案例实现三级联动
4.5.1 数据准备
使用china.sql生成area表格
项目搭建
jsp代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title%sSourceCode%lt;/title>
<script src="js/jquery.min.js"></script>
<script>
$(function(){
// 获取所有的省份信息
showArea(0,"#provience")
})
function showArea(val,selectID){
$.ajax({
type:"GET",
url:"areaController.do",
data:{parentID:val},
dataType:"json",
success:function(areas){
// 清除上一次选择省份时,遗留的城市
$(selectID).html('<option>-请选择-</option>');
$.each(areas,function(i,e){
$(selectID).append('<option value="'+e.areaid+'">'+e.areaname+'</option>')
})
if(selectID== "#city"){
$("#qu").html('<option>-请选择-</option>');
}
}
})
}
</script>
</head>
<body>
籍贯:
<select id="provience" onchange="showArea(this.value,'#city')">
<option>-请选择-</option>
</select>
<select id="city" onchange="showArea(this.value,'#qu')">
<option>-请选择-</option>
</select>
<select id="qu">
<option>-请选择-</option>
</select>
</body>
</html>
AreaController代码
package com.msb.controller;
import com.google.gson.Gson;
import com.msb.dao.AreaDao;
import com.msb.dao.impl.AreaDaoImpl;
import com.msb.pojo.Area;
import com.msb.service.AreaService;
import com.msb.service.impl.AreaServiceImpl;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
/**
* @Author: Ma HaiYang
* @Description: MircoMessage:Mark_7001
*/
@WebServlet("/areaController.do")
public class AreaController extends HttpServlet {
private AreaService areaService=new AreaServiceImpl();
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
Integer parentID=0;
try {
parentID= Integer.parseInt(req.getParameter("parentID"));
} catch (NumberFormatException e) {
e.printStackTrace();
}
List<Area> areas=areaService.findByParentID(parentID);
String json = new Gson().toJson(areas);
resp.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=UTF-8");
resp.getWriter().print(json);
}
}
AreaService代码
package com.msb.service.impl;
import com.msb.dao.AreaDao;
import com.msb.dao.impl.AreaDaoImpl;
import com.msb.pojo.Area;
import com.msb.service.AreaService;
import java.util.List;
/**
* @Author: Ma HaiYang
* @Description: MircoMessage:Mark_7001
*/
public class AreaServiceImpl implements AreaService {
private AreaDao areaDao =new AreaDaoImpl();
@Override
public List<Area> findByParentID(Integer parentID) {
List<Area> areas = areaDao.findByParentID(parentID);
return areas;
}
}
AreaDao代码
package com.msb.dao.impl;
import com.msb.dao.AreaDao;
import com.msb.dao.BaseDao;
import com.msb.pojo.Area;
import java.util.List;
/**
* @Author: Ma HaiYang
* @Description: MircoMessage:Mark_7001
*/
public class AreaDaoImpl extends BaseDao implements AreaDao {
@Override
public List<Area> findByParentID(int parentID) {
String sql="select * from area where parentid= ?";
return baseQuery(Area.class, sql, parentID);
}
}
测试效果
标签：dao,List,案例,联动,parentID,import,com,msb,三级 From： https://www.cnblogs.com/89564f/p/17029225.html