Mybatis实现品牌数据的增删改查

项目目录如下图所示。Mapper包用于存储对数据库进行操作的Mapper接口文件，本文中通过注释的方式对sql语句进行编写。pojo包中存放实体类文件，文件中包含Brand对象相关字段的定义以及get、set、toString方法。service包中存放service层文件，调用mapper文件对数据库进行增删改查等操作。web包中存放servlet.java文件，接收来自前端界面的数据，将数据封装，传入service层中。util包中存放工具类，此处的SqlSessionFactoryUtils文件抽取了SqlSessionFactory方法，避免了其重复定义。

数据库信息

Brand Mapper.java
用于定义操纵数据库的接口函数，可以通过两种方式对接口函数进行实现（注解以及xml文件的方式），简单的sql语句可通过注解的方式进行实现，较为复杂的函数需通过xml进行实现。

package com.wu.mapper;
import com.wu.pojo.Brand;
import org.apache.ibatis.annotations.*;
import java.util.List;
public interface BrandMapper {

    /**
     * 查询所有
     *
     * @return
     */
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List<Brand> selectAll();

    /**
     * 添加品牌
     *
     * @param brand
     */
    @Insert("insert into tb_brand values (null, #{brandName}, #{companyName}, #{ordered}, #{description}, #{status})")
    void addBrand(Brand brand);

    /**
     * 根据id查询
     *
     * @param id
     * @return
     */
    @Select("select * from tb_brand where id = #{id}")
    @ResultMap("brandResultMap")
    Brand selectById(int id);

    /**
     * 更新品牌信息
     *
     * @param brand
     */
    @Update("update tb_brand set brand_name = #{brandName}, company_name = #{companyName}, " +
            "ordered = #{ordered}, description =#{description}, status = #{status} " +
            "where id = #{id}")
    void updateBrand(Brand brand);

    /**
     * 删除品牌
     *
     * @param id
     */
    @Delete("delete from tb_brand where id = #{id}")
    void deleteById(int id);
}

Brand.java
Brand实体类文件，定义了Brand对象的相关字段及方法。

package com.wu.pojo;

public class Brand  {
    private Integer id;
    private String brandName;
    private String companyName;
    private Integer ordered;
    private String description;
    private Integer status;

    public Integer getId() {
        return id;
    }

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

    public String getBrandName() {
        return brandName;
    }

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

    public String getCompanyName() {
        return companyName;
    }

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

    public Integer getOrdered() {
        return ordered;
    }

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

    public String getDescription() {
        return description;
    }

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

    public Integer getStatus() {
        return status;
    }

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

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

BrandService.java
Service层文件，通过定义sqlSessionFactory来调用brandMapper中的方法，从而实现对数据库的相关操作。

package com.wu.service;
import com.wu.mapper.BrandMapper;
import com.wu.pojo.Brand;
import com.wu.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import java.util.List;

public class BrandService {

    SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();

    /**
     * 查询所有成员
     * @return
     */
    public List<Brand> selectAll() {
        SqlSession sqlSession = sqlSessionFactory.openSession(true);//true事务的自动提交
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        List<Brand> brands = brandMapper.selectAll();
        sqlSession.close();
        return brands;
    }

    /**
     * 添加成员
     */
    public void addBrand(Brand brand){
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        brandMapper.addBrand(brand);
        sqlSession.close();
    }

    /**
     * 根据id查询
     * @return
     */
    public Brand selectById(int id) {
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        Brand brand = brandMapper.selectById(id);
        sqlSession.close();
        return brand;
    }

    /**
     * 修改品牌信息
     * @param brand
     */
    public void update(Brand brand){
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        brandMapper.updateBrand(brand);
        sqlSession.close();
    }

    /**
     * 删除品牌
     * @param id
     */
    public void deleteById(int id){
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
        brandMapper.deleteById(id);
        sqlSession.close();
    }
}

SqlSessionFactoryUtils.java

package com.wu.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
        String resource = "mybatis-config.xml";
        InputStream inputStream = null;
        try {
            inputStream = Resources.getResourceAsStream(resource);
        } catch (IOException e) {
            e.printStackTrace();
        }
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

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

AddServlet.java
接收前端界面传递的参数，将其封装为Brand对象，通过调用service层的方法实现添加操作。

package com.wu.web;
import com.wu.pojo.Brand;
import com.wu.service.BrandService;
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;

@WebServlet( "/addServlet")
public class AddServlet extends HttpServlet {

    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // 处理POST请求的乱码问题
        request.setCharacterEncoding("utf-8");

        // 接收表单提交的数据
        String brandName = request.getParameter("brandName");
        String companyName = request.getParameter("companyName");
        String ordered = request.getParameter("ordered");
        String description = request.getParameter("description");
        String status = request.getParameter("status");

