先上效果图

SocketCommunication.gif

Demo说明

有三个模拟器，通过Socket，将信息相互发送到对方的设备上。其中的认证客户端是指将此客户端的信息传到服务端，以便在客户端一对一发送消息时，服务端可以找到相应的设备。

定义客户端代码

public class ClientConnector {

    private Socket mClient;
    /**
     * 服务端的ip
     */
    private String mDstName;
    /**
     * 服务端端口号
     */
    private int mDesPort;

    private ConnectLinstener mListener;


    public ClientConnector(String dstName, int dstPort) {
        this.mDstName = dstName;
        this.mDesPort = dstPort;
    }

    /**
     * 与服务端进行连接
     *
     * @throws IOException
     */
    public void connect() throws IOException {
        if (mClient == null) {
            mClient = new Socket(mDstName, mDesPort);
        }

        //获取其他客户端发送过来的数据
        InputStream inputStream = mClient.getInputStream();
        byte[] buffer = new byte[1024];
        int len = -1;
        while ((len = inputStream.read(buffer)) != -1) {
            String data = new String(buffer, 0, len);

            //通过回调接口将获取到的数据推送出去
            if (mListener != null) {
                mListener.onReceiveData(data);
            }
        }
    }

    /**
     * 认证方法，这个方法是用来进行客户端一对一发送消息的
     * 在实际项目中进行即时通讯时都需要进行登录，这里就是
     * 模拟客户端的账号
     *
     * @param authName
     */
    public void auth(String authName) throws IOException {
        if (mClient != null) {
            //将客户端账号发送给服务端，让服务端保存
            OutputStream outputStream = mClient.getOutputStream();
            //模拟认证格式，以#开头
            outputStream.write(("#" + authName).getBytes());
        }
    }

    /**
     * 将数据发送给指定的接收者
     *
     * @param receiver 信息接数者
     * @param data     需要发送的内容
     */
    public void send(String receiver, String data) throws IOException {
        OutputStream outputStream = mClient.getOutputStream();
        //模拟内容格式：receiver+  # + content
        outputStream.write((receiver + "#" + data).getBytes());
    }

    /**
     * 断开连接
     *
     * @throws IOException
     */
    public void disconnect() throws IOException {
        if (mClient != null) {
            mClient.close();
            mClient = null;
        }
    }


    public void setOnConnectLinstener(ConnectLinstener linstener) {
        this.mListener = linstener;
    }

    /**
     * 数据接收回调接口
     */
    public interface ConnectLinstener {
        void onReceiveData(String data);
    }
}

定义服务端代码

public class SocketServer {

    /**
     * 用来保存不同的客户端
     */
    private static Map<String, Socket> mClients = new LinkedHashMap<>();

    public static void main(String[] args) {

        int port = 9999;
        try {
            //创建服务器
            ServerSocket serverSocket = new ServerSocket(port);
            while (true) {
                //获取客户端的连接
                final Socket socket = serverSocket.accept();

                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            //读取从客户端发送过来的数据
                            InputStream inputStream = socket.getInputStream();
                            byte[] buffer = new byte[1024];
                            int len = -1;
                            while ((len = inputStream.read(buffer)) != -1) {
                                String data = new String(buffer, 0, len);

                                //先认证客户端
                                if (data.startsWith("#")) {
                                    mClients.put(data, socket);
                                } else {
                                    //将数据发送给指定的客户端
                                    String[] split = data.split("#");
                                    Socket c = mClients.get("#" + split[0]);
                                    OutputStream outputStream = c.getOutputStream();
                                    outputStream.write(split[1].getBytes());

                                }
                            }
                        } catch (IOException e) {
                            e.printStackTrace();
                        }


                    }
                }).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

完整的demo