本人已参与[新人创作礼]活动，一起开启掘金创作之路。

一、综合案例

二、环境搭建

三、查询所有

四、新增品牌

五、Servlet代码优化

六、批量删除

七、项目结构

八、代码实现

package com.itheima.mapper;

import com.itheima.pojo.Brand;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
* Description:查询所有
* @date:2022/3/31 16:40
* @params:
* @return:
*/
public interface BrandMapper {
   @Select("select * from tb_brand")
   @ResultMap("brandResultMap")
   List<Brand> selectAll();
   
/**
* Description:添加数据
* @date:2022/3/31 20:32
* @params: [com.itheima.pojo.Brand]
* @return: void 
*/        
   @Insert("insert into tb_brand values(null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
   void add(Brand brand);


   /**
   * Description:批量删除
   * @date:2022/4/1 9:31
   * @params: [int[]]
   * @return: void
   */

   void deleteByIds(@Param("ids") int[] ids);//数组型参数ids，使用注解@Param映射这个名字
}

package com.itheima.pojo;

public class Brand {
    // id 主键
    private Integer id;
    // 品牌名称
    private String brandName;
    // 企业名称
    private String companyName;
    // 排序字段
    private Integer ordered;
    // 描述信息
    private String description;
    // 状态：0：禁用  1：启用
    private Integer status;


    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getBrandName() {
        return brandName;
    }

    public void setBrandName(String brandName) {
        this.brandName = brandName;
    }

    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Integer getStatus() {
        return status;
    }
    //逻辑视图
    public String getStatusStr(){
        if (status == null){
            return "未知";
        }
        return status == 0 ? "禁用":"启用";
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    @Override
    public String toString() {
        return "Brand{" +
                "id=" + id +
                ", brandName='" + brandName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", ordered=" + ordered +
                ", description='" + description + '\'' +
                ", status=" + status +
                '}';
    }
}

package com.itheima.service.impl;

import com.itheima.mapper.BrandMapper;
import com.itheima.pojo.Brand;
import com.itheima.service.BrandService;
import com.itheima.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import java.util.List;

/**
 * Created on 2022/3/31.
 *
 * @author Hou chaof
 */
public class BrandServiceImpl implements BrandService {
    //1.创建SqlSessionFactory 工厂对象
    SqlSessionFactory factory= SqlSessionFactoryUtils.getSqlSessionFactory();

    @Override
    public List<Brand> selectAll() {
        //2.获取SqlSession对象
        SqlSession sqlSession = factory.openSession();
        //3.获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
        //4.调用方法
        List<Brand> brands = mapper.selectAll();
        //5.释放资源
        sqlSession.close();
        return brands;
    }

    @Override
    public void add(Brand brand) {
        //2.获取SqlSession对象
        SqlSession sqlSession = factory.openSession();
        //3.获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
        //4.调用方法
        mapper.add(brand);
        //提交事务
        sqlSession.commit();
        sqlSession.close();
    }

    @Override
    public void deleteByIds(int[] ids) {
        //2.获取SqlSession对象
        SqlSession sqlSession = factory.openSession();
        //3.获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
        mapper.deleteByIds(ids);
        sqlSession.commit();
        sqlSession.close();
    }
}

package com.itheima.service;

import com.itheima.pojo.Brand;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * Created on 2022/3/31.
 *
 * @author Hou chaof
 */
public interface BrandService {
    /**
    * Description:查询所有
    * @date:2022/3/31 16:42
    * @params: []
    * @return: List<Brand>
    */
    List<Brand> selectAll();


    void add(Brand brand);



    void deleteByIds( int[] ids);//数组型参数ids，使用注解@Param映射这个名字

}

package com.itheima.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        //静态代码块会随着类的加载而自动执行，且只执行一次
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}

package com.itheima.web.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * Created on 2022/3/31.
 * 替换HttpServlet，根据请求的最后一段路径来进行方法分发
 * @author Hou chaof
 */
public class BaseServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1.获取请求路径
        String uri = req.getRequestURI();// /brand/selectAll
        //2.获取最后一段路径，方法名
        int index=uri.lastIndexOf("/");
        String methodName = uri.substring(index+1);
        //2，执行方法
                //2.1获取BrandServlet  UserServlet字节码对象Class
               //谁调用this所在的方法，this就代表谁
        Class<? extends BaseServlet> aClass = this.getClass();

        //2.2获取方法Method对象
        try {
            Method method = aClass.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            //2.3执行方法
            try {
                method.invoke(this,req,resp);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            }
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }



    }
}

package com.itheima.web.servlet;

import com.alibaba.fastjson.JSON;
import com.itheima.pojo.Brand;
import com.itheima.service.BrandService;
import com.itheima.service.impl.BrandServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.List;

