线程的中，会影响程序的响应效率。

服务端代码：

public class TCPServerService extends Service {

    private boolean mIsServiceDestoryed = false;

    private String[] mDefinedMessages = new String[] {

            "浣犲ソ鍟婏紝鍝堝搱" ,

            "璇烽棶浣犲彨浠�涔堝悕瀛楀憖锛�" ,

            "浠婂ぉ鍖椾含澶╂皵涓嶉敊鍟婏紝shy" ,

            "浣犵煡閬撳悧锛熸垜鍙槸鍙互鍜屽涓汉鍚屾椂鑱婂ぉ鐨勫摝" ,

            "缁欎綘璁蹭釜绗戣瘽鍚э細鎹鐖辩瑧鐨勪汉杩愭皵涓嶄細澶樊锛屼笉鐭ラ亾鐪熷亣銆�"

    };

    @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 {

                    // 鎺ュ彈瀹㈡埛绔姹�

                    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( "娆㈣繋鏉ュ埌鑱婂ぉ瀹わ紒" );

        while (!mIsServiceDestoryed ) {

            String str = in.readLine();

            System. out.println("msg from client:" + str);

            if (str == null ) {

            //客户端断开连接

                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." );

        // 鍏抽棴娴�

        MyUtils. close(out);

        MyUtils. close(in);

        client.close();

    }

}

客户端代码：

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 {

            // 鎺ユ敹鏈嶅姟鍣ㄧ鐨勬秷鎭�

            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();

        }

    }

}