使用mybatis将数据库中的记录
1.前台jsp页面，将要删除的记录选中，通过将记录的id对记录进行区别，请求方法为post；
2.使用jQuery，js对页面进行全选，或全部清除选择。
3.servlet控制层，通过req对象获取id，然后将存放id数组进行参数类型转换，转为int[];
4.sevice服务层，使用数据库连接池，获取SqlSession实例对象，由session对象获取Mybatis框架创建的接口的实例，通过声明接口中处理批量删除的方法，配置接口对应的xml配置文件。
1，前台jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>商品列表</title>
<script type="text/javascript" src="/mybatis_demo1/js/jquery-1.11.2.js"></script>
<script type="text/javascript">
$(function(){
$("#checkAll").click(function(){
var ckd=this.checked;
if(ckd)
$("input[name='checkedPrdId']").prop("checked",true);
else
$("input[name='checkedPrdId']").removeProp("checked");
});
});
</script>
<style type="text/css">
table,table td{
border:1px solid black;
}
table {
border-collapse: collapse;
}
table td{
width: 200px;
height: 20px;
}
</style>
</head>
<body>
prdList
<c:if test="${not empty prdList}">
<form action="/mybatis_demo1/prdServlet?flag=batchDelete" method="post">
<input type="submit" value="批量删除"/>${msg} <br/>
<table>
<thead>
<tr>
<td><input type="checkbox" id="checkAll" /></td>
<td>商品编号</td>
<td>商品类别</td>
<td>商品名称</td>
<td>商品价格</td>
<td>商品描述</td>
</tr>
</thead>
<tbody>
<c:forEach items="${prdList}" var="prd">
<tr>
<td><input type="checkbox" name="checkedPrdId" value="${prd.prdId}" /></td>
<td>${prd.prdId}</td>
<td>${prd.typeId}</td>
<td>${prd.prdName}</td>
<td>${prd.price}</td>
<td>${prd.desc}</td>
</tr>
</c:forEach>
</tbody>
</table>
</form>
</c:if>
</body>
</html>
2.servlet类的post方法的实现
package com.xixi.demo.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
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 com.sun.javafx.collections.MappingChange.Map;
import com.xixi.demo.common.Constants;
import com.xixi.demo.service.ProductService;
import com.xixi.demo.service.ProductTypeService;
import com.xixi.demo.vo.ProductInfo;
import com.xixi.demo.vo.ProductTypeInfo;
@WebServlet(urlPatterns="/prdServlet")
public class ProductServlet extends BaseServlet {
private ProductService productService = new ProductService();
private ProductTypeService productTypeService = new ProductTypeService();
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
String flag = req.getParameter("flag");
if("add".equals(flag)){
...
}else if("search".equals(flag)){
...
}else if("batchDelete".equals(flag)){
int count = 0;
String[] values = req.getParameterValues("checkedPrdId");
if(values!=null&&values.length>0 ){
int[] prdId = new int[values.length];
for(int i=0; i<values.length; i++){
prdId[i] = Integer.parseInt(values[i]);
}
count = this.productService.batchDelete(prdId);
}
req.setAttribute("msg", "删除"+count+"条记录！");
//获取产品列表
List<ProductInfo> prdList = this.productService.getAllProducts();
req.setAttribute("prdList", prdList);
req.getRequestDispatcher("/prd/prd_list.jsp").forward(req, resp);
}
}
}
3.service层实现
package com.xixi.demo.service;
import com.sun.javafx.collections.MappingChange.Map;
import com.xixi.demo.common.Constants;
import java.util.HashMap;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import com.xixi.demo.common.DBUtils;
import com.xixi.demo.dao.ProductMapper;
import com.xixi.demo.vo.ProductInfo;
public class ProductService {
/**
*
*获取所有产品
*
* @return
*/
public List<ProductInfo> getAllProducts() {
...
}
/**
*
* 商品检索
*
* @param condition
* @param pageNum
* @return
*/
public List<ProductInfo> search(HashMap<String, Object> condition, int pageNum) {
...
}
/**
*
* 获取总页数
*
* @param condition
* @return
*/
public int getPageCount(HashMap<String, Object> condition) {
...
}
/**
* 批量删除
*
* @param prdId
* @return
*/
public int batchDelete(int[] prdId) {
SqlSession session = DBUtils.getSqlSession();
ProductMapper prdMapper = session.getMapper(ProductMapper.class);
int count=0;
try {
count = prdMapper.batchDelete(prdId);
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
session.close();
}
return count;
}
}
4.DAO层的mybatis框架接口实现
package com.xixi.demo.dao;
import java.util.HashMap;
import java.util.List;
import com.sun.javafx.collections.MappingChange.Map;
import com.xixi.demo.vo.ProductInfo;
public interface ProductMapper {
//获取所有的产品
List<ProductInfo> getAllProducts();
//通过某一个产品编号查询产品信息
ProductInfo getInfoById(Integer prdId);
//录入新的商品
int saveInfo(ProductInfo info);
//检索商品
List<ProductInfo> search(HashMap<String, Object> condition);
//获取产品记录条数
int getRecordCount(HashMap<String, Object> condition);
//批量删除
int batchDelete(int[] prdId);
}
5.DAO层的mybatis框架接口对应的xml配置文件的实现
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<delete id="batchDelete" parameterType="_int[]">
delete from products where productId IN
<foreach collection="array" open="(" close=")" separator="," item="id">#{id}</foreach>
</delete>
</mapper>
注意：
mybatis对于批量删除的过程中，参数为一个数组的情况，我们采用mybatis提供的<foreach>标签将参数进行逐个与数据库id进行比对，完成批量删除操作。
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