12月13日学习日志

今天学习了java web学生信息系统中从数据库展示学生信息操作。

servlet代码如下：

package com.servlet;

import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

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 com.jdbc.jdbcUtil;
import java.sql.ResultSet;

import java.sql.Connection;
import java.sql.PreparedStatement;

/**
 * Servlet implementation class list
 */
@WebServlet("/list")
public class list extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public list() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        try {
            Connection con=jdbcUtil.getcon();
            String sql="select * from stu";
            PreparedStatement pst=con.prepareStatement(sql);
            ResultSet rs=pst.executeQuery();
            List<Student> ls=new ArrayList<>();
            while(rs.next()) {
                Integer id=rs.getInt("id");
                String name=rs.getString("name");
                Integer age=rs.getInt("age");
                String num=rs.getString("num");
                Student s=new Student(id,name,age,num);
                ls.add(s);
            }
            jdbcUtil.close(con, pst, null);
            request.setAttribute("list", ls);
            request.getRequestDispatcher("list.jsp").forward(request, response);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
    }

}

其中学生信息的代码如下：

package com.servlet;

public class Student {
    private Integer id;
    private String name;
    private Integer age;
    private String num;
    public Student(Integer id, String name, Integer age, String num) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.num = num;
    }
    public Student() {
        super();
        // TODO Auto-generated constructor stub
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getNum() {
        return num;
    }
    public void setNum(String num) {
        this.num = num;
    }
    
}