使用Servlet修改水果库存系统,并使用PostMan测试Servlet请求

 <packaging>war</packaging>
 <dependencies>
    <dependency>
      <groupId>jakarta.servlet</groupId>
      <artifactId>jakarta.servlet-api</artifactId>
      <version>6.0.0</version>
    </dependency>

    <dependency>
      <groupId>com.csdn</groupId>
      <artifactId>pro03-fruit-optimize</artifactId>
      <version>1.0-SNAPSHOT</version>
    </dependency>
 </dependencies>

• pro03-fruit-optimize是我自己封装的一个jar包，功能是可以实现水果系统的增删改查

1、查询水果清单IndexServlet

package com.csdn.fruit.servlet;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dao.impl.FruitDaoImpl;
import com.csdn.fruit.pojo.Fruit;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
@WebServlet("/index")
public class IndexServlet extends HttpServlet {

    private FruitDao fruitDao = new FruitDaoImpl();

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<Fruit> fruitList = fruitDao.getFruitList();
        fruitList.stream().forEach(System.out::println);
    }
}

• 这里面的FruitDao水果数据访问对象接口，FruitDaoImpl水果数据访问对象实现类，都在pro03-fruit-optimize这个jar包里面

2、通过水果名查询水果EditServlet

package com.csdn.fruit.servlet;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dao.impl.FruitDaoImpl;
import com.csdn.fruit.pojo.Fruit;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/edit")
public class EditServlet extends HttpServlet {

    FruitDao fruitDao = new FruitDaoImpl();

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String fname = req.getParameter("fname");
        Fruit fruit = fruitDao.getFruitByFname(fname);
        System.out.println(fruit);
    }
}

3、 根据水果名修改库存量UpdateServlet

package com.csdn.fruit.servlet;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dao.impl.FruitDaoImpl;
import com.csdn.fruit.pojo.Fruit;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/update")
public class UpdateServlet extends HttpServlet {

    private FruitDao fruitDao = new FruitDaoImpl();

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //String fidStr = req.getParameter("fid");
        //Integer fid = Integer.parseInt(fidStr);
        String fname = req.getParameter("fname");
        //Integer price = Integer.parseInt(req.getParameter("price"));
        Integer fcount = Integer.parseInt(req.getParameter("fcount"));
        //String remark = req.getParameter("remark");

        fruitDao.updateFruit(new Fruit(0,fname, 0, fcount, null));
        System.out.println("修改成功");
    }
}

• 因为我底层也就是FruitDaoImpl写的就是通过水果名，修改水果的库存量，所以这里只能修改库存量fcount

String sql = "update  t_fruit set fcount=? where fname = ?";

4、根据水果名删除水果记录DelServlet

package com.csdn.fruit.servlet;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dao.impl.FruitDaoImpl;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/del")
public class DelServlet extends HttpServlet {

    FruitDao fruitDao = new FruitDaoImpl();

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String fname = req.getParameter("fname");
        fruitDao.delFruit(fname);
        System.out.println("删除成功！");

    }
}

5、添加水果AddServlet

package com.csdn.fruit.servlet;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dao.impl.FruitDaoImpl;
import com.csdn.fruit.pojo.Fruit;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/add")
public class AddServlet extends HttpServlet {

    private FruitDao fruitDao = new FruitDaoImpl();

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String fname = req.getParameter("fname");
        Integer price = Integer.parseInt(req.getParameter("price"));
        Integer fcount = Integer.parseInt(req.getParameter("fcount"));
        String remark = req.getParameter("remark");

        Fruit fruit = new Fruit(fname, price, fcount, remark);
        fruitDao.addFruit(fruit);

        System.out.println("添加成功！");
    }
}

• 注意：这里面的 Post 请求，要把 enctype 的值调成 x-www-form-urlencoded