Java学习12.15

javaweb数据库增删改查——学生成绩管理系统

1.bean层

studentInfo.java

package bean;

public class studentInfo {
    private String IDnumber;
    private String name;
    private String socre;
    private String classroom;
    private String major;
    public String getIDnumber() {
        return IDnumber;
    }
    public void setIDnumber(String iDnumber) {
        IDnumber = iDnumber;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    
    public String getClassroom() {
        return classroom;
    }
    public void setClassroom(String classroom) {
        this.classroom = classroom;
    }
    public String getMajor() {
        return major;
    }
    public void setMajor(String major) {
        this.major = major;
    }
    
    public studentInfo() {
        
    }
    public String getSocre() {
        return socre;
    }
    public void setSocre(String socre) {
        this.socre = socre;
    }
    public studentInfo(String iDnumber, String name, String socre, String classroom, String major) {
        super();
        IDnumber = iDnumber;
        this.name = name;
        this.socre = socre;
        this.classroom = classroom;
        this.major = major;
    }
    
    public void setstudentInfo(String iDnumber, String name, String socre, String classroom, String major) {
        
        IDnumber = iDnumber;
        this.name = name;
        this.socre = socre;
        this.classroom = classroom;
        this.major = major;
    }
    @Override
    public String toString() {
        return "student [IDnumber=" + IDnumber + ", name=" + name + ", socre=" + socre + ", classroom=" + classroom
                + ", major=" + major + ", getIDnumber()=" + getIDnumber() + ", getName()=" + getName()
                + ", getClassroom()=" + getClassroom() + ", getMajor()=" + getMajor() + ", getSocre()=" + getSocre()
                + "]";
    }
    

}

2.dao层

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import bean.DButil;
import bean.studentInfo;

public class dao {
    
    public studentInfo getbyname(String name) {
        String sql = "select * from studentinformation"+ " where name ='" + name + "'";
        Connection conn = DButil.getCon();
        Statement state = null;
        ResultSet rs = null;
        studentInfo book=new studentInfo();
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
     
                String IDnumber=rs.getString("IDnumber");
                String Name = rs.getString("name");
                String major = rs.getString("major");
                String score = rs.getString("score");
                String classroom=rs.getString("classroom");
                book.setstudentInfo(IDnumber,Name,score,classroom,major);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DButil.close(rs, state, conn);
        }
        
        return book;
    }

   //增加学生对象
    public boolean add(studentInfo stu) {
        Connection conn = DButil.getCon();
        PreparedStatement pstmt = null;
        boolean f = false;
        int a = 0;
        try {
            String sql = "insert into studentinformation(name,IDnumber,score,classroom,major) value(?,?,?,?,?)";
            
            
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, stu.getName());
            pstmt.setString(2, stu.getIDnumber());
            pstmt.setString(3, stu.getSocre());
            pstmt.setString(4, stu.getClassroom());
            pstmt.setString(5, stu.getMajor());
            
            a = pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DButil.close(pstmt, conn);
        }
        if (a > 0)
            f = true;

        return f;
        
    
    }

    //删除学生对象
     public boolean delete(String name)
     {
         String sql="delete from studentinformation "+"where name='" + name + "'";
         
         Connection conn = DButil.getCon();
         Statement state = null;
         int a = 0;
         boolean f = false;
         try {
             state = conn.createStatement();
             a = state.executeUpdate(sql);
         } catch (SQLException e) {
             e.printStackTrace();
         } finally {
             DButil.close(state, conn);
         }
         
         if (a > 0) {
             f = true;
         }
         return f;
     }
     
     //修改分数
    public boolean update(studentInfo stu) {
        System.out.println(stu.getSocre());
        
        String sql = "update studentinformation set score='"+ stu.getSocre() + "',classroom='" 
                      + stu.getClassroom()+ "',major='"+stu.getMajor()+"' where name='"+stu.getName()+"'";
        Connection conn = DButil.getCon();
        Statement state = null;
        boolean f = false;
        int a = 0;
        try {
            state = conn.createStatement();
            System.out.println("看看是不是执行了");
            a = state.executeUpdate(sql);
            System.out.println(a);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DButil.close(state, conn);
        }

        if (a > 0) {
            f = true;
        }
        System.out.println(f);
        return f;
        
        
        
        
    }

    
   //浏览学生信息
    public List<studentInfo> list() {
        String sql = "select * from studentinformation";
        List<studentInfo> list = new ArrayList<>();
        Connection conn = DButil.getCon();
        Statement state = null;
        ResultSet rs = null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            studentInfo bean = null;
            while (rs.next()) {
                
                String IDnumber=rs.getString("IDnumber");
                String Name = rs.getString("name");
                String major = rs.getString("major");
                String score = rs.getString("score");
                String classroom=rs.getString("classroom");
                bean = new studentInfo(IDnumber,Name,score,classroom,major);
                list.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DButil.close(rs, state, conn);
        }

        return list;
    }
    
    //模糊查询学生成绩
    public List<studentInfo> search(String IDnumber,String Name)
    {
        System.out.println(IDnumber+Name);
        String sql = "select * from studentinformation where (name like '%"+Name+"%' and IDnumber like '%"+IDnumber+"%')";
       
        List<studentInfo> list = new ArrayList<>();
        Connection conn = DButil.getCon();
        Statement state = null;
        ResultSet rs = null;
        studentInfo bean = null;
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                String classroom = rs.getString("classroom");
                String major = rs.getString("major");
                String score = rs.getString("score");
                bean = new studentInfo(IDnumber,Name,score,classroom,major);
               
                list.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DButil.close(rs, state, conn);
        }
        
        return list;
    }
    
    
    

}

3.DBUtil层

package DBUtil;

import java.sql.Connection;
import java.sql.DriverManager;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class DButil {
    private static String mysqlname = "studentgrade";
    private static Connection con;
    private static Statement sta;
    private static ResultSet re;
    private static String coursename = "com.mysql.cj.jdbc.Driver";
    private static String url = "jdbc:mysql://localhost:3306/"+mysqlname+"?serverTimezone=UTC";
    
    //注册驱动
    public static Connection getCon() {
        try {
            Class.forName(coursename);
            System.out.println("驱动加载成功");
        }catch(ClassNotFoundException e) {
            e.printStackTrace();
        }
        try {
            con = DriverManager.getConnection(url,"root","123asd..00");
            System.out.println("连接成功");
        }catch(Exception e){
            e.printStackTrace();
            con = null;
        }
        return con;
    }
    
    public static void close (Statement state, Connection conn) {
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close (ResultSet rs, Statement state, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    public static void main(String[] args)
    {
        getCon();
    }
}