由于本人在实际项目开发中有涉及到流程跑批，每个节点顺序点击执行后必须刷新页面才能看到状态是否变更。从客户体验上来说，这点是非常差的，于是想到dwr和websocket实现实时消息推送浏览器，前者是一个用于改善web页面与Java类交互的远程服务器端Ajax开源框架，它可以允许在浏览器里的代码使用运行在WEB服务器上的JAVA方法，就像它就在浏览器里一样，但存在一定的java代码泄露风险，而后者是一种网络双工通讯TCP协议，长连接，需要客户端发起连接。两者实现起来都是相对比较简单的，下面来简单实现下dwr！

实现步骤如下：

1、maven引jar   

       
     
      org.directwebremoting
        
     
      dwr
        
     
      3.0.2-RELEASE
     
    

2、dwr无xml配置部分

package com.paic.commcc.support.dwr;import org.directwebremoting.Container;import org.directwebremoting.create.NewCreator;import org.directwebremoting.extend.Configurator;import org.directwebremoting.extend.CreatorManager;/** * @author  * @Package com.paic.commcc.support.dwr * @Description: dwr的xml配置 * @date 2018/12/11 19:19 */public class DwrXml implements Configurator {    @Override    public void configure(Container container) {        CreatorManager creatorManager = container.getBean(CreatorManager.class);        NewCreator creator = new NewCreator();        creator.setClass("com.paic.commcc.support.dwr.DwrPush");        creator.setJavascript("DwrPush");        creatorManager.addCreator(creator);    }}

3、dwr核心配置，注意标色代码部分是第2点的配置类路径

package com.paic.commcc.support.dwr;import org.directwebremoting.servlet.DwrListener;import org.directwebremoting.servlet.DwrServlet;import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;import org.springframework.boot.web.servlet.ServletRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import java.util.HashMap;import java.util.Map;/** * @author  * @Package com.paic.commcc.support.dwr * @Description: 远程服务端ajax * @date 2018/12/11 19:17 */@Configurationpublic class DwrConfig {    @Bean    public ServletRegistrationBean dwr() {        ServletRegistrationBean servlet = new ServletRegistrationBean(new DwrServlet(), "/dwr/*");        Map
    
      initParam = new HashMap<>();        initParam.put("crossDomainSessionSecurity", "false");        initParam.put("allowScriptTagRemoting", "true");        initParam.put("classes", "java.lang.Object");        initParam.put("activeReverseAjaxEnabled", "true");        initParam.put("initApplicationScopeCreatorsAtStartup", "true");        initParam.put("maxWaitAfterWrite", "60000");        initParam.put("debug", "true");        initParam.put("logLevel", "WARN");        //自定义配置，org.directwebremoting.impl.StartupUtil#configureFromInitParams name.equals("customConfigurator")        //DwrServlet#init 初始化this.container        initParam.put("customConfigurator", "com.paic.commcc.support.dwr.DwrXml");        servlet.setInitParameters(initParam);        return servlet;    }    @Bean    public ServletListenerRegistrationBean dwrListener() {        return new ServletListenerRegistrationBean(new DwrListener());    }}
    

4、dwr推送消息类

package com.paic.commcc.support.dwr;import org.directwebremoting.Browser;import org.directwebremoting.ScriptSession;import org.directwebremoting.ScriptSessionFilter;import org.directwebremoting.ScriptSessions;/** * @author  * @Package com.paic.commcc.support.dwr * @Description: dwr推送消息类 * @date 2018/12/11 19:23 */public class DwrPush {    public static void init(String msg) {        DwrPush.sendMsgToPage("/dwr.html", msg);    }    /**     * @Description: 推送消息至页面，默认onDwrData函数     * @Param: [html, msg]     * @return: void     * @Author:      * @Date: 2018/12/12     */    public static void sendMsgToPage(final String html, final String msg) {        sendMsgToPage(html, "onDwrData", msg);    }    public static void sendMsgToPage(final String html, final String function, final String msg) {        Browser.withPage(html, new Runnable() {            public void run() {                ScriptSessions.addFunctionCall(function, msg);            }        });    }    public static void sendMsgWithAllSessions(final String msg) {        Browser.withAllSessions(new Runnable() {            public void run() {                ScriptSessions.addFunctionCall("onDwrData", msg);            }        });    }    public static void sendMsgWithFilter(final String msg) {        Browser.withAllSessionsFiltered(new ScriptSessionFilter() {            @Override            public boolean match(ScriptSession scriptSession) {                // 可以在这里做一些session过滤                return true;            }        }, new Runnable() {            public void run() {                ScriptSessions.addFunctionCall("onDwrData", msg);            }        });    }}

5、dwr.html页面放static目录下，3个js，其中DwrPush.js的名字跟推送消息类一致，其他两个为框架本身的，必须要引用

                    dwr html

然后就可以实现后台有节点状态变更时，调用dwr消息推送类刷新浏览器节点状态了，怎么去刷新就看具体实现。

希望对你有所帮助，谢谢~