/**
 * Created on 2022/3/31.
 *
 * @author Hou chaof
 */
@WebServlet("/brand/*")

public class BrandServlet extends BaseServlet{
    private BrandService brandService=new BrandServiceImpl();
    public void selectAll(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
        //1.调用service查询
        List<Brand> brands = brandService.selectAll();
        //2.转为JSON
        String jsonString = JSON.toJSONString(brands);
        //3.写数据
        resp.setContentType("text/json;charset=utf-8");
        resp.getWriter().write(jsonString);
    }

    public void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
        //1.接收品牌数据
        BufferedReader reader = req.getReader();
        String s = reader.readLine();//JSON字符串
        //转换为Brand对象
        Brand brand = JSON.parseObject(s, Brand.class);
        //2.调用service添加
        brandService.add(brand);
        //3.响应成功的标识
        resp.getWriter().write("success");
    }

/**
* Description:批量删除
* @date:2022/4/1 9:41
* @params: [javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse]
* @return: void
*/
    public void deleteByIds(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException{
        //1.接收数据  [1,2,3]
        BufferedReader reader = req.getReader();
        String s = reader.readLine();//JSON字符串
        //转换为int[]
        int[] ids = JSON.parseObject(s, int[].class);
        //2.调用service添加
        brandService.deleteByIds(ids);
        //3.响应成功的标识
        resp.getWriter().write("success");
    }
}

<?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">
<mapper namespace="com.itheima.mapper.BrandMapper">

    <resultMap id="brandResultMap" type="brand">
        <result property="brandName" column="brand_name" />
        <result property="companyName" column="company_name" />
    </resultMap>


    <delete id="deleteByIds">
        delete from tb_brand where  id in
        <foreach collection="ids" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>
</mapper>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <typeAliases>
        <package name="com.itheima.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///db1?useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
       <!--扫描mapper-->
        <package name="com.itheima.mapper"/>
    </mappers>
</configuration>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .el-table .warning-row {
            background: oldlace;
        }

        .el-table .success-row {
            background: #f0f9eb;
        }
    </style>

</head>
<body>
<div id="app">

    <!--搜索表单-->
    <el-form :inline="true" :model="brand" class="demo-form-inline">

        <el-form-item label="当前状态">
            <el-select v-model="brand.status" placeholder="当前状态">
                <el-option label="启用" value="1"></el-option>
                <el-option label="禁用" value="0"></el-option>
            </el-select>
        </el-form-item>

        <el-form-item label="企业名称">
            <el-input v-model="brand.companyName" placeholder="企业名称"></el-input>
        </el-form-item>

        <el-form-item label="品牌名称">
            <el-input v-model="brand.brandName" placeholder="品牌名称"></el-input>
        </el-form-item>

        <el-form-item>
            <el-button type="primary" @click="onSubmit">查询</el-button>
        </el-form-item>
    </el-form>

    <!--按钮-->

    <el-row>

        <el-button type="danger" plain @click="deleteByIds">批量删除</el-button>
        <el-button type="primary" plain @click="dialogVisible = true">新增</el-button>

    </el-row>
    <!--添加数据对话框表单-->
    <el-dialog
            title="编辑品牌"
            :visible.sync="dialogVisible"
            width="30%"
    >

        <el-form ref="form" :model="brand" label-width="80px">
            <el-form-item label="品牌名称">
                <el-input v-model="brand.brandName"></el-input>
            </el-form-item>

            <el-form-item label="企业名称">
                <el-input v-model="brand.companyName"></el-input>
            </el-form-item>

            <el-form-item label="排序">
                <el-input v-model="brand.ordered"></el-input>
            </el-form-item>

            <el-form-item label="备注">
                <el-input type="textarea" v-model="brand.description"></el-input>
            </el-form-item>

            <el-form-item label="状态">
                <el-switch v-model="brand.status"
                           active-value="1"
                           inactive-value="0"
                ></el-switch>
            </el-form-item>


            <el-form-item>
                <el-button type="primary" @click="addBrand">提交</el-button>
                <el-button @click="dialogVisible = false">取消</el-button>
            </el-form-item>
        </el-form>

    </el-dialog>


    <!--表格-->
    <template>
        <el-table
                :data="tableData"
                style="width: 100%"
                :row-class-name="tableRowClassName"
                @selection-change="handleSelectionChange"
        >
            <el-table-column
                    type="selection"
                    width="55">
            </el-table-column>
            <el-table-column
                    type="index"
                    width="50">
            </el-table-column>

            <el-table-column
                    prop="brandName"
                    label="品牌名称"
                    align="center"
            >
            </el-table-column>
            <el-table-column
                    prop="companyName"
                    label="企业名称"
                    align="center"
            >
            </el-table-column>
            <el-table-column
                    prop="ordered"
                    align="center"
                    label="排序">
            </el-table-column>
            <el-table-column
                    prop="status"
                    align="center"
                    label="当前状态">
            </el-table-column>

            <el-table-column
                    align="center"
                    label="操作">

                <el-row>
                    <el-button type="primary">修改</el-button>
                    <el-button type="danger">删除</el-button>
                </el-row>

            </el-table-column>

        </el-table>
    </template>

    <!--分页工具条-->
    <el-pagination
            @size-change="handleSizeChange"
            @current-change="handleCurrentChange"
            :current-page="currentPage"
            :page-sizes="[5, 10, 15, 20]"
            :page-size="5"
            layout="total, sizes, prev, pager, next, jumper"
            :total="400">
    </el-pagination>

