Socket的超时时间

朱雀 2022-11-11 13:17 252阅读 0赞

Socket中会有两种超时时间，分别为：`socket.connect(endpoint,3000);`和`socket.setSoTimeout(3000);`此两种超时时间有和区别呢？

### socket.connect(endpoint,3000);连接的超时时间 ###

*  尝试3秒，三秒连不上报错。（不指定的话默认是无限，但是也会有个超时时间，不会一直等下去。）

// 客户端
    public class ClientSocket { 
        public static void main(String[] args) throws IOException { 
    
            SocketAddress endpoint = new InetSocketAddress("182.207.155.166", 11111);
           //SocketAddress endpoint = new InetSocketAddress("127.0.0.1", 11111);
            Socket socket = new Socket();
            socket.connect(endpoint,3000);
            // socket.setSoTimeout(3000);
            OutputStream outputStream = socket.getOutputStream();
            outputStream.write("你好,你能收到我的消息吗?".getBytes());
            InputStream inputStream = socket.getInputStream();
            byte[] bytes = new byte[1024];
            int read = inputStream.read(bytes);
            String str = new String(bytes, 0, read);
            System.out.println(str);
            outputStream.close();
            socket.close();
        }
    }
    //服务器端
    public class ServerSocketTest { 
        public static void main(String[] args) throws IOException, InterruptedException { 
            ServerSocket serverSocket = new ServerSocket(11111);
            while (true) { 
                Socket accept = serverSocket.accept();
                InputStream inputStream = accept.getInputStream();
                byte[] bytes =new byte[1024];
                int read = inputStream.read(bytes);
                System.out.println(new String(bytes,0,read));
                Thread.sleep(4000);
                OutputStream outputStream = accept.getOutputStream();
                String str = "{"+new String(bytes, 0, read)+"}<---我能收到";
                outputStream.write(str.getBytes());
            }
        }
    }

**执行结果分析：**

*  此时客户端是无法连接到（“182.107.155.166”, 11111）该IP端口为不存在的。
 *  此时设置超时时间为客户端等待连接服务端的时间，3秒内连接不上报错。

> Exception in thread “main” java.net.SocketTimeoutException: connect timed out  
> at java.net.PlainSocketImpl.socketConnect(Native Method)  
> at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)  
> at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)  
> at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)  
> at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)  
> at java.net.Socket.connect(Socket.java:589)  
> at com.weidd.best.sockettest.ClientSocket.main(ClientSocket.java:22)

### socket.setSoTimeout(3000);设置接收响应的时间 ###

*  等待3秒，3秒内服务端未响应，报错。

public class ClientSocket { 
        public static void main(String[] args) throws IOException { 
    
       // SocketAddress endpoint = new InetSocketAddress("182.107.155.166", 11111);
            SocketAddress endpoint = new InetSocketAddress("127.0.0.1", 11111);
            Socket socket = new Socket();
            socket.connect(endpoint,3000);
            socket.setSoTimeout(3000);
            OutputStream outputStream = socket.getOutputStream();
            outputStream.write("你好,你能收到我的消息吗?".getBytes());
            InputStream inputStream = socket.getInputStream();
            byte[] bytes = new byte[1024];
            int read = inputStream.read(bytes);
            String str = new String(bytes, 0, read);
            System.out.println(str);
            outputStream.close();
            socket.close();
        }
    }

**执行结果分析：**

*  此时服务端也启动，但是休眠4秒。当客户端连上服务端后，3秒内得不到响应则报错。

> Exception in thread “main” java.net.SocketTimeoutException: Read timed out  
> 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 java.net.SocketInputStream.read(SocketInputStream.java:127)  
> at com.weidd.best.sockettest.ClientSocket.main(ClientSocket.java:28)