Dwr级联的小例子

1.引入DWR包

2.配置web.xml文件

<!-- DWR配置 -->
	<servlet>
		<servlet-name>dwr-invoker</servlet-name>
		<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
		<init-param>
			<param-name>debug</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>crossDomainSessionSecurity</param-name>
			<param-value>false</param-value>
		</init-param>
	</servlet>
	<servlet-mapping>
		<servlet-name>dwr-invoker</servlet-name>
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>
	<!-- DWR配置结束 -->

3.WEB-INFO下新建dwr.

xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">

<dwr>
	<allow>
		<!--	测试DWR配置开始	-->
		<convert converter="bean" match="com.estone.www.bjkpcg.manage.ztest.Per"></convert>
		<create creator="new" javascript="service">
			<param name="class" value="com.estone.www.bjkpcg.manage.ztest.HelloWorld"/>
		</create>
		<!--	测试DWR配置结束	-->
		
		<!--批次实体配置-->
		<convert converter="bean" match="com.estone.www.bjkpcg.manage.project.vo.TblCgBatch"></convert>
		
		<convert converter="bean" match="com.estone.www.bjkpcg.manage.production.vo.TblCgProductionType"></convert>
		
		<!--项目类别配置-->
		<create creator="new" javascript="dwrMethod">
			<param name="class" value="com.estone.www.bjkpcg.util.DwrMethod"/>
		</create>
		
		<!--项目类型实体配置-->
		<convert converter="bean" match="com.estone.www.bjkpcg.manage.project.vo.TblCgProjectType"></convert>
		
		<!--项目信息添加配置-->
		<create creator="new" javascript="projectDwr">
			<param name="class" value="com.estone.www.bjkpcg.network.project.dwr.ProjectDwr"/>
		</create>
	</allow>
</dwr>

4.Dwr类
 

public class Dwr{
	//获取上下文关系
	private WebContext getWebContext() {
		return WebContextFactory.get();
	}
	
	//获取sesion
	public HttpSession getSession() {
		return getWebContext().getSession();
	}
	
	//获取Request
	public HttpServletRequest getHttpServletRequest() {
		return getWebContext().getHttpServletRequest();
	}
	
	//获取Response
	public HttpServletResponse getHttpServletResponse() {
		return getWebContext().getHttpServletResponse();
	}
	
	//获取sesion id
	public String getSessionId(){
		return getSession().getId();
	}
	
	//写入sesion
	public void setSession(String name,Object objct){
		getSession().setAttribute(name, objct);
	}
	
	//写入清除sesion
	public void deleteSession(String name){
		getSession().removeAttribute(name);
	}
	
	//获取 getApplicationContext
	public ApplicationContext getApplicationContext(){
		return WebApplicationContextUtils.getWebApplicationContext(getWebContext().getServletContext());
	}
	
	//获取 spring 注入
	public Object getBean(String key){
		return getApplicationContext().getBean(key);
	}
}

5.DwrMethod类

public class DwrMethod extends Dwr{
	UtilService utilService = (UtilService) super.getBean("utilService");
	public String isNotRep(String code) throws Exception{
		if(code!=null && !"".equals(code)){
			return this.utilService.isNotRep("from TblCgDistrict t where t.isDele=0 and t.code="+code);
		}else{
			return "2";
		}
	}
	
	public List getBatch(String yearid) throws Exception{
		if(yearid!=null && !"".equals(yearid)){
			String []str = yearid.split(",");
			return this.utilService.getHqlQuery("from TblCgBatch t where t.isDele=0 and t.fkYear.id="+str[0]);
		}else{
			return null;
		}
	}
	
	/**
	 * 成果类别级联查询
	 */
	public List getProductionType(String parentId) throws Exception{
		if(parentId!=null && !"".equals(parentId)){
			return this.utilService.getHqlQuery("from TblCgProductionType p where p.isDele=0 and p.parentId="+Integer.parseInt(parentId));
		}else{
			return null;
		}
	}
}

6.页面：

<script type='text/javascript' src='/bjkpcg/dwr/interface/dwrMethod.js'></script>
  	<script type='text/javascript' src='/bjkpcg/dwr/engine.js'></script>
    <script type='text/javascript' src='/bjkpcg/dwr/util.js'></script>
	
	<script language="javascript">
		function getNext(t){
			var parentId="";
			if(t==1){
				parentId = document.getElementById("bselect1").value;
				if(parentId!=""){
					dwrMethod.getProductionType(parentId,callback1);
				}
			}else{
				parentId = document.getElementById("btype2").value;
				if(parentId!=""){
					dwrMethod.getProductionType(parentId,callback2);
				}else{
					document.getElementById("btype3").options.length=0;
		   			var option = new Option("--  请选择  --", "");
		   			document.getElementById("btype3").add(option);
				}
			}
		}
		
		function callback1(provinces){
			document.getElementById("btype2").options.length=0;
			document.getElementById("btype3").options.length=0;
   			var option = new Option("--  请选择  --", "");
   			var option1 = new Option("--  请选择  --", "");
   			document.getElementById("btype2").add(option);
   			document.getElementById("btype3").add(option1);
   			var pid = document.getElementById("bselect1").value;
   			for(var i=0;i< provinces.length;i ++){
     			var value = provinces[i].id;
     			var text = provinces[i].productionTypeName;
     			var option = new Option(text, value);
<%--     			if(provinces[i].id==pid){--%>
<%--   					option.selected=true;--%>
<%--   				}--%>
		        try{
		          document.getElementById("btype2").add(option);
		        }catch(e){
		        }
   			}
   		}
   		
   		function callback2(provinces){
			document.getElementById("btype3").options.length=0;
   			var option = new Option("--  请选择  --", "");
   			document.getElementById("btype3").add(option);
   			var pid = document.getElementById("btype2").value;
   			for(var i=0;i< provinces.length;i ++){
     			var value = provinces[i].id;
     			var text = provinces[i].productionTypeName;
     			var option = new Option(text, value);
     			if(provinces[i].id==pid){
   					option.selected=true;
   				}
		        try{
		          document.getElementById("btype3").add(option);
		        }catch(e){
		        }
   			}
   		}
	</script>

<tr>
									<td class="add_tit">成果类型</td>
									<td>
										<s:select id="bselect1" name="pruType1" onchange="getNext(1)" list="pTypeList" listKey="id" listValue="productionTypeName" headerKey="" headerValue="--  请选择  --" />
										<label class="note4">*</label>
									</td>
								</tr>
								<tr>
									<td class="add_tit">二级分类</td>
									<td>
										<select id="btype2" name="pruType2" onchange="getNext(2)" style="width:155px;">
								   			<option value="">--  请选择  --</option>
								   		</select>
									</td>
								</tr>
								<tr>
									<td class="add_tit">三级分类</td>
									<td>
										<select id="btype3" name="pruType3" style="width:155px;">
								   			<option value="">--  请选择  --</option>
								   		</select>
									</td>
								</tr>