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项目简介

1.四层架构的模型图

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

2.过程

  1.创立数据库(创立表)
  2.导入需求的jar包(导入WebContent目录下的WEB-INF下的bin目录里面)
  3.创立包:  com.yfh.pojo(装实体类)
             com.yfh.web(装dao类
             com.yfh.service(装service类
             com.yfh.servlet(装servlet类)
             com.yfh.util(装东西类)
  4.创立JDBC东西类(运用Druid数据库连接池
  5.装备数据库及连接池参数(放于src下)
  6.实体类层:用来封装属性及其get set办法 toString办法,有参结构办法,无参结构办法等。
  7.Dao层:对数据库的增删改查办法的封装(操作数据库)也是属于事务逻辑
  8.Servlet(Controller):流程操控
  9.Service:处理事务逻辑
  10.jsp(View)页面(坐落WebContent目录下)

项目完结

项目包预览

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

环境搭建

创立新的模块 brand_demo,并在 pom.xml 文件引入坐标
<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.example</groupId>
  <artifactId>brand-demo</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>brand-demo Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.34</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.5</version>
    </dependency>
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>
  </dependencies>
  <build>
    <finalName>brand-demo</finalName>
  </build>
</project>
com.yfh 包下创立三层架构包结构,并将创立(若现成的则导入)数据库表 tb_brand

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

com.yfh.pojo 包下创立实体类 Brand
/**
* 品牌实体类
*/
public class Brand {
    // id 主键
    private Integer id;
    // 品牌称号
    private String brandName;
    // 企业称号
    private String companyName;
    // 排序字段
    private Integer ordered;
    // 描绘信息
    private String description;
    // 状况:0:禁用  1:启用
    private Integer status;
    public Brand() {
    }
    public Brand(Integer id, String brandName, String companyName, String description) {
        this.id = id;
        this.brandName = brandName;
        this.companyName = companyName;
        this.description = description;
    }
    public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {
        this.id = id;
        this.brandName = brandName;
        this.companyName = companyName;
        this.ordered = ordered;
        this.description = description;
        this.status = 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;
    }
    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 +
            '}';
    }
}

预备 MyBatis 基础环境

com.yfh.mapper 创立 BrandMapper
public interface BrandMapper {
}
resources 文件夹下增加 Mybatis-config.xml
<?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.yfh.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:///test?useSSL=false&amp;useServerPrepStmts=true"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <package name="com.yfh.mapper"/>
  </mappers>
</configuration>
resources 文件夹下创立 com.yfh.mapper 包,并在该包下创立 BrandMapper.xml
<?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.yfh.mapper.BrandMapper">
    <resultMap id="brandResultMap" type="brand">
        <result column="brand_name" property="brandName"></result>
        <result column="company_name" property="companyName"></result>
    </resultMap>
</mapper>

查询一切功用完结

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

完结 Dao 层,经过 select * from tb_brand 完结查询表中的一切内容
public interface BrandMapper {
    /**
* 查询一切
* @return
*/
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List<Brand> selectAll();
}
在完结 Service 层之前将 SqlSessionFactory 类导入到 com.yfh.util 包下
public class SqlSessionFactoryUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        //静态代码块会随着类的加载而主动履行,且只履行一次
        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;
    }
}
完结 Service 层,创立 BrandService 类,完结查询一切的逻辑功用 (根本过程:树立sql会话,经过sql会话获取mapper目标,最终调用存储在一个变量后回来,留意查询完之后一定要封闭会话)
/**
  * 查询一切
  * @return
  */
public List<Brand> selectAll(){
    //调用BrandMapper.selectAll()
	SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    //1.获取SqlSession
    SqlSession sqlSession = factory.openSession();
    //2.获取BrandMapper
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    //3.调用办法
    List<Brand> brands = mapper.selectAll();
    sqlSession.close();
    return brands;
}
完结 web 层之写好 index.html 页面
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Title</title>
  </head>
  <body>
    <a href="/brand-demo/selectAllServlet">查询一切</a>
  </body>
</html>
完结 web 层之完结 SelectAllServlet 类完结页面交互
@WebServlet("/selectAllServlet")
    public class SelectAllServlet extends HttpServlet {
        private BrandService service = new BrandService();
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //1. 调用BrandService完结查询
            List<Brand> brands = service.selectAll();
            //2.存入request域中
            request.setAttribute("brands",brands);
            //3.转发到brand.jsp
            request.getRequestDispatcher("/brand.jsp").forward(request,response);
        }
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doGet(request,response);
        }
    }
完结 web 层之在 webapp 包下完结 brand.jsp 页面
<%--
  Created by IntelliJ IDEA.
  User: yy
  Date: 2023/1/10
  Time: 00:41
  To change this template use File | Settings | File Templates.
--%>
<%@ 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>Title</title>
</head>
<body>
<a href="addBrand.jsp">
    <button>新增</button>
</a>
<hr>
<table border="1" cellpadding="0" width="100%" align="center">
    <tr align="center">
        <td>序号</td>
        <td>品牌称号</td>
        <td>企业称号</td>
        <td>排序</td>
        <td>品牌介绍</td>
        <td>状况</td>
        <td>操作</td>
    </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="/selectByIdServlet?id=${brand.id}">修改</a> <a href="/deleteByIdServlet?id=${brand.id}">删去</a></td>
        </tr>
    </c:forEach>
</table>
</body>
</html>
查询一切页面作用

