Java怎么让socket服务一直运行？

用while（）循环不断接受和发送，要用线程啊记得。。。然后添加事件响应 关闭程序就调用socket.close（）

非守护线程

基本上来说的，socker连接，服务始终运行，是都通while(true)

不管是BIO还是NIO，其实都是通过轮训的方式来实现socket服务的。下面几个demo或许有助于你：

• BIO

public class BIODemo {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket();
        serverSocket.bind(new InetSocketAddress("0.0.0.0", 8888), 50);
        Socket socket;
        while ((socket = serverSocket.accept()) != null) {
            InputStream is = socket.getInputStream();
            byte[] data = new byte[1024];
            is.read(data);

            System.out.println(new String(data, UTF_8));
            OutputStream out = socket.getOutputStream();
            out.write(data);
            socket.close();
        }
    }
}

• NIO

public class NIODemo {
    public static void main(String[] args) throws IOException {
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress("0.0.0.0", 8888), 50);
        serverSocketChannel.configureBlocking(false);
        Selector selector = Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        while (true) {
            selector.select();
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                SelectionKey key = iterator.next();
                if (!key.isValid()) {
                    continue;
                }

                if (key.isAcceptable()) {
                    ServerSocketChannel serverChannel = (ServerSocketChannel) key.channel();
                    SocketChannel clientChannel = serverChannel.accept();
                    clientChannel.configureBlocking(false);
                    clientChannel.register(selector, SelectionKey.OP_READ);
                } else if (key.isReadable()) {
                    ByteBuffer buffer = ByteBuffer.wrap(new byte[1024]);
                    SocketChannel clientChannel = (SocketChannel) key.channel();
                    int read = clientChannel.read(buffer);

                    if (read == -1) {
                        key.cancel();
                        clientChannel.close();
                    } else {
                        buffer.flip();
                        clientChannel.write(buffer);
                    }
                }
            }
            iterator.remove();
        }
    }
}

如果你需要更详细的更深入的了解，可以参考我的这篇文章 JAVA中BIO、NIO、AIO的分析理解 https://developer.aliyun.com/article/726698?spm=a2c6h.13148508.0.0.1d844f0eaWNdWj

不断的轮询请求，通过accept（）方法实现。

while(true){
Socket socket=serverSocket.accept();
new Thread(new MyRuns(socket)).start();
}

心跳

最简单的BIO服务端的话,demo 通常是写成 while(true)的

可以使用多线程保活线程。