通过socket测试工具在电脑上发送消息，Android真机可以收到响应BufferedReader.ready()返回true，但是readline却一直阻塞。

原因：readline()只有在遇到换行符的时候才会结束，因为发消息的时候加一个换行符即可。

测试工具下载地址：

 

附上我的socket客户端代码：

public class QpushClient implements Runnable {    protected static QpushClient mInstance;    protected Handler mHandler;    protected InetSocketAddress mAddress;    protected String TAG = "QpushClient";    private final int TIME_OUT = 5 * 1000;    //巡检周期    private final int CHECK_PERIOD = 2 * 1000;    //连接尝试间隔时间    private final int CONNECT_PERIOD = 30 * 1000;    private final int HEARTBEART_PERIOD = 10 * 1000;    //若连接失败或响应失败，则尝试次数为9，若仍无效，则不再尝试    private final int CONNECT_TRY_TIMES = 9;    //连接尝试次数    private int mConnectCount;    Socket mClientSocket;    String mHost;    int mPort;    //设置是否去读取数据    boolean isStartRecieveMsg = false;    //开启心跳检测    boolean isKeepHeartBeat = false;    private QpushClient(Handler handler) {        mHandler = handler;    }    public static QpushClient getInstance(Handler handler) {        if (mInstance == null) {            mInstance = new QpushClient(handler);        }        return mInstance;    }    public void init(String host, int port) {        mHost = host;        mPort = port;        new Thread(this).start();        isStartRecieveMsg = true;        isKeepHeartBeat = true;    }    @Override    public void run() {        mAddress = new InetSocketAddress(mHost, mPort);        if (mClientSocket == null) {            mClientSocket = new Socket();        }        //尝试连接，若未连接，则设置尝试次数        while (!mClientSocket.isConnected() && mConnectCount < CONNECT_TRY_TIMES) {            connect();            if (!mClientSocket.isConnected()) {                mConnectCount++;                sleep(CONNECT_PERIOD);            } else {                mConnectCount = 0;//连接上，则恢复置0            }        }        if (mClientSocket.isConnected()) {            //开始登陆            sendMsg("login");            recvMsg();            keepHeartBeat();        }    }    private void connect() {        try {            mClientSocket.connect(mAddress);        } catch (IOException e) {            e.printStackTrace();            Log.e(TAG, "mClientSocket.connect fail " + e.getMessage());        }    }    /**     * 心跳维护     */    private void keepHeartBeat() {        //设置心跳频率，启动心跳        while(isKeepHeartBeat){            sendMsg("我是心跳包");            sleep(HEARTBEART_PERIOD);        }    }    BufferedWriter mWriter;    BufferedReader mReader;    /**     * 不断的检测是否有服务器推送的数据过来     */    public void recvMsg() {        while (mClientSocket != null && mClientSocket.isConnected() && !mClientSocket.isClosed()) {            try {                mReader = new BufferedReader(new InputStreamReader(mClientSocket.getInputStream(), "utf-8"));                while (isStartRecieveMsg) {                    Log.e(TAG, "recvMsg5");                    if (mReader.ready()) {                        Log.e(TAG, "recvMsg6");                            /*读取一行字符串，读取的内容来自于客户机                            reader.readLine()方法是一个阻塞方法，                            从调用这个方法开始，该线程会一直处于阻塞状态，                            直到接收到新的消息，代码才会往下走*/                        String data = mReader.readLine();                        Log.e(TAG,"isStartRecieveMsg data="+data);                        //handler发送消息，在handleMessage()方法中接收                        handlerMsg(data);                    }                    Thread.sleep(200);                }            } catch (InterruptedException ex) {                ex.printStackTrace();            } catch (IOException e) {                e.printStackTrace();            } catch (Exception ex) {                ex.printStackTrace();            }            sleep(200);        }        if (!mClientSocket.isConnected()) {            connect();            recvMsg();        }        sleep(CHECK_PERIOD);    }    private void sleep(long sleepTime) {        try {            Thread.sleep(sleepTime);        } catch (InterruptedException e) {            e.printStackTrace();        }    }    /**     * 销毁socket     */    public void onDestory() {        if (mClientSocket != null) {            try {                mClientSocket.close();            } catch (IOException e) {                e.printStackTrace();            }            mClientSocket = null;        }    }    public void sendMsg(String message) {        PrintWriter writer;        try {            writer = new PrintWriter(new OutputStreamWriter(                    mClientSocket.getOutputStream()), true);            writer.println(message);        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    /*     * Ready for use.     */    public void close() {        try {            if (mClientSocket != null && !mClientSocket.isClosed())                mClientSocket.close();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    /**     * 处理服务器返回过来的消息     * @param data     */    private void handlerMsg(String data){        //对数据进行protobuf解析        //消息类型：1=登录成功、2=心跳检测、3=推送消息        int msgType=1;        switch(msgType){            case 1:                sendMsg("success");                break;            case 2:                sendMsg("success");                break;            case 3: //需要通知service                sendMsg("success");                mHandler.obtainMessage(QpushService.PUSH_TYPE_DATA, data).sendToTarget();                break;        }    }}