dwr+spring集成

dwr+spring集成

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.它可以允许在浏览器里的代码使用运行在WEB服务器上的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

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.4" 

    xmlns="http://java.sun.com/xml/ns/j2ee" 

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 

    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <!-- Spring上下文 -->

    <context-param>

        <param-name>contextConfigLocation</param-name>

        <param-value>classpath:resource/app*.xml</param-value>

    </context-param>

    <listener>

        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

    </listener>

    <!-- 配置DWR前端控制器 -->

    <servlet>

        <servlet-name>dwrServlet</servlet-name>

        <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>

        <!-- 指定配置文件 -->

        <init-param>

            <param-name>config</param-name>

            <!-- 如果有多个用","分开 -->

            <param-value>

                /WEB-INF/classes/config/dwr.xml                

            </param-value>

        </init-param>

        <init-param>

            <param-name>debug</param-name>

            <param-value>true</param-value>

        </init-param>

    </servlet>

    <servlet-mapping>

        <servlet-name>dwrServlet</servlet-name>

        <url-pattern>/dwr/*</url-pattern>

    </servlet-mapping>

</web-app>

新建实体类Dept

package entity;

public class 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;

    }

    public void setId(Long id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void 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")

public class DeptServices {

    public List findDept() {

        throw new RuntimeException("查找失败!");

    }

    public void 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;

    }

    

    public void saveDept(List<Dept> 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

 *

 */

public class 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;

public class LoginService {

    public void 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

<?xml version="1.0" encoding="UTF-8"?>

<!--

    配置系统基础环境

 -->

<beans

    xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"

    >            

    <bean id="deptServices" class="services.DeptServices"></bean>

    <bean id="loginSrv" class="services.LoginService"></bean>

</beans>

配置dwr.xml,dwr.xml是前台js跟java服务器沟通的桥梁

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://getahead.org/dwr/dwr20.dtd">

<!-- 通用dwr配置 -->

<dwr>

    <allow>

        <!-- 建立JS对象，将目标对象的方法转换成JS对象的方法 -->

        <create javascript="helloSrv" creator="new">

            <param name="class" value="services.HelloServices"></param>

        </create>

        <!-- 从Spring中获取Java对象 -->

        <create javascript="deptSrv" creator="spring">

            <param name="beanName" value="deptServices"></param>

            <!-- 禁止执行 -->

            <exclude method="deleteDept" />

        </create>

        <create javascript="loginSrv" creator="spring">

            <param name="beanName" value="loginSrv"></param>

        </create>

        <!-- 指定针对于特定对象的转换器 -->

        <convert match="entity.*" converter="bean"></convert>

        <convert match="java.lang.Throwable" converter="bean">

            <param name="include" value="message"></param>

        </convert>

    </allow>

</dwr>

页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

    <base href="<%=basePath%>">

    

    <title>My JSP 'hello.jsp' starting page</title>

    

    <meta http-equiv="pragma" content="no-cache">

    <meta http-equiv="cache-control" content="no-cache">

    <meta http-equiv="expires" content="0">    

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

    <meta http-equiv="description" content="This is my page">

  </head>

  <!-- 记得引入js，测试地址： http://localhost:8083/dwrweb/dwr/ -->

  <script type="text/javascript" src="dwr/engine.js"></script>

  <script type="text/javascript" src="dwr/interface/helloSrv.js"></script>

  <script type="text/javascript" src="dwr/util.js"></script>

  <script type="text/javascript">

          function hello(){

              //方法一

              //返回处理后的结果信息

            /*var fn = function(result){

                $("msg").innerHTML = result;

            }

            helloSrv.sayHello($("name").value, fn);*/

            

            //方法二

            helloSrv.sayHello($("name").value, function(result){

                $("msg").innerHTML=result;

            });

            

            //方法三

            //使用如下的好处为：不用导入如上三个js        

            //第一个参数: dwr访问路径，在web.xml中配置，如： <url-pattern>/dwr/*</url-pattern>        

            //第二个参数: dwr与java服务器通信变量，在dwr.xml中声明        

            //第三个参数: 服务器方法名

            //第四个参数: 页面请求参数，即服务器方法名得参数

            //第五个参数: 回调函数        

            //dwr.engine._execute("dwr", 'helloSrv', 'sayHello', $("name").value, fn);

            

          }

  </script>

  <body>

      <div id="msg"></div>

    <input type="text" id="name" />

    <input type="button" value="Hello" onclick="hello();" />

  </body>

</html>

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+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

    <base href="<%=basePath%>">

    

    <title>My JSP 'hello.jsp' starting page</title>

    

    <meta http-equiv="pragma" content="no-cache">

    <meta http-equiv="cache-control" content="no-cache">

    <meta http-equiv="expires" content="0">    

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

    <meta http-equiv="description" content="This is my page">

  </head>

  <!-- 记得引入js，测试地址： http://localhost:8083/dwrweb/dwr/ -->

  <script type="text/javascript" src="dwr/engine.js"></script>

  <script type="text/javascript" src="dwr/interface/helloSrv.js"></script>

  <script type="text/javascript" src="dwr/util.js"></script>

  <script type="text/javascript">

          function loadDept(){

              //说明已经加载，不必重新加载

              if($('depts').options.length > 0){

                  return;

              }

              DWRUtil.addOptions('depts', [{id:'',name:'正在下载...'}], 'id', 'name');

              dwr.engine._execute("dwr", 'deptSrv', 'getDepts', function(depts){

                  DWRUtil.removeAllOptions('depts');

                  DWRUtil.addOptions('depts', depts, 'id', 'name');

              });

          }

          function loadDept2(){

              if($('depts2').options.length > 0){

                  return;

              }

              DWRUtil.addOptions('depts2', [{id:'',name:'正在下载...'}], 'id', 'name');

              dwr.engine._execute("dwr", 'deptSrv', 'getDeptsForPo', function(depts){

                  DWRUtil.removeAllOptions('depts2');

                  DWRUtil.addOptions('depts2', depts, 'id', 'name');

              });

          }

          function saveDept(){

              //声明dept对象

              var dept = {

                  id:$("deptid").value, 

                  name:$("deptname").value

              };

              dwr.engine._execute("dwr", 'deptSrv', 'saveDept', [dept], function(){

                  alert('保存成功!');

              });

              

          }

          function find(){

              dwr.engine._execute("dwr", 'deptSrv', 'findDept', {

                  callback:function(results){

                      alert('查询成功!');

                  },

                  errorHandler:function(e){

                      alert("查询失败:" + e);

                  }

              });

              

          }

  </script>

  <body>

      <select id="depts" onclick="loadDept();"></select>

      <select id="depts2" onclick="loadDept2();"></select>

      <hr/>

      ID:<input id="deptid" type="text" size="8"/>

      Name:<input id="deptname" type="text" size="8"/>

      <input value="保存部门" type="button" onclick="saveDept();"/>

      <input value="查找" type="button" onclick="find();"/>

  </body>

</html>

访问路径：

测试路径：http://localhost:8083/dwrweb/dwr/

              http://localhost:8083/dwrweb/hello.jsp

              http://localhost:8083/dwrweb/dept.jsp