struts ajax多级下拉菜单

先看项目截图:


看看要加入的jar包
除了struts核心的那个几个之外,我们还需要这两个


OK先看struts.xml

    
      
         
        /testSelect.jsp    
        
    
    
    
        
            
                municipalities
            
        
    

我们看看用于处理请求的类。

package cdm.module.file.action;

import java.util.ArrayList;
import java.util.List;
import com.opensymphony.xwork2.ActionSupport;


public class SearchFileAction extends ActionSupport {


    /**
     *
     */
    private static final long serialVersionUID = -6756954284459457436L;

    public int provinceId;
    
    public List municipalities;
    
    public List provinces=new ArrayList();
    
    public String getProvince(){
        //下面的为模拟数据库操作
        Province p1=new Province();
        p1.setId(1);
        p1.setName("陕西省");
        
        Province p2=new Province();
        p2.setId(2);
        p2.setName("山西省");
        
        provinces.add(p1);
        provinces.add(p2);
        return SUCCESS;
    }
    
    public String getMunicipality(){
        municipalities=new ArrayList();
        //下面的为模拟数据库操作
        if (provinceId==1) {          
            Municipality municipality=new Municipality();
            municipality.setId(1);
            municipality.setName("咸阳市");
            municipality.setProvinceId(1);
            municipalities.add(municipality);
            municipality=new Municipality();
            municipality.setId(2);
            municipality.setName("西安市");
            municipality.setProvinceId(1);
            municipalities.add(municipality);
        }
        
        if (provinceId==2) {
            Municipality municipality=new Municipality();
            municipality.setId(1);
            municipality.setName("运城市");
            municipality.setProvinceId(2);
            municipalities.add(municipality);
            municipality=new Municipality();
            municipality.setId(2);
            municipality.setName("太原市");
            municipality.setProvinceId(2);
            municipalities.add(municipality);
        }
        System.out.println(municipalities.get(0).getName()+"sdfs");
        
        return SUCCESS;
    }

    //省略三个实例变量的getset方法
}

至于Municipality,与Province,省里面有个一id和name,市除了id和name外还有一个provinceId,来指示它位于哪个省。



testSelect.jsp也很简单就是下面代码示例。

<%@ page contentType="text/html; charset=GB2312"%>
<%@taglib prefix="s" uri="/struts-tags"%>



        
        
        
        


    

  
    

                    

                        

                            省级别
                        
                        

                            市级别
                        
                
                    
                    


                        

                            
                        
                        

                            
                        
                        
                    
    

核心在引入的findInf.js,代码如下:

function getProvince(obj) {

    var provinceId = obj.options[obj.selectedIndex].value;
    var select = document.getElementById("conditionId0");

    if (provinceId < 0) {
        select.innerHTML = "";
        select1.innerHTML = "";
        var con = new Option();
        con.text = "-请先选择省-";
        con.value = "-1";
        var mat = new Option();
        mat.text = "-请先选择省-";
        mat.value = "-1";
        select.options.add(con);

        select.disabled=true;

        return;
    }
    var url = "getMunicipality.action?provinceId=" + provinceId;
    new Ajax.Request(url, {method:"post", onComplete:function (request) {
        select.innerHTML = "";
        var o = new Option();
        o.text = "-请选择市-";
        o.value = "-1";
        select.options.add(o);
        var tableList = JSON.parse(request.responseText);
        for (var i = 0; i < tableList.length; i++) {
            var _o = new Option();
            _o.text = tableList[i].name;
            _o.value = tableList[i].id;
            select.options.add(_o);
        }
        select.disabled=false;
    }, asynchronous:true});
}

完工!

遇到的几个问题

findInf要等上面两个引入后才能引用。
当时复制的时候没有注意这一点。

启用firefox的调试功能,看到Ajax is not define 才想到这个问题。

其他资料:

http://www.jb51.net/article/37316.htm

http://www.wzsky.net/html/Website/Javascript/126012.html

http://www.w3school.com.cn/jquery/ajax_ajax.asp