</div>


<script src="js/vue.js"></script>
<script src="element-ui/lib/index.js"></script>
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css">
<script src="js/axios-0.18.0.js"></script>


<script>
    new Vue({
        el: "#app",

        mounted() {
            this.selectAll();
            /*//当页面加载完成后，发送异步请求，获取数据

            var _this = this;
            axios({
                method: "get",
                url: "http://localhost:8080/selectAllServlet"
            }).then(function (resp) {
                _this.tableData = resp.data;
            })*/
        },

        methods: {

            //查询所有的方法
            selectAll() {
            //当页面加载完成后，发送异步请求，获取数据
                var _this = this;
                axios({
                    method: "get",
                    url: "http://localhost:8080/brand/selectAll"
                }).then(function (resp) {
                    _this.tableData = resp.data;
                })
            },
            tableRowClassName({row, rowIndex}) {
                if (rowIndex === 1) {
                    return 'warning-row';
                } else if (rowIndex === 3) {
                    return 'success-row';
                }
                return '';
            },
            // 复选框选中后执行的方法
            handleSelectionChange(val) {
                this.multipleSelection = val;

                console.log(this.multipleSelection)
            },
            // 查询方法
            onSubmit() {
                console.log(this.brand);
            },
            // 添加数据
            addBrand() {
                var _this = this;
                //发送ajax请求，添加数据
                axios({
                    method: "post",
                    url: "http://localhost:8080/brand/add",
                    data: _this.brand
                }).then(function (resp) {
                    if (resp.data == "success") {
                        //添加成功

                        //关闭窗口
                        _this.dialogVisible = false;
                        //重新查询数据
                        _this.selectAll();
                            _this.$message({
                                message: '恭喜你，添加成功',
                                type: 'success'
                            });
                    }
                })

            },

            //分页
            handleSizeChange(val) {
                console.log(`每页 ${val} 条`);
            },
            handleCurrentChange(val) {
                console.log(`当前页: ${val}`);
            },

            //批量删除
            deleteByIds(){
                //弹出确认的提示框
                this.$confirm('此操作将永久删除该数据, 是否继续?', '提示', {
                    confirmButtonText: '确定',
                    cancelButtonText: '取消',
                    type: 'warning'
                }).then( () => {
                        //用户点击确认按钮

                        //1.创建id数组[1,2,3] this.multipleSelection 获取即可
                        for (let i = 0; i < this.multipleSelection.length; i++) {
                        let selectionElement = this.multipleSelection[i];
                        this.selectedIds[i] = selectionElement.id;

                    }
                        //2.发送ajax请求
                        var _this=this;
                        axios({
                                  method: "post",
                                  url: "http://localhost:8080/brand/deleteByIds",
                                  data: _this.selectedIds
                              }).then(function (resp) {
                            if(resp.data == "success") {
                                //删除成功

                                //重新查询数据
                                _this.selectAll();
                                _this.$message({
                                    message: '恭喜你，删除成功',
                                    type: 'success'
                                });
                            }
                        })
                    }).catch(() => {
                        //用户点击取消按钮
                        this.$message({
                            type: 'info',
                            message: '已取消'
                        });
                    });


                    //1.创建id数组[1,2,3] this.multipleSelection 获取即可
                    for (let i = 0; i < this.multipleSelection.length; i++) {
                        let selectionElement = this.multipleSelection[i];
                        this.selectedIds[i] = selectionElement.id;

                    }
                    var _this=this;
                    //2.发送ajax请求
                    axios({
                        method: "post",
                        url: "http://localhost:8080/brand/deleteByIds",
                        data: _this.selectedIds
                    }).then(function (resp) {
                        if (resp.data == "success") {
                            //删除成功

                            //重新查询数据
                            _this.selectAll();
                            _this.$message({
                                message: '恭喜你，删除成功',
                                type: 'success'
                            });
                        }
                    })
                }
        },
        data() {
            return {
                // 当前页码
                currentPage: 4,
                // 添加数据对话框是否展示的标记
                dialogVisible: false,

                // 品牌模型数据
                brand: {
                    status: '',
                    brandName: '',
                    companyName: '',
                    id: "",
                    ordered: "",
                    description: ""
                },
                //被选中的id数组
                selectedIds:[],
                // 复选框选中数据集合
                multipleSelection: [],
                // 表格数据
                tableData: [{
                    brandName: '华为',
                    companyName: '华为科技有限公司',
                    ordered: '100',
                    status: "1"
                }, {
                    brandName: '华为',
                    companyName: '华为科技有限公司',
                    ordered: '100',
                    status: "1"
                }, {
                    brandName: '华为',
                    companyName: '华为科技有限公司',
                    ordered: '100',
                    status: "1"
                }, {
                    brandName: '华为',
                    companyName: '华为科技有限公司',
                    ordered: '100',
                    status: "1"
                }]
            }
        }
    })

</script>

</body>
</html>

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>brand-case</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>


    <dependencies>
        <!--Servlet-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>


        <!--MyBatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <!--MySQL-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>


        <!--fastjson-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
    </dependencies>

</project>