我正在尝试编写我的第一个套接字服务器,所以我决定从一个非常简单的事情开始,只是为了计算流程:)我正在编写一个简单的

java echo服务器,但问题是(出于某种原因？！ )我没有在客户端获得服务器响应,但是在服务器中收到了请求.

package poc.client;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.net.Socket;

public class Client {

public static void main(String[] args) {

try {

final Socket socket = new Socket((String) null, 50000);

final BufferedReader reader = new BufferedReader(

new InputStreamReader(socket.getInputStream()));

final PrintWriter writer = new PrintWriter(

socket.getOutputStream(), true);

writer.println("ala bala\r\n");

writer.flush();

writer.close();

System.out.println(reader.readLine());

System.out.flush();

} catch (Exception ex) {

Logger.getAnonymouseLogger().throwing(TAG, "main", ex);

}

}

}

而服务器部分是

package poc.server;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.net.ServerSocket;

import java.net.Socket;

public class Server {

/**

* debugging purposes only

*/

@SuppressWarnings("unused")

private static final String TAG = Server.class.getSimpleName();

public static void main(String[] args) {

try {

final ServerSocket socket = new ServerSocket(50000);

while (true) {

final Socket clientSocket = socket.accept();

final BufferedReader reader = new BufferedReader(

new InputStreamReader(clientSocket.getInputStream()));

final PrintWriter writer = new PrintWriter(clientSocket

.getOutputStream(), true);

writer.println(reader.readLine());

writer.flush();

writer.close();

}

} catch (IOException e) {

Logger.getAnonymouseLogger().throwins(TAG, "main",ex);

}

}

}

我阅读了所有的Oracle基本套接字教程/等,但我无法弄清楚是什么问题 – 我已成功写入服务器套接字但我似乎无法得到响应.

最佳答案 在从套接字读取之前不要关闭写入器.以下代码有效

final Socket socket = new Socket((String) null, 50000);

final BufferedReader reader = new BufferedReader(

new InputStreamReader(socket.getInputStream()));

final PrintWriter writer = new PrintWriter(

socket.getOutputStream(), true);

writer.println("ala bala\r\n");

System.out.println(reader.readLine());

//writer.flush();

writer.close();

根据close()方法的javadoc：

Closes the stream and releases any system resources associated with

it. Closing a previously closed stream has no effect.

看起来如果关闭流,底层套接字也会关闭.您可以通过在当前代码中打印堆栈跟踪来验证这一点.它给出了java.net.SocketException：socket关闭错误.