JAVAWEB elective system

According to the online tutorials and material production, the first part of information management

Source

ackage com.ischoolbar.programmer.dao;

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

import com.ischoolbar.programmer.model.Admin;
import com.ischoolbar.programmer.model.Clazz;

/**
 * 
 * @author llq
 *管理员数据库操作封装
 */
public class AdminDao extends BaseDao {
    
    public Admin login(String name ,String password){
        String sql = "select * from s_admin where name = '" + name + "' and password = '" + password + "'";
        ResultSet resultSet = query(sql);
        try {
            if(resultSet.next()){
                Admin admin = new Admin();
                admin.setId(resultSet.getInt("id"));
                admin.setName(resultSet.getString("name"));
                admin.setPassword(resultSet.getString("password"));
                admin.setStatus(resultSet.getInt("status"));
                return admin;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    public boolean editPassword(Admin admin,String newPassword) {
        // TODO Auto-generated method stub
        String sql = "update s_admin set password = '"+newPassword+"' where id = " + admin.getId();
        return update(sql);
    }
}

Package com.ischoolbar.programmer.dao; 

Import the java.sql.Connection;
 Import java.sql.PreparedStatement;
 Import the java.sql.ResultSet;
 Import java.sql.SQLException;
 Import of java.util.ArrayList;
 Import java.util.List ; 

Import com.ischoolbar.programmer.util.DbUtil; 

/ ** 
 * 
 * @author LLQ 
 * DAO basis, the basic operation of the package 
 * / 
public  class BaseDao {
     Private DbUtil DBUtil = new new DbUtil (); 
    
    / ** 
     * close the connection, free up resources 
     * / 
    public  voidcloseCon () { 
        dbUtil.closeCon (); 
    } 
    
    / ** 
     * based queries, multiple queries 
     * / 
    public the ResultSet Query (String SQL) {
         the try { 
            the PreparedStatement the prepareStatement = dbUtil.getConnection () the prepareStatement (SQL);.
             return the prepareStatement. the executeQuery (); 
            
        } the catch (SQLException E) {
             // the TODO Auto-Generated Block the catch 
            e.printStackTrace (); 
        } 
        return  null ; 
    } 
    / ** 
     * changing the contents of database operations 
     * / 
    public  Boolean update(String sql){
        try {
            return dbUtil.getConnection().prepareStatement(sql).executeUpdate() > 0;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }
    public Connection getConnection(){
        return dbUtil.getConnection();
    }
}

package com.ischoolbar.programmer.dao;

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

import com.ischoolbar.programmer.model.Admin;
import com.ischoolbar.programmer.model.Clazz;
import com.ischoolbar.programmer.model.Page;
import com.ischoolbar.programmer.model.Student;
import com.ischoolbar.programmer.util.StringUtil;