        // 封装为Brand对象
        Brand brand = new Brand();
        brand.setBrandName(brandName);
        brand.setCompanyName(companyName);
        brand.setOrdered(Integer.parseInt(ordered));
        brand.setDescription(description);
        brand.setStatus(Integer.parseInt(status));

        // 调用service完成添加
        brandService.addBrand(brand);

        request.getRequestDispatcher("/selectAllServlet").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

DeleteByIdServlet.java
接收前端界面传递的id，调用service层的deleteById方法，将id传入，实现根据id删除的操作。

package com.wu.web;
import com.wu.service.BrandService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/deleteByIdServlet")
public class DeleteByIdServlet extends HttpServlet {

    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String id = request.getParameter("id");
        brandService.deleteById(Integer.parseInt(id));
        request.getRequestDispatcher("/selectAllServlet").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

SelectAllServlet.java
调用service层selectAll方法，查询所有数据，并将数据封装为Attribute进行转发。

package com.wu.web;
import com.wu.pojo.Brand;
import com.wu.service.BrandService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;

@WebServlet("/selectAllServlet")
public class SelectAllServlet extends HttpServlet {

    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1. 调用BrandService完成查询
        List<Brand> brands = brandService.selectAll();
        //2. 将brands存入request域中
        request.setAttribute("brands", brands);
        //3. 转发到brand.jsp页面
        request.getRequestDispatcher("/brand.jsp").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

SelectByIdServlet.java
接收前端界面传递的id，调用service层selectById方法，实现根据id查询，并将查询结果封装为attribute，转发到update.jsp页面。

package com.wu.web;
import com.wu.pojo.Brand;
import com.wu.service.BrandService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/selectByIdServlet")
public class SelectByIdServlet extends HttpServlet {

    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 接收id
        String id = request.getParameter("id");
        // 调用service查询
        Brand brand = brandService.selectById(Integer.parseInt(id));
        request.setAttribute("brand", brand);
        request.getRequestDispatcher("/update.jsp").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

UpdateServlet.java
接收前端界面传递来的参数，将其封装为brand对象，调用service层的update方法，实现更新操作。

package com.wu.web;
import com.wu.pojo.Brand;
import com.wu.service.BrandService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/updateServlet")
public class UpdateServlet extends HttpServlet {

    private BrandService brandService = new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("utf-8");//解决乱码问题

        String id = request.getParameter("id");
        String brandName = request.getParameter("brandName");
        String companyName = request.getParameter("companyName");
        String ordered = request.getParameter("ordered");
        String description = request.getParameter("description");
        String status = request.getParameter("status");

        Brand brand = new Brand();
        brand.setId(Integer.parseInt(id));
        brand.setBrandName(brandName);
        brand.setCompanyName(companyName);
        brand.setOrdered(Integer.parseInt(ordered));
        brand.setDescription(description);
        brand.setStatus(Integer.parseInt(status));

        brandService.update(brand);

        request.getRequestDispatcher("/selectAllServlet").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }
}

BrandMapper.xml
resultMap用于解决数据库字段名和对象名称不同而导致的匹配失败问题

DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.wu.mapper.BrandMapper">
    <resultMap id="brandResultMap" type="brand">
        <result column="brand_name" property="brandName">result>
        <result column="company_name" property="companyName">result>
    resultMap>
mapper>

mybatis-config.xml
数据库连接等相关操作

DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <typeAliases>
        <package name="com.wu.pojo"/>  
    typeAliases>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///mybatis?useSSL=false&userServerPrepStmts=true"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            dataSource>
        environment>
    environments>
    <mappers>
        

        
        
        <package name="com.wu.mapper"/>
    mappers>
configuration>

addBrand.jsp
添加品牌界面

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>addBrand</title>
</head>
<body>
<h3>添加品牌</h3>
<form action="/jsp-demo/addServlet" method="post"><br>
    品牌名称：<input name="brandName"><br>
    企业名称：<input name="companyName"><br>
    排序：<input name="ordered"><br>
    描述信息：<textarea rows="5" cols="20" name="description"></textarea><br>
    状态：<input type="radio" name="status" value="0">禁用
    <input type="radio" name="status" value="1">启用<br>
    <input type="submit" value="提交">
    <input type="reset" value="重置">
</form>
</body>
</html>

