详解JDBC实现学生管理系统

package manage;
 
import java.util.Date;
 
/**
 * @author fanxf
 * @since 2018/4/27 17:01
 */
public class Student {
 
  private int id;
 
  private int age;
 
  private String sex;
 
  private String name;
 
  private Date dateCreated;
 
  public int getId() {
    return id;
  }
 
  public void setId(int id) {
    this.id = id;
  }
 
  public int getAge() {
    return age;
  }
 
  public void setAge(int age) {
    this.age = age;
  }
 
  public String getSex() {
    return sex;
  }
 
  public void setSex(String sex) {
    this.sex = sex;
  }
 
  public String getName() {
    return name;
  }
 
  public void setName(String name) {
    this.name = name;
  }
 
  public Date getDateCreated() {
    return dateCreated;
  }
 
  public void setDateCreated(Date dateCreated) {
    this.dateCreated = dateCreated;
  }
 
  public Student() {
  }
 
  public Student(int age, String sex, String name) {
    this.age = age;
    this.sex = sex;
    this.name = name;
  }
 
  public Student(int id, int age, String sex, String name) {
    this.id = id;
    this.age = age;
    this.sex = sex;
    this.name = name;
  }
 
  @Override
  public String toString() {
    return "Student{" +
        "id=" + id +
        ", age=" + age +
        ", sex='" + sex + '\'' +
        ", name='" + name + '\'' +
        ", dateCreated=" + dateCreated +
        '}';
  }
}

package manage;
 
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
 
/**
 * @author fanxf
 * @since 2018/4/27 11:06
 */
//数据库的工具类
public class JdbcUtils {
 
  private static String driver = "";
  private static String url = "";
  private static String user = "";
  private static String password = "";
 
  static {
    Properties p = new Properties();
    try {
      p.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("db.properties"));
    } catch (IOException e) {
      e.printStackTrace();
    }
    driver = p.getProperty("driver");
    url = p.getProperty("url");
    user = p.getProperty("user");
    password = p.getProperty("password");
    try {
      Class.forName(driver);
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }
 
  public static Connection getConnection() {
    try {
      return DriverManager.getConnection(url, user, password);
    } catch (SQLException e) {
      e.printStackTrace();
    }
    return null;
  }
  //释放的时候要从小到大释放
  //Connection -> Statement --> Resultset
 
 
  public static void release(ResultSet rs, Statement stmt, Connection conn) {
    if (rs != null) {
      try {
        rs.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
    if (stmt != null) {
      try {
        stmt.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
 
    if (conn != null) {
      try {
        conn.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }
}

package manage;
 
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;
 
/**
 * @author fanxf
 * @since 2018/4/27 17:06
 */
public class ManageSystem {
 
  private static Connection conn = null;
  private static PreparedStatement ps = null;
  private static ResultSet rs = null;
 
  /**
   * 添加学生数据
   *
   * @param student
   * @return
   */
  public static int addStudent(Student student) {
    conn = JdbcUtils.getConnection();
    int result = 0;
    try {
      ps = conn.prepareStatement("INSERT INTO student (age, sex, `name`, dateCreated) VALUES (?, ?, ?, now())");
      ps.setInt(1, student.getAge()); //设置第一个参数
      ps.setString(2, student.getSex()); //设置第二个参数
      ps.setString(3, student.getName()); //设置第三个参数
      result = ps.executeUpdate();
    } catch (SQLException e) {
      e.printStackTrace();
    } finally {
      JdbcUtils.release(null, ps, conn); //关闭连接
    }
    return result;
  }
 
  public void add() {
    Scanner scan = new Scanner(System.in);
    System.out.println("请输入学生年龄");
    int age = scan.nextInt();
    System.out.println("请输入学生性别");
    String sex = scan.next();
    System.out.println("请输入学生姓名");
    String name = scan.next();
    Student s = new Student(age, sex, name);
    int flag = addStudent(s);
    if (flag > 0) {
      System.out.println("添加成功");
    } else {
      System.out.println("添加失败");
    }
  }
 
  /**
   * 修改
   *
   * @param student
   * @return
   */
  public static int updateStudent(Student student) {
    conn = JdbcUtils.getConnection();
    int result = 0;
    try {
      ps = conn.prepareStatement("UPDATE student SET age = ?, sex = ?, `name` = ? WHERE id = ?");
      ps.setInt(1, student.getAge()); //设置第一个参数
      ps.setString(2, student.getSex()); //设置第二个参数
      ps.setString(3, student.getName()); //设置第三个参数
      ps.setInt(4, student.getId());
      result = ps.executeUpdate();
    } catch (SQLException e) {
      e.printStackTrace();
    } finally {
      JdbcUtils.release(null, ps, conn); //关闭连接
    }
    return result;
  }
 
  public void update() {
    Scanner scan = new Scanner(System.in);
    System.out.println("请输入学生id");
    int id = scan.nextInt();
    System.out.println("请输入学生年龄");
    int age = scan.nextInt();
    System.out.println("请输入学生性别");
    String sex = scan.next();
    System.out.println("请输入学生姓名");
    String name = scan.next();
    Student s = new Student(id, age, sex, name);
    int flag = updateStudent(s);
    if (flag > 0) {
      System.out.println("更新成功");
    } else {
      System.out.println("更新失败");
    }
  }
 
  /**
   * 删除
   *
   * @param id
   * @return
   */
  public static int deleteStudent(int id) {
    conn = JdbcUtils.getConnection();
    int result = 0;
    try {
      ps = conn.prepareStatement("DELETE FROM student WHERE id = ?");
      ps.setInt(1, id); //设置第一个参数
      result = ps.executeUpdate();
    } catch (SQLException e) {
      e.printStackTrace();
    } finally {
      JdbcUtils.release(null, ps, conn); //关闭连接
    }
    return result;
  }
 
  public void delete() {
    Scanner scan = new Scanner(System.in);
    System.out.println("请输入学生id");
    int id = scan.nextInt();
    int flag = deleteStudent(id);
    if (flag > 0) {
      System.out.println("删除成功");
    } else {
      System.out.println("删除失败");
    }
  }
 
  public static void main(String[] args) {
    System.out.println("************ 欢迎进入学生管理系统 *************");
    ManageSystem ms = new ManageSystem();
    boolean b = true;
    while (b) {
      System.out.println("你想进行以下哪项操作");
      System.out.println("1、添加学生  2、更新学生数据  3、学生信息查询  4、删除学生 0、退出");
      Scanner scan = new Scanner