JavaWeb:servlet+jsp+mybatis商品管理增删改查

JavaWeb:servlet+jsp+mybatis商品管理增删改查(2)

时间：2024-01-21 13:23:02 来源：IT袋作者：马勇

导读：JavaWeb:servlet+jsp+mybatis商品管理增删改查，功能实现 1、在 BrandMapper 接口，在接口中定义 add(Brand brand) 方法 @Insert("insert into tb_brand values (null,#{brandName},#{companyName},#{ordered},#{description},#{status});")void

JavaWeb:servlet+jsp+mybatis商品管理增删改查

JavaWeb:servlet+jsp+mybatis商品管理增删改查

功能实现

1、在 BrandMapper 接口，在接口中定义 add(Brand brand) 方法

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

2、在 BrandService 类中定义添加品牌数据方法 add(Brand brand)

public void addBrand(Brand brand) {
    SqlSession sqlSession = MyBatisUtils.openSession();
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    mapper.addBrand(brand);
    sqlSession.commit();
    sqlSession.close();
}

3、在 web 包下创建 AddServlet 的 servlet

该 servlet 的逻辑如下: 设置处理post请求乱码的字符集接收客户端提交的数据将接收到的数据封装到 Brand 对象中调用 BrandService 的 add() 方法进行添加的业务逻辑处理跳转到 selectAllServlet 资源重新查询数据

@WebServlet(value = "/addServlet")
public class AddServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Brand brand = new Brand();
        Brand brand = new Brand();
  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.setBrandName(brandName);
  brand.setCompanyName(companyName);
  brand.setOrdered(Integer.parseInt(ordered));
  brand.setDescription(description);
  brand.setStatus(Integer.parseInt(status));
            //进行添加
        BrandService brandService = new BrandService();
        brandService.addBrand(brand);
        response.sendRedirect("selectAllServlet");
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        doGet(request,response);
    }
}

但是我们可以看到上面的流程过于复杂，获取数据和添加数据太过于繁琐，所以我们可以导入一个工具类进行优化

添加依赖：

<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.3</version>
</dependency>

修改优化代码：

@WebServlet(value = "/addServlet")
public class AddServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Brand brand = new Brand();
        Map<String, String[]> parameterMap = request.getParameterMap();
        try {
            BeanUtils.populate(brand,parameterMap);
            //进行添加
            BrandService brandService = new BrandService();
            brandService.addBrand(brand);
            response.sendRedirect("selectAllServlet");
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        }
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        doGet(request,response);
    }
}

4、编写前端页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加品牌</title>
</head>
<body>
<h3>添加品牌</h3><form action="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>

2.3、修改数据回显

JavaWeb:servlet+jsp+mybatis商品管理增删改查

上图就是回显数据的效果。要实现这个效果，那当点击修改按钮时不能直接跳转到 update.jsp 页面，而是需要先带着当前行数据的 id 请求后端程序，后端程序根据 id 查询数据，将数据存储到域对象中跳转到 update.jsp 页面进行数据展示。整体流程如下

JavaWeb:servlet+jsp+mybatis商品管理增删改查

功能实现

1、编写BrandMapper方法

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

2、编写BrandService方法

在 BrandService 类中定义根据id查询数据方法 selectById(int id)

public Brand selectById(int id) {
    SqlSession sqlSession = MyBatisUtils.openSession();
    BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
    Brand brand = mapper.selectById(id);
    sqlSession.close();
    return brand;
}

3、在 web 包下创建 SelectByIdServlet 的 servlet

@WebServlet(value = "/selectByIdServlet")
public class SelectByIdServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String idStr = request.getParameter("id");
        int id = Integer.parseInt(idStr);
        BrandService brandService = new BrandService();
        Brand brand = brandService.selectById(id);
        request.setAttribute("brand",brand);
        request.getRequestDispatcher("updateBrand.jsp").forward(request,response);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        doGet(request,response);
    }
}