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

增加数据功用完结

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

完结 Dao 层,经过 insert into tb_brand values(null,brand_name,company_name,ordered,description,status) 完结增加数据
public interface BrandMapper {
    /**
* 增加数据
* @param brand
*/
    @Insert("insert into tb_brand values(null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
    void add(Brand brand);
}
完结 Service 层,在 BrandService 类,完结查询一切的逻辑功用 (根本过程:树立sql会话,经过sql会话获取mapper目标,最终调用并commit,留意查询完之后一定要封闭会话)
/**
  * 增加数据
  * @param brand
  */
public void add(Brand brand){
    //调用BrandMapper.selectAll()
	SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    //1.获取SqlSession
    SqlSession sqlSession = factory.openSession();
    //2.获取brandMapper
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    //3.调用办法
    mapper.add(brand);
    sqlSession.commit();
    sqlSession.close();
}
完结 web 层之在 brand.jsp 的头部增加增加 按钮
<input type="button" value="新增" id="add"><br>
完结 web 层之在 brand.jsp 的下面完结增加按钮的 js 脚本
<script>
    document.getElementById("add").onclick = function (){
        location.href = "/brand-demo/addBrand.jsp";
    }
</script>
完结 web 层之写好 addBrand.jsp 页面
<%--
  Created by IntelliJ IDEA.
  User: yy
  Date: 2023/1/10
  Time: 13:52
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>增加品牌</title>
</head>
<body>
    <h3>增加品牌</h3>
    <form action="/addServlet" method="post">
        品牌称号:<input type="text" name="brandName"> <br>
        企业称号:<input type="text" name="companyName"> <br>
        排序:<input type="number" name="ordered"> <br>
        描绘信息:<textarea name="description" rows="1" cols="20"></textarea> <br>
        状况:
        <input type="radio" name="status" value="0"> 禁用
        <input type="radio" name="status" value="1"> 启用 <br>
        <button type="submit">提交</button>
    </form>
</body>
</html>
完结 web 层之完结 AddServlet 类完结页面交互
@WebServlet("/addServlet")
    public class AddServlet extends HttpServlet {
        private BrandService service = new BrandService();
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //处理POST恳求的编码处理问题
            request.setCharacterEncoding("utf-8");
            //1.接纳表单提交的数据,封装为一个Brand目标
            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.setBrandName(brandName);
            brand.setCompanyName(companyName);
            brand.setOrdered(Integer.parseInt(ordered));
            brand.setDescription(description);
            brand.setStatus(Integer.parseInt(status));
            //2.调用Service,完结增加
            service.add(brand);
            //3.转发到查询一切Servlet
            request.getRequestDispatcher("selectAllServlet").forward(request,response);
        }
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doGet(request,response);
        }
    }
增加数据页面作用

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)
JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

修正数据功用完结

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

回显数据
完结 Dao 层,经过 select * from tb_brand where id=#{id} 完结增加数据
public interface BrandMapper {
    /**
* 根据id查询
* @param id
* @return
*/
    @Select("select * from tb_brand where id=#{id}")
    @ResultMap("brandResultMap")
    Brand selectById(int id);
}
完结 Service 层,创立 BrandService 类,完结根据id查询逻辑功用 (根本过程:树立sql会话,经过sql会话获取mapper目标,最终调用存储在一个变量后回来,留意查询完之后一定要封闭会话)
/**
 * 根据id查询
 * @param id
 * @return
 */
public Brand selectById(int id){
    //调用BrandMapper.selectById(id)
    SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    //1.获取SqlSession
    SqlSession sqlSession = factory.openSession();
    //2.获取BrandMapper
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    //3.调用办法
    Brand brand = mapper.selectById(id);
    sqlSession.close();
    return brand;
}
修正数据

