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JAVA的第一个项目---品牌增删改查的案例

时间：2024-11-01 19:59:53浏览次数：1  
标签：JAVA String brand req 改查 public --- import id

这几周通过对javaweb的持续学习，终于做出了第一个项目
界面比较简单，如下：

通过超链接来查询表单的所有内容

其下有新增，修改和删除三个按钮
新增页面，点击提交增加数据

修改页面用到了和新增一样的界面，通过id回显显示选中的品牌

删除键进行删除直接回到查询表单界面

项目创建分为三层架构：
1、dao层中BrandMapper进行定义初始的增删改查方法，并使用注解的方式实现对数据库的增删改查的SQL语句。
2、Service层中调用brandMapper的方法。
3、Web层中接收数据，封装brand对象等操作，然后调用Service层中的方法，最后转发到相应的jsp页面。

代码如下：
1、首先是javabeen的封装基本属性

package com.stuwhx.pojo;

/**
 * 品牌实体类
 */

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 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 +
                '}';
    }
}

mapper中定义增删改查的方法并通过注解方式定义sql语句

package com.stuwhx.mapper;

import com.stuwhx.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();

    @Insert("INSERT into tb_brand values (null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
    void add(Brand brand);

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

    /**
     * 修改
     * @param brand
     */
    @Update("update tb_brand set brand_name = #{brandName},company_name = #{companyName},ordered = #{ordered},description = #{description},status = #{status} where id = #{id}")
    void update(Brand brand);

    @Delete("delete from tb_brand where id = #{id}")
    void deleteById(int id);

}

还有与之对应的mapper.xml配置文件

<?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.stuwhx.mapper.BrandMapper">

    <resultMap id="brandResultMap" type="brand">

        <result column="brand_name" property="brandName"></result>
        <result column="company_name" property="companyName"></result>
    </resultMap>


</mapper>

2、util工具类定义获取`sqlSessionFactory工厂

package com.stuwhx.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;
    }
}

3、Service层中调用mapper的方法

package com.stuwhx.service;

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

import java.util.List;

public class BrandService {

    //调用BrandMapper.selectAll()
    SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();


    /**
     * 查询所有
     * @return
     */

        public List<Brand> selectAll(){

            //获取sqlSession对象
            SqlSession sqlSession = sqlSessionFactory.openSession();

            //获取BrandMapper对象
            BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);

            //调用方法
            List<Brand> brands = brandMapper.selectAll();

            sqlSession.close();

            return brands;


        }

    /**
     * 添加
     * @param brand
     */
    public void add(Brand brand){

            //获取sqlSession对象
            SqlSession sqlSession = sqlSessionFactory.openSession();

            //获取BrandMapper对象
            BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);

            //调用添加方法
            brandMapper.add(brand);

            //提交事务
            sqlSession.commit();
            sqlSession.close();
        }

    /**
     * 根据id查询
     * @return
     */
    public Brand selectById(int id){

        //获取sqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();

        //获取BrandMapper对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);

        //调用方法
        Brand brand = brandMapper.selectById(id);

        sqlSession.close();

        return brand;


    }

    /**
     * 修改
     * @param brand
     */
    public void update(Brand brand){

        //获取sqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();

        //获取BrandMapper对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);

        //调用添加方法
        brandMapper.update(brand);

        //提交事务
        sqlSession.commit();
        sqlSession.close();
    }

    /**
     * 根据id删除
     * @param id
     */
    public void delete(int id){
        //获取sqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();

        //获取BrandMapper对象
        BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);

        //调用添加方法
        brandMapper.deleteById(id);

        sqlSession.commit();
        sqlSession.close();
    }


}

4、Web层使用servlet获取数据并进行封装和转发
添加

package com.stuwhx.web;

import com.stuwhx.pojo.Brand;
import com.stuwhx.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 service = new BrandService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        req.setCharacterEncoding("UTF-8");

