DWR（Direct Web Remoting）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,可以帮助开发人员开发包含AJAX技术的网站.它可以允许在里的代码使用运行在上的JAVA函数,就像它就在浏览器里一样。

         

以下模拟一个简单的dwr入门案例，重点理解dwr是如何跟java后台服务器打交道的

模拟效果如下

该功能说明了dwr是怎么跟后台服务器打交道的

模拟从服务器加载下拉列表数据

模拟保存功能

模拟查询功能

                  

接下来为dwr+spring集成步骤：

1、新建一个web工程，导入dwr+spring所需jar，如下图

              

目录结构图

              

修改web.xml

       
       
        
        
        
         contextConfigLocation
         
        
         classpath:resource/app*.xml
         
        
        
        
         org.springframework.web.context.ContextLoaderListener
         
        
        
        
        
         dwrServlet
         
        
         org.directwebremoting.servlet.DwrServlet
         
         
         
         
          config
          
          
         
           /WEB-INF/classes/config/dwr.xml                
          
         
         
         
          debug
          
         
          true
          
         
        
        
        
         dwrServlet
         
        
         /dwr/*
             
        
      

              

新建实体类Dept

package entity; publicclass Dept {
    private Long id; private String name; public Dept() {
        } public Dept(Long id, String name) {
    this.id = id; this.name = name;     } public Long getId() {
    return id;     } publicvoid setId(Long id) {
    this.id = id;     } public String getName() {
    return name;     } publicvoid setName(String name) {
    this.name = name;     } }

            

新建业务逻辑类

 DeptServices类

package services; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import entity.Dept; @SuppressWarnings("unchecked") publicclass DeptServices {
    public List findDept() {
    thrownew RuntimeException("查找失败!");     } publicvoid deleteDept(Long id) {
            System.out.println("Delete dept "+ id);     } public List getDeptsForPo() {
            List depts =new ArrayList();         depts.add(new Dept(1l, "教质部"));         depts.add(new Dept(2l, "学术部"));         depts.add(new Dept(3l, "就业部"));         depts.add(new Dept(4l, "咨询部")); return depts;     } publicvoid saveDept(List
      
        depts) {
    // System.out.println(dept.getId() + ":" + dept.getName());         System.out.println(depts);     } public List getDepts() {
            List depts =new ArrayList();         Map map =new HashMap();         map.put("id", "01");         map.put("name", "教质部");         depts.add(map);         map =new HashMap();         map.put("id", "02");         map.put("name", "学术部");         depts.add(map);         map =new HashMap();         map.put("id", "03");         map.put("name", "就业部");         depts.add(map);         map =new HashMap();         map.put("id", "04");         map.put("name", "咨询部");         depts.add(map); try {
                Thread.sleep(1000);         } catch (InterruptedException e) {
                e.printStackTrace();         } return depts;     } }
      

                

HelloServices类

package services; /**  * @author dlwu  * */ publicclass HelloServices {
    public String sayHello(String name){
            System.out.println("Hello now!"); return"Hello "+ name +"!";     } }

             

LoginService类

package services; import org.directwebremoting.WebContext; import org.directwebremoting.WebContextFactory; publicclass LoginService {
    publicvoid checkUserLogin(String userid, String pwd){
            WebContext ctx = WebContextFactory.get();         ctx.getSession().setAttribute("userid", userid);     } public String getLoginUser(){
            WebContext ctx = WebContextFactory.get(); return (String)ctx.getSession().getAttribute("userid");     } }

            

配置applicationContext.xml

             

配置dwr.xml,dwr.xml是前台js跟java服务器沟通的桥梁

             

页面

hello.jsp页面

<%@ page language="java"import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>      
       
       
          
       
        
            
      
    

               

dept.jsp页面

<%@ page language="java"import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>      
       
       
          
       
        
              
      
       ID:       Name: