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Socket断开不报错(Java)

网上看了很多关于 Socket 的 Demo，用起来挺好用也简单，不过都在断开连接时，都没有做好相关处理，导致每次主动断开时，会报错

如：

java.net.SocketException: Socket closed
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
    at java.net.SocketInputStream.read(SocketInputStream.java:171)
    at java.net.SocketInputStream.read(SocketInputStream.java:141)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.BufferedReader.fill(BufferedReader.java:161)
    at java.io.BufferedReader.readLine(BufferedReader.java:324)
    at java.io.BufferedReader.readLine(BufferedReader.java:389)
    at com.idea_a.its.robot.http.SocketUtil.connectionData(SocketUtil.java:136)
    at com.idea_a.its.robot.TryBServer$1$1.success(TryBServer.java:38)
    at com.idea_a.its.robot.http.SocketUtil.connectSocket(SocketUtil.java:55)
    at com.idea_a.its.robot.TryBServer$1.run(TryBServer.java:34)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

 

具体原因是在执行 socket.close()；的同时，相关的 BufferedReader 还在等待接收数据。

所以在断开之前需要执行相关输入输出的关闭动作。

socket.shutdownInput();
socket.shutdownOutput();
并需要确保都关闭后（socket.isInputShutdown()socket.isOutputShutdown()），
才进行 BufferedReader 的关闭，
最终才是关闭 socket； 
代码如下:
    /**
     * 关闭
     */
    public void close() throws IOException {
        if (socket == null) return;

    socket.shutdownInput();
    socket.shutdownOutput();

    </span><span style="color: rgba(0, 0, 255, 1)">do</span><span style="color: rgba(0, 0, 0, 1)"> {
        </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> {
            Thread.sleep(</span>1<span style="color: rgba(0, 0, 0, 1)">);
        } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (InterruptedException e) {
            e.printStackTrace();
        }
    } </span><span style="color: rgba(0, 0, 255, 1)">while</span> (!socket.isInputShutdown() || !<span style="color: rgba(0, 0, 0, 1)">socket.isOutputShutdown());

    br.close();
    socket.close();
    socket </span>= <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
}</span></pre>

 


 就以客户端为例：完整代码如下（根据需要自行增减）：package com.bug01.trysocket;import java.io.BufferedReader;

 

import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;

public class SocketClientUtil implements Closeable {
private static final String ADDRESS = "127.0.0.1";
private static final String PORT = "6666";
private Socket socket = null;
private BufferedReader br;
private static SocketClientUtil instance = null;


</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 此处使用单例模式</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span><span style="color: rgba(0, 0, 0, 1)"> SocketClientUtil getInstance() {
    </span><span style="color: rgba(0, 0, 255, 1)">if</span> (instance == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
        </span><span style="color: rgba(0, 0, 255, 1)">synchronized</span> (SocketClientUtil.<span style="color: rgba(0, 0, 255, 1)">class</span><span style="color: rgba(0, 0, 0, 1)">) {
            </span><span style="color: rgba(0, 0, 255, 1)">if</span> (instance == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
                instance </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> SocketClientUtil();
            }
        }
    }
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> instance;
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 连接socket
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span> connectSocket(SocketConnCallBack back) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> IOException {
    </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> {
        socket </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Socket(ADDRESS, Integer.parseInt(PORT));
        back.success();
    } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (IOException e) {
        e.printStackTrace();
        back.failure();
        socket </span>= <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (Exception e) {
        e.printStackTrace();
        back.failure();
    }
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 发送数据
 *
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> message
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span> sendData(String message) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> IOException {
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">判定是否socket已链接，如果未链接则尝试链接。</span>
    <span style="color: rgba(0, 0, 255, 1)">if</span> (socket == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
        connectSocket(</span><span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> SocketConnCallBack() {
            @Override
            </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> success() {

            }

            @Override
            </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> failure() {

            }
        });
    }
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">如果尝试链接失败，则上报异常。</span>
    <span style="color: rgba(0, 0, 255, 1)">if</span> (socket == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
        </span><span style="color: rgba(0, 0, 255, 1)">throw</span> <span style="color: rgba(0, 0, 255, 1)">new</span> IOException("Socket Connect to Server Error."<span style="color: rgba(0, 0, 0, 1)">);
    }

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">输出流</span>
    OutputStream os =<span style="color: rgba(0, 0, 0, 1)"> socket.getOutputStream();
    PrintWriter pw </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> PrintWriter(os);
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">向服务端写入数据</span>



        pw.println(message);
pw.flush();
}


</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 接受数据
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span> SetListener(SocketCallBack back) <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> IOException {
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">输入流</span>
    InputStream is =<span style="color: rgba(0, 0, 0, 1)"> socket.getInputStream();
    br </span>= <span style="color: rgba(0, 0, 255, 1)">new</span> BufferedReader(<span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> InputStreamReader(is));
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">接收服务器的相应</span>
    String reply = <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    </span><span style="color: rgba(0, 0, 255, 1)">while</span> (!((reply = br.readLine()) == <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">)) {
        back.responseData(reply.trim());
    }
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 关闭
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span><span style="color: rgba(0, 0, 0, 1)">
@Override
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span> close() <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> IOException {
    </span><span style="color: rgba(0, 0, 255, 1)">if</span> (socket == <span style="color: rgba(0, 0, 255, 1)">null</span>) <span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)">;

    socket.shutdownInput();
    socket.shutdownOutput();

    </span><span style="color: rgba(0, 0, 255, 1)">do</span><span style="color: rgba(0, 0, 0, 1)"> {
        </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> {
            Thread.sleep(</span>1<span style="color: rgba(0, 0, 0, 1)">);
        } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (InterruptedException e) {
            e.printStackTrace();
        }
    } </span><span style="color: rgba(0, 0, 255, 1)">while</span> (!socket.isInputShutdown() || !<span style="color: rgba(0, 0, 0, 1)">socket.isOutputShutdown());

    br.close();
    socket.close();
    socket </span>= <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">interface</span><span style="color: rgba(0, 0, 0, 1)"> SocketCallBack {
    </span><span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> responseData(String data);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">interface</span><span style="color: rgba(0, 0, 0, 1)"> SocketConnCallBack {
    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">socket连接成功</span>
    <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> success();

    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">socket链接失败</span>
    <span style="color: rgba(0, 0, 255, 1)">void</span> failure() <span style="color: rgba(0, 0, 255, 1)">throws</span><span style="color: rgba(0, 0, 0, 1)"> IOException;
}



}