struts ajax多级下拉菜单

2022-10-23 14:56:45

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

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

<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
    "http://struts.apache.org/dtds/struts-2.1.dtd">

<struts>
    <constant name="struts.devMode" value="true"></constant>
    <package name="test" namespace="/" extends="struts-default">
         <action name="getProvince" class="cdm.module.file.action.SearchFileAction" method="getProvince">
        <result>/testSelect.jsp</result>
        </action>
    </package>

    <package name="searchFileJSON" namespace="/" extends="json-default">
        <action name="getMunicipality" class="cdm.module.file.action.SearchFileAction" method="getMunicipality">
            <result type="json">
                <param name="root">municipalities</param>
            </result>
        </action>
    </package>
</struts>

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<Municipality> municipalities;

    public List<Province> provinces=new ArrayList<Province>();

    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<Municipality>();
        //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"%>
<html>
<head>
<title></title>

        <script type="text/javascript" src="js/json2.js"></script>
        <script type="text/javascript" src="js/prototype.js"></script>
        <script type="text/javascript" src="js/findInf.js"></script>
</head>
<body>
    <br>

    <table class="tab_frm" >
                    <tr>
                        <td class="left" width="5%">
                            省级别
                        </td>
                        <td class="left" width="18%">
                            市级别
                        </td>

                    </tr>
                    <tr>

                        <td class="center" width="5%">
                            <s:select  id="categoryId0" list="provinces"
                                listKey="id" listValue="name" headerKey="-1"
                                headerValue="-请选择省-" theme="simple"
                                onchange="getProvince(this)" />
                        </td>
                        <td class="center" width="18%">
                            <s:select  id="conditionId0" list="#{'-1':'-请先选择省-'}"
                                theme="simple" disabled="true" />
                        </td>
                    </tr>
    </table>

</body>
</html>

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

        <script type="text/javascript" src="js/json2.js"></script>
        <script type="text/javascript" src="js/prototype.js"></script>
        <script type="text/javascript" src="js/findInf.js"></script>

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

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