public class StudentDao extends BaseDao {
    public boolean addStudent(Student student){
        String sql = "insert into s_student values(null,'"+student.getSn()+"','"+student.getName()+"'";
        sql += ",'" + student.getPassword() + "'," + student.getClazzId();
        sql += ",'" + student.getSex() + "','" + student.getMobile() + "'";
        sql += ",'" + student.getQq() + "',null)";
        return update(sql);
    }
    public boolean editStudent(Student student) {
        // TODO Auto-generated method stub
        String sql = "update s_student set name = '"+student.getName()+"'";
        sql += ",sex = '" + student.getSex() + "'";
        sql += ",mobile = '" + student.getMobile() + "'";
        sql += ",qq = '" + student.getQq() + "'";
        sql += ",clazz_id = " + student.getClazzId();
        sql += " where id = " + student.getId();
        return update(sql);
    }
    public boolean setStudentPhoto(Student student) {
        // TODO Auto-generated method stub
        String sql = "update s_student set photo = ? where id = ?";
        Connection connection = getConnection();
        try {
            PreparedStatement prepareStatement = connection.prepareStatement(sql);
            prepareStatement.setBinaryStream(1, student.getPhoto());
            prepareStatement.setInt(2, student.getId());
            return prepareStatement.executeUpdate() > 0;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return update(sql);
    }
    public boolean deleteStudent(String ids) {
        // TODO Auto-generated method stub
        String sql = "delete from s_student where id in("+ids+")";
        return update(sql);
    }
    public Student getStudent(int id){
        String sql = "select * from s_student where id = " + id;
        Student student = null;
        ResultSet resultSet = query(sql);
        try {
            if(resultSet.next()){
                student = new Student();
                student.setId(resultSet.getInt("id"));
                student.setClazzId(resultSet.getInt("clazz_id"));
                student.setMobile(resultSet.getString("mobile"));
                student.setName(resultSet.getString("name"));
                student.setPassword(resultSet.getString("password"));
                student.setPhoto(resultSet.getBinaryStream("photo"));
                student.setQq(resultSet.getString("qq"));
                student.setSex(resultSet.getString("sex"));
                student.setSn(resultSet.getString("sn"));
                return student;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return student;
    }
    public List<Student> getStudentList(Student student,Page page){
        List<Student> ret = new ArrayList<Student>();
        String sql = "select * from s_student ";
        if(!StringUtil.isEmpty(student.getName())){
            sql += "and name like '%" + student.getName() + "%'";
        }
        if(student.getClazzId() != 0){
            sql += " and clazz_id = " + student.getClazzId();
        }
        if(student.getId() != 0){
            sql += " and id = " + student.getId();
        }
        sql += " limit " + page.getStart() + "," + page.getPageSize();
        ResultSet resultSet = query(sql.replaceFirst("and", "where"));
        try {
            while(resultSet.next()){
                Student s = new Student();
                s.setId(resultSet.getInt("id"));
                s.setClazzId(resultSet.getInt("clazz_id"));
                s.setMobile(resultSet.getString("mobile"));
                s.setName(resultSet.getString("name"));
                s.setPassword(resultSet.getString("password"));
                s.setPhoto(resultSet.getBinaryStream("photo"));
                s.setQq(resultSet.getString("qq"));
                s.setSex(resultSet.getString("sex"));
                s.setSn(resultSet.getString("sn"));
                ret.add(s);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return ret;
    }
    public int getStudentListTotal(Student student){
        int total = 0;
        String sql = "select count(*)as total from s_student ";
        if(!StringUtil.isEmpty(student.getName())){
            sql += "and name like '%" + student.getName() + "%'";
        }
        if(student.getClazzId() != 0){
            sql += " and clazz_id = " + student.getClazzId();
        }
        if(student.getId() != 0){
            sql += " and id = " + student.getId();
        }
        ResultSet resultSet = query(sql.replaceFirst("and", "where"));
        try {
            while(resultSet.next()){
                total = resultSet.getInt("total");
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return total;
    }

package com.ischoolbar.programmer.util;

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;

import javax.management.loading.PrivateClassLoader;
/**
 * 
 * @author llq
 *数据库连util
 */
public class DbUtil {

    private String dbUrl = "jdbc:mysql://localhost:3306/db_student_manager_web?useUnicode=true&characterEncoding=utf8";
    private String dbUser = "root";
    private String dbPassword = "";
    private String jdbcName = "com.mysql.jdbc.Driver";
    private Connection connection = null;
    public Connection getConnection(){
        try {
            Class.forName(jdbcName);
            connection = DriverManager.getConnection(dbUrl, dbUser, dbPassword);
            System.out.println("数据库链接成功！");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            System.out.println("数据库链接失败！");
            e.printStackTrace();
        }
        return connection;
    }
    
    public void closeCon(){
        if(connection != null)
            try {
                connection.close();
                System.out.println("数据库链接已关闭！");
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    }
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        DbUtil dbUtil = new DbUtil();
        dbUtil.getConnection();
    }

}

JAVAWEB elective system

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