easyui下拉框动态级联加载的示例代码

<span>学院名称：</span> 
<input class="easyui-combobox" style="width:30%;" id="collegeName"> 
<span>课程名称：</span> 
<input class="easyui-combobox" style="width:30%;" id="courseName"><br/> 

$(function() {    
   // 下拉框选择控件，下拉框的内容是动态查询数据库信息 
   $('#collegeName').combobox({  
       url:'${pageContext.request.contextPath}/loadInstitution',  
       editable:false, //不可编辑状态 
       cache: false, 
       panelHeight: '150', 
       valueField:'id',   
       textField:'institutionName', 
        
    onHidePanel: function(){ 
      $("#courseName").combobox("setValue",'');//清空课程 
      var id = $('#collegeName').combobox('getValue');     
      //alert(id); 
       
     $.ajax({ 
      type: "POST", 
      url: '${pageContext.request.contextPath}/loadCourse"json", 
      success: function(data){ 
      $("#courseName").combobox("loadData",data); 
           } 
        });    
       } 
});   
    
   $('#courseName').combobox({  
     //url:'itemManage!categorytbl',  
     editable:false, //不可编辑状态 
     cache: false, 
     panelHeight: '150',//自动高度适合 
     valueField:'id',   
     textField:'courseName' 
     }); 
    
}); 

@RequestMapping("/loadInstitution") 
  /** 
   * 加载学院 
   * @param  
   * @param  
   * @return void 
   * @exception/throws [违例类型] [违例说明] 
   * @see     [类、类#方法、类#成员] 
   * @deprecated 
   */ 
  public void loadInstitute(HttpServletRequest request, 
      HttpServletResponse response) throws Exception { 
    try { 
      JackJsonUtils JackJsonUtils = new JackJsonUtils(); 
      List<Institution> institutionList = institutionBean 
          .queryAllColleage(); 
      System.out.println("学院list大小=====" + institutionList.size()); 
      String result = JackJsonUtils.BeanToJson(institutionList); 
      System.out.println(result); 
      JsonUtils.outJson(response, result); 
    } catch (Exception e) { 
      logger.error("加载学院失败", e); 
    } 
  } 
 
  @RequestMapping("/loadCourse") 
  /** 
   * 动态加载课程 
   * 
   * 
   * @param  
   * @param  
   * @return void 
   * @exception/throws [违例类型] [违例说明] 
   * @see     [类、类#方法、类#成员] 
   * @deprecated 
   */ 
  public void loadCourse(HttpServletRequest request, 
      HttpServletResponse response) throws Exception { 
    JackJsonUtils JackJsonUtils = new JackJsonUtils(); 
    String id = request.getParameter("id"); 
    System.out.println("学院id====" + id); 
    try { 
      if(id != null && id != ""){ 
        List<CourseInfo> listCourseInfoList = courseBean 
            .queryAllCourseInfos(id); 
        System.out.println("课程list大小=====" + listCourseInfoList.size()); 
        String result = JackJsonUtils.BeanToJson(listCourseInfoList); 
        System.out.println(result); 
        JsonUtils.outJson(response, result); 
      } 
    } catch (Exception e) { 
      logger.error("加载课程失败", e); 
    } 
  }