brand.jsp
展示全部品牌界面

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>brand</title><br>
</head>
<body>
<input type="button" value="新增" id="add">
<table border="1" cellpadding="0" width="800">
    <tr>
        <th>序号</th>
        <th>品牌名称</th>
        <th>企业名称</th>
        <th>排序</th>
        <th>品牌介绍</th>
        <th>状态</th>
        <th>操作</th>
    </tr>
    <c:forEach items="${brands}" var="brand" varStatus="status">
        <tr align="center">
            <td>${status.count}</td>
            <td>${brand.brandName}</td>
            <td>${brand.companyName}</td>
            <td>${brand.ordered}</td>
            <td>${brand.description}</td>
            <c:if test="${brand.status == 1}">
                <td>启用</td>
            </c:if>
            <c:if test="${brand.status != 1}">
                <td>禁用</td>
            </c:if>
            <td><a href="/jsp-demo/selectByIdServlet?id=${brand.id}">修改</a>
                <a href="/jsp-demo/deleteByIdServlet?id=${brand.id}">删除</a></td>
        </tr>
    </c:forEach>
</table>

<script>
    document.getElementById('add').onclick = function (){
        location.href = "/jsp-demo/addBrand.jsp"
    }
</script>
</body>
</html>

index.html
初始界面，仅包含select all超链接

DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Titletitle>
head>
<body>
    <a href="/jsp-demo/selectAllServlet">select alla>
body>
html>

update.jsp
更新界面，接收根据id查询到的参数，显示到界面上。对其进行修改，修改后的参数进行更新操作。

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>update</title>
</head>
<body>
<h3>添加品牌</h3>
<form action="/jsp-demo/updateServlet" method="post"><br>
    <%--隐藏域 提交id--%>
    <input type="hidden" name="id" value="${brand.id}">
    品牌名称：<input name="brandName" value="${brand.brandName}"><br>
    企业名称：<input name="companyName" value="${brand.companyName}"><br>
    排序：<input name="ordered" value="${brand.ordered}"><br>
    描述信息：<textarea rows="5" cols="20" name="description">${brand.description}</textarea><br>
    状态：
    <c:if test="${brand.status == 1}">
        <input type="radio" name="status" value="0">禁用
        <input type="radio" name="status" value="1" checked>启用<br>
    </c:if>
    <c:if test="${brand.status == 0}">
        <input type="radio" name="status" value="0" checked>禁用
        <input type="radio" name="status" value="1">启用<br>
    </c:if>

    <input type="submit" value="提交">
    <input type="reset" value="重置">
</form>
</body>
</html>

pom.xml

<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>4.0.0modelVersion>

  <groupId>com.wugroupId>
  <artifactId>jsp-demoartifactId>
  <version>1.0-SNAPSHOTversion>
  <packaging>warpackaging>

  <name>jsp-demo Maven Webappname>
  
  <url>http://www.example.comurl>

  <properties>
    <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    <maven.compiler.source>1.7maven.compiler.source>
    <maven.compiler.target>1.7maven.compiler.target>
  properties>

  <dependencies>
    <dependency>
      <groupId>org.mybatisgroupId>
      <artifactId>mybatisartifactId>
      <version>3.5.5version>
    dependency>
    <dependency>
      <groupId>mysqlgroupId>
      <artifactId>mysql-connector-javaartifactId>
      <version>8.0.28version>
    dependency>
    <dependency>
      <groupId>javax.servletgroupId>
      <artifactId>javax.servlet-apiartifactId>
      <version>3.1.0version>
      <scope>providedscope>
    dependency>
    <dependency>
      <groupId>jstlgroupId>
      <artifactId>jstlartifactId>
      <version>1.2version>
    dependency>
    <dependency>
      <groupId>taglibsgroupId>
      <artifactId>standardartifactId>
      <version>1.1.2version>
    dependency>
  dependencies>

  <build>
      <plugins>
        <plugin>
          <groupId>org.apache.tomcat.mavengroupId>
          <artifactId>tomcat7-maven-pluginartifactId>
          <version>2.2version>
        plugin>
        <plugin>
          <artifactId>maven-clean-pluginartifactId>
          <version>3.1.0version>
        plugin>
        
        <plugin>
          <artifactId>maven-resources-pluginartifactId>
          <version>3.0.2version>
        plugin>
        <plugin>
          <artifactId>maven-compiler-pluginartifactId>
          <version>3.8.0version>
        plugin>
        <plugin>
          <artifactId>maven-surefire-pluginartifactId>
          <version>2.22.1version>
        plugin>
        <plugin>
          <artifactId>maven-war-pluginartifactId>
          <version>3.2.2version>
        plugin>
        <plugin>
          <artifactId>maven-install-pluginartifactId>
          <version>2.5.2version>
        plugin>
        <plugin>
          <artifactId>maven-deploy-pluginartifactId>
          <version>2.8.2version>
        plugin>
      plugins>
  build>
project>