Mina's long and short connections

1. Long connection

The two communicating parties maintain a connection state for a long time without disconnecting.

For example, when you log in to QQ, you will connect to the Tencent server. Once the connection is established, it will not be disconnected unless an exception occurs. This method is a long connection.

It consumes IO resources for long connections.

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2. Short connection

The two communicating parties do not maintain a long-term connection state. After a request-response ends, the connection is automatically disconnected.

For example: http protocol, the client initiates an http request, and the server processes the http request. When the server finishes processing, it disconnects the client data after returning it, and needs to re-initiate the next connection request.

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3. Short connection chestnut

Or refer to the previous section"Introduction to Mina""'s chestnut, modify the processor MyServerHandler.java on the Mina server side

 package com.hl.magic.mina.mina1;import org.apache.mina.core.service.IoHandlerAdapter;import org.apache.mina.core.session.IdleStatus;import org.apache.mina.core.session.IoSession;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.util.Date;/*** Custom Mina server session adapter** @Author HL* @Date 2021/10/10 21:06*/public class MyServerHandler extends IoHandlerAdapter {private static final Logger LOGGER = LoggerFactory.getLogger(MyServerHandler.class);/*** create session** @param session session object*/@Overridepublic void sessionCreated(IoSession session) throws Exception {LOGGER.debug("sessionCreated");}/*** Open session** @param session session object*/@Overridepublic void sessionOpened(IoSession session) throws Exception {LOGGER.debug("sessionOpened");}/*** close the session** @param session session object*/@Overridepublic void sessionClosed(IoSession session) throws Exception {LOGGER.debug("sessionClosed");}/*** Session idle** @param session session object* @param status session status*/@Overridepublic void sessionIdle(IoSession session, IdleStatus status) {LOGGER.debug("IDLE: [{}]", session.getIdleCount(status));}/*** When the connection is abnormal** @param session session object*/@Overridepublic void exceptionCaught(IoSession session, Throwable cause) {LOGGER.debug("exceptionCaught");}/*** receive messages** @param session session object* @param message message body*/@Overridepublic void messageReceived(IoSession session, Object message) {String msg = (String) message;LOGGER.debug("Data received by server: [{}]", msg);//Long connection mode monitoring, if you want to change to short connection, comment the connection disconnection mode below, and disconnect in the messageSent method// if (msg.trim().equalsIgnoreCase("quit")) {// session.closeNow();// return;// }Date date = new Date();session.write("message received, time: " + date);}/*** Occurrence message** @param session session object* @param message message body*/@Overridepublic void messageSent(IoSession session, Object message) {LOGGER.debug("messageSent...");// Short connection method, automatically disconnect after sending the messagesession.closeNow();}}

Run Mina server program MyServer.java class

Run CMD, enter telnet 127.0.0.1 54321 in the window to establish a connection with the server

Then send the data "ww", you can see that the server will automatically disconnect after receiving the data and giving a response.