JavaWeb小项目（二）- 完成品牌数据的增删改查（JSP/MVC/三层架构综合应用）

文章目录

JavaWeb小项目（二）- 完成品牌数据的增删改查（JSP/MVC/三层架构综合应用）
- 环境搭建
- 查询所有
- 添加数据
- 修改数据
- - 回显数据
  - 修改数据
- 删除数据（额外添加的功能）

涉及技术栈：Java，MyBatis，Servlet，JSP
需要自行导入的包链接：提取码：6666

环境搭建

创建新的模块 brand_demo，并在 pom.xml 文件引入坐标


        
        
            org.mybatis
            mybatis
            3.5.5
        

        
        
            mysql
            mysql-connector-java
            5.1.46
        

        
        
            javax.servlet
            javax.servlet-api
            3.1.0
            provided
        

        
        
            javax.servlet.jsp
            jsp-api
            2.2
            provided
        

        
        
            jstl
            jstl
            1.2
        
        
            taglibs
            standard
            1.1.2
        
    


    
        
            
                org.apache.tomcat.maven
                tomcat7-maven-plugin
                2.2

在 com.itheima 包下创建三层架构的包结构，并将创建（若现成的则导入）数据库表 tb_brand

在 com.itheima.pojo 包下创建实体类 Brand

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 +
                '}';
    }
}

准备 MyBatis 基础环境
在 com.itheima.mapper 创建 BrandMapper

public interface BrandMapper {
}

在 resources 文件夹下添加 Mybatis-config.xml

在 resources 文件夹下创建 com.itheima.mapper 包，并在该包下创建 BrandMapper.xml

查询所有

实现 Dao 层，通过 select * from tb_brand 实现查询表中的所有内容

public interface BrandMapper {

    
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List selectAll();
}

在实现 Service 层之前将 SqlSessionFactory 类导入到 com.itheima.util 包下

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;
    }
}

实现 Service 层，创建 BrandService 类，实现查询所有的逻辑功能（基本步骤：建立sql会话，通过sql会话获取mapper对象，最后调用存储在一个变量后返回，注意查询完之后一定要关闭会话）；

public List 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.调用方法
    List brands = mapper.selectAll();
    sqlSession.close();
    return brands;
}

实现 web 层之写好 index.html 页面




    
    Title



    查询所有

实现 web 层之实现 SelectAllServlet 类实现页面交互

@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完成查询
        List 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);
    }
}

实现 web 层之在 webapp 包下实现 brand.jsp 页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>




    
    Title






        
                
                
    
        序号
        品牌名称
        企业名称
        排序
        品牌介绍
        状态
        操作
    
    
            ${brand.id}
            ${brand.brandName}
            ${brand.companyName}
            ${brand.ordered}
            ${brand.description}
            启用
            
            禁用
            
            修改 删除

实验效果

序号	品牌名称	企业名称	排序	品牌介绍	状态	操作
${brand.id}	${brand.brandName}	${brand.companyName}	${brand.ordered}	${brand.description}	启用	禁用	修改删除

添加数据

实现 Dao 层，通过 insert into tb_brand values(null,brand_name,company_name,ordered,description,status) 实现添加数据

public interface BrandMapper {

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

实现 Service 层，在 BrandService 类，实现查询所有的逻辑功能（基本步骤：建立sql会话，通过sql会话获取mapper对象，最后调用并commit，注意查询完之后一定要关闭会话）；

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.调用方法
    mapper.add(brand);
    sqlSession.commit();
    sqlSession.close();
}

实现 web 层之在 brand.jsp 的头部添加添加 “按钮”

实现 web 层之在 brand.jsp 的下面实现添加按钮的 js 脚本

实现 web 层之写好 addBrand.jsp 页面

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




    
    添加品牌


添加品牌

    品牌名称：

    企业名称：

    排序：

    描述信息：

    状态：
    禁用
    启用

实现 web 层之实现 AddServlet 类实现页面交互

@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请求的编码处理问题
        request.setCharacterEncoding("utf-8");

        //1.接收表单提交的数据，封装为一个Brand对象
        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，完成添加
        service.add(brand);

        //3.转发到查询所有Servlet
        request.getRequestDispatcher("selectAllServlet").forward(request,response);
    }

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

实验结果

修改数据回显数据

实现 Dao 层，通过 select * from tb_brand where id=#{id} 实现添加数据

public interface BrandMapper {

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

实现 Service 层，创建 BrandService 类，实现根据id查询逻辑功能（基本步骤：建立sql会话，通过sql会话获取mapper对象，最后调用存储在一个变量后返回，注意查询完之后一定要关闭会话）；

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.调用方法
    Brand brand = mapper.selectById(id);
    sqlSession.close();
    return brand;
}

修改数据

实现 Dao 层，通过 update tb_brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description},status=#{status} where id=#{id} 实现修改数据

@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);

实现 Service 层，创建 BrandService 类，调用修改数据功能（基本步骤：建立sql会话，通过sql会话获取mapper对象，注意查询完之后一定要关闭会话）；

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.调用方法
    mapper.update(brand);
    sqlSession.commit();
    sqlSession.close();
}

实现 web 层之在 brand.jsp 页面把修改链接添加链接地址
```
修改
```

实现 web 层之在 selectById.jsp 页面回显数据，注意回显的数据回传回id，需要把id隐藏起来，这是不需要展现给用户来看的；

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>




    
    修改品牌


修改品牌

    

    品牌名称：

    企业名称：

    排序：

    描述信息：${brand.description}

    状态：
    
        禁用
        启用

实现 web 层之实现 UpdateServlet 类实现页面交互

@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请求的编码处理问题
        request.setCharacterEncoding("utf-8");

        //1.接收表单提交的数据，封装为一个Brand对象
        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，完成修改
        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);
    }
}

删除数据（额外添加的功能）

实现 Dao 层，通过 delete from tb_brand where id=#{id} 实现删除数据

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

实现 Service 层，创建 BrandService 类，调用删除数据功能（基本步骤：建立sql会话，通过sql会话获取mapper对象，注意查询完之后一定要关闭会话）；

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.调用方法
    mapper.deleteById(id);
    sqlSession.commit();
    sqlSession.close();
}

实现 web 层之在 brand.jsp 页面把删除链接添加链接地址
```
删除
```

实现 web 层之实现 DeleteByIdServlet 类实现页面交互

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

    private BrandService service = new BrandService();

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

        //1.接收需要删除数据的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);
    }
}

JavaWeb小项目（二）- 完成品牌数据的增删改查（JSP/MVC/三层架构综合应用）

添加品牌

修改品牌

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