        //接受表单提交的数据，封装
        String brandName = req.getParameter("brandName");
        String companyName = req.getParameter("companyName");
        String ordered = req.getParameter("ordered");
        String description = req.getParameter("description");
        String status = req.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));

        //调用service
        service.add(brand);

        //转发到查询所有
        req.getRequestDispatcher("/selectAllServlet").forward(req,resp);

    }

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

删除

package com.stuwhx.web;

import com.stuwhx.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("/deleteServlet")
public class DeleteServlet extends HttpServlet {

    private BrandService service = new BrandService();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String id = req.getParameter("id");

        service.delete(Integer.parseInt(id));

        req.setAttribute("id",id);

        req.getRequestDispatcher("/selectAllServlet").forward(req, resp);
    }

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

修改，修改需要用id查询回显进行修改数据的显示

package com.stuwhx.web;

import com.stuwhx.pojo.Brand;
import com.stuwhx.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("/updateServlet")
public class UpdateServlet extends HttpServlet {

    private BrandService service = new BrandService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        req.setCharacterEncoding("UTF-8");

        //接受表单提交的数据，封装
        String id = req.getParameter("id");
        String brandName = req.getParameter("brandName");
        String companyName = req.getParameter("companyName");
        String ordered = req.getParameter("ordered");
        String description = req.getParameter("description");
        String status = req.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));

        //调用service
        service.update(brand);

        //转发到查询所有
        req.getRequestDispatcher("/selectAllServlet").forward(req,resp);

    }

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


package com.stuwhx.web;

import com.stuwhx.pojo.Brand;
import com.stuwhx.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("/updateServlet")
public class UpdateServlet extends HttpServlet {

    private BrandService service = new BrandService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        req.setCharacterEncoding("UTF-8");

        //接受表单提交的数据，封装
        String id = req.getParameter("id");
        String brandName = req.getParameter("brandName");
        String companyName = req.getParameter("companyName");
        String ordered = req.getParameter("ordered");
        String description = req.getParameter("description");
        String status = req.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));

        //调用service
        service.update(brand);

        //转发到查询所有
        req.getRequestDispatcher("/selectAllServlet").forward(req,resp);

    }

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

查询所有

package com.stuwhx.web;

import com.stuwhx.pojo.Brand;
import com.stuwhx.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;
import java.util.List;

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

    private BrandService service = new BrandService();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //调用BrandService对象
        List<Brand> brands = service.selectAll();

        //存入Request域中
        req.setAttribute("brands",brands);

        //转发brand.jsp
        req.getRequestDispatcher("/brand.jsp").forward(req,resp);
    }

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

前端通过jsp实现
index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>


    <a href="/brand-demo/selectAllServlet">查询所有</a>
</body>
</html>

addBrand.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>添加品牌</title>
</head>
<body>
<h3>添加品牌</h3>
<form action="/brand-demo/addServlet" method="post">
    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">
</form>
</body>
</html>

brand.jsp

<%--
  Created by IntelliJ IDEA.
  User: wuhaoxiang
  Date: 2024/10/31
  Time: 20:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<input type="button" value="新增" id = "add"><br>

<table border="1" cellspacing="0" width="80%">
    <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="/brand-demo/selectByIdServlet?id=${brand.id}">修改</a> <a href="/brand-demo/deleteServlet?id=${brand.id}">删除</a> </td>
        </tr>
    </c:forEach>
</table>

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

update.jsp

<%--
  Created by IntelliJ IDEA.
  User: wuhaoxiang
  Date: 2024/11/1
  Time: 16:23
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>修改品牌</title>
</head>
<body>
<h3>修改品牌</h3>
<form action="/brand-demo/updateServlet" method="post" >

    <!-- 隐藏域 -->
    <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="${brand.status == 0}">
        <input type="radio" name="status" value="0" checked>禁用
        <input type="radio" name="status" value="1">启用<br>
    </c:if>
    <c:if test="${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>


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

标签：JAVA,String,brand,req,改查,public,---,import,id
From： https://www.cnblogs.com/hx-top/p/18521063

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