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

完结 Dao 层,经过 update tb_brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description},status=#{status} where id=#{id} 完结修正数据
@Update("update tb_brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description},status=#{status} where id=#{id}")
@ResultMap("brandResultMap")
void update(Brand brand);
完结 Service 层,创立 BrandService 类,调用修正数据功用 (根本过程:树立sql会话,经过sql会话获取mapper目标,留意查询完之后一定要封闭会话)
/**
 * 修正数据
 * @param brand
 */
public void update(Brand brand){
    //调用BrandMapper.update(brand)
	SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    //1. 获取SqlSession
    SqlSession sqlSession = factory.openSession();
    //2.获取BrandMapper
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    //3.调用办法
    mapper.update(brand);
    sqlSession.commit();
    sqlSession.close();
}
完结 web 层之在 brand.jsp 页面把修正链接增加链接地址
完结 web 层之在 brand.jsp 页面把修正链接增加链接地址
完结 web 层之在 updata.jsp 页面回显数据,留意回显的数据回传回id,需求把id隐藏起来,这是不需求展现给用户来看的;
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: yy
  Date: 2023/1/10
  Time: 15:17
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>修改</title>
</head>
<body>
<h3>修改品牌</h3>
<form action="/upDateServlet" method="post">
    <input type="text" name="id" value="${brand.id}">
    品牌称号:<input type="text" name="brandName" value="${brand.brandName}"> <br>
    企业称号:<input type="text" name="companyName" value="${brand.companyName}"> <br>
    排序:<input type="text" name="ordered" value="${brand.ordered}"> <br>
    描绘信息:<textarea name="description" rows="1" cols="20">${brand.description}</textarea> <br>
    状况:
   <c:if test="${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>
    <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>
    <button type="submit">提交</button>
</form>
</body>
</html>
完结 web 层之完结 UpdateServlet 类完结页面交互
@WebServlet("/updateServlet")
    public class UpdateServlet extends HttpServlet {
        private BrandService service = new BrandService();
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //处理POST恳求的编码处理问题
            request.setCharacterEncoding("utf-8");
            //1.接纳表单提交的数据,封装为一个Brand目标
            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));
            //2.调用Service,完结修正
            service.update(brand);
            //3.转发到SelectAllServlet
            request.getRequestDispatcher("selectAllServlet").forward(request,response);
        }
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            this.doGet(request,response);
        }
    }
删去数据(额外增加的功用)

JavaWeb 品牌管理系统  (四层架构模型实现品牌增删改查)

完结 Dao 层,经过 delete from tb_brand where id=#{id} 完结删去数据
/**
  * 根据id删去数据
  * @param id
  */
@Delete("delete from tb_brand where id=#{id}")
@ResultMap("brandResultMap")
void deleteById(int id);
完结 Service 层,创立 BrandService 类,调用删去数据功用 (根本过程:树立sql会话,经过sql会话获取mapper目标,留意查询完之后一定要封闭会话)
/**
 * 根据id删去数据
 * @param id
 */
public void delete(int id){
    //调用BrandMapper.delete(id)
	SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    //1.获取SqlSession
    SqlSession sqlSession = factory.openSession();
    //2.获取BrandMapper
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    //3.调用办法
    mapper.deleteById(id);
    sqlSession.commit();
    sqlSession.close();
}
完结 web 层之在 brand.jsp 页面把删去链接增加链接地址
<a href="/brand-demo/deleteByIdServlet?id=${brand.id}">删去</a>
完结 web 层之完结 DeleteByIdServlet 类完结页面交互
@WebServlet("/deleteByIdServlet")
public class DeleteByIdServlet extends HttpServlet {
    private BrandService service = new BrandService();
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.接纳需求删去数据的id
        String id = request.getParameter("id");
        //2.调用Service
        service.delete(Integer.parseInt(id));
        //3.转发至SelectAllServlet
        request.getRequestDispatcher("selectAllServlet").forward(request,response);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}