客戶(hù)端與服務(wù)器在用websocket通信的時(shí)候，如果客戶(hù)端突然關(guān)閉網(wǎng)絡(luò)或者直接關(guān)機(jī)，此時(shí)路由與服務(wù)器之間的鏈接還存在

在服務(wù)器端輸入查看
netstat -anp | grep 5007
tcp6       0      0 192.168.0.121:5007      119.119.0.0:60944    ESTABLISHED 23585/java

若不給該客戶(hù)端發(fā)信息，除非路由器重啟，否則這個(gè)鏈接會(huì)一直存在，服務(wù)器會(huì)一直認(rèn)為該鏈接存在，后果就是隨著大連無(wú)用的tcp連接積累，服務(wù)器會(huì)報(bào)socket too many open files錯(cuò)誤導(dǎo)致服務(wù)掛掉。

解決方法：

要求websocket客戶(hù)端定期發(fā)送PING，服務(wù)器返回PONG，客戶(hù)端意外斷開(kāi)的時(shí)候服務(wù)器發(fā)現(xiàn)在一段時(shí)間內(nèi)沒(méi)交互信息關(guān)閉該session。

通過(guò)讀spring-websocket\5.3.24的源碼并參考

源碼 springframework\spring-websocket\5.3.24\spring-websocket-5.3.24-sources\org\springframework\web\socket\server\standard\ServletServerContainerFactoryBean.java

/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.socket.server.standard;

import javax.servlet.ServletContext;
import javax.websocket.WebSocketContainer;
import javax.websocket.server.ServerContainer;

import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.context.ServletContextAware;

/**
 * A {@link FactoryBean} for configuring {@link javax.websocket.server.ServerContainer}.
 * Since there is usually only one {@code ServerContainer} instance accessible under a
 * well-known {@code javax.servlet.ServletContext} attribute, simply declaring this
 * FactoryBean and using its setters allows for configuring the {@code ServerContainer}
 * through Spring configuration.
 *
 * <p>This is useful even if the {@code ServerContainer} is not injected into any other
 * bean within the Spring application context. For example, an application can configure
 * a {@link org.springframework.web.socket.server.support.DefaultHandshakeHandler},
 * a {@link org.springframework.web.socket.sockjs.SockJsService}, or
 * {@link ServerEndpointExporter}, and separately declare this FactoryBean in order
 * to customize the properties of the (one and only) {@code ServerContainer} instance.
 *
 * @author Rossen Stoyanchev
 * @author Sam Brannen
 * @since 4.0
 */
public class ServletServerContainerFactoryBean
        implements FactoryBean<WebSocketContainer>, ServletContextAware, InitializingBean {

    @Nullable
    private Long asyncSendTimeout;

    @Nullable
    private Long maxSessionIdleTimeout;

    @Nullable
    private Integer maxTextMessageBufferSize;

    @Nullable
    private Integer maxBinaryMessageBufferSize;

    @Nullable
    private ServletContext servletContext;

    @Nullable
    private ServerContainer serverContainer;


    public void setAsyncSendTimeout(Long timeoutInMillis) {
        this.asyncSendTimeout = timeoutInMillis;
    }

    @Nullable
    public Long getAsyncSendTimeout() {
        return this.asyncSendTimeout;
    }

    public void setMaxSessionIdleTimeout(Long timeoutInMillis) {
        this.maxSessionIdleTimeout = timeoutInMillis;
    }

    @Nullable
    public Long getMaxSessionIdleTimeout() {
        return this.maxSessionIdleTimeout;
    }

    public void setMaxTextMessageBufferSize(Integer bufferSize) {
        this.maxTextMessageBufferSize = bufferSize;
    }

    @Nullable
    public Integer getMaxTextMessageBufferSize() {
        return this.maxTextMessageBufferSize;
    }

    public void setMaxBinaryMessageBufferSize(Integer bufferSize) {
        this.maxBinaryMessageBufferSize = bufferSize;
    }

    @Nullable
    public Integer getMaxBinaryMessageBufferSize() {
        return this.maxBinaryMessageBufferSize;
    }

    @Override
    public void setServletContext(ServletContext servletContext) {
        this.servletContext = servletContext;
    }


    @Override
    public void afterPropertiesSet() {
        Assert.state(this.servletContext != null,
                "A ServletContext is required to access the javax.websocket.server.ServerContainer instance");
        this.serverContainer = (ServerContainer) this.servletContext.getAttribute(
                "javax.websocket.server.ServerContainer");
        Assert.state(this.serverContainer != null,
                "Attribute 'javax.websocket.server.ServerContainer' not found in ServletContext");

        if (this.asyncSendTimeout != null) {
            this.serverContainer.setAsyncSendTimeout(this.asyncSendTimeout);
        }
        if (this.maxSessionIdleTimeout != null) {
            this.serverContainer.setDefaultMaxSessionIdleTimeout(this.maxSessionIdleTimeout);
        }
        if (this.maxTextMessageBufferSize != null) {
            this.serverContainer.setDefaultMaxTextMessageBufferSize(this.maxTextMessageBufferSize);
        }
        if (this.maxBinaryMessageBufferSize != null) {
            this.serverContainer.setDefaultMaxBinaryMessageBufferSize(this.maxBinaryMessageBufferSize);
        }
    }


    @Override
    @Nullable
    public ServerContainer getObject() {
        return this.serverContainer;
    }

    @Override
    public Class<?> getObjectType() {
        return (this.serverContainer != null ? this.serverContainer.getClass() : ServerContainer.class);
    }

    @Override
    public boolean isSingleton() {
        return true;
    }

}

https://docs.spring.io/spring-framework/docs/5.3.24/reference/html/web.html#websocket-intro-architecture

方法setMaxSessionIdleTimeout設(shè)置session超時(shí)時(shí)間。文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-501838.html

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
import org.springframework.web.socket.server.HandshakeInterceptor;
import org.springframework.web.socket.server.standard.ServletServerContainerFactoryBean;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {


   
    @Bean
    public ServletServerContainerFactoryBean createWebSocketContainer() {
        ServletServerContainerFactoryBean container = new ServletServerContainerFactoryBean();
      
        container.setMaxTextMessageBufferSize(512000);
        container.setMaxBinaryMessageBufferSize(512000);
        container.setMaxSessionIdleTimeout(5 * 1000L);
        return container;
    }
}