// server端
public class SocketServer {
  public static void main(String[] args) throws Exception {
    ServerSocket server = new ServerSocket(8080);
    
    // 阻塞等待连接
    Socket socket = server.accept();

    // 从socket中获取输入流，并建立缓冲区进行读取
    InputStream inputStream = socket.getInputStream();
    byte[] bytes = new byte[1024];
    int len;
    StringBuilder sb = new StringBuilder();
    while ((len = inputStream.read(bytes)) != -1) {
      sb.append(new String(bytes, 0, len,"UTF-8"));
    }
    System.out.println("Received: " + sb);
    OutputStream outputStream = socket.getOutputStream();
    outputStream.write("hello client".getBytes("UTF-8"));
    outputStream.flush();

    // 关闭流&连接
    inputStream.close();
    outputStream.close();
    socket.close();
    server.close();
  }
}
// client 端
public class SocketClient {
  public static void main(String args[]) throws Exception {
    Socket socket = new Socket("127.0.0.1", 8080);
    // 建立连接后获得输出流
    OutputStream outputStream = socket.getOutputStream();
    String message="hello server";
    outputStream.write(message.getBytes("UTF-8"));
    //通知server消息发送完成
    socket.shutdownOutput();
    
    // 读取消息
    InputStream inputStream = socket.getInputStream();
    byte[] bytes = new byte[1024];
    int len;
    StringBuilder sb = new StringBuilder();
    while ((len = inputStream.read(bytes)) != -1) {
      sb.append(new String(bytes, 0, len,"UTF-8"));
    }
    System.out.println("Received: " + sb);

    // 关闭流&连接
    inputStream.close();
    outputStream.close();
    socket.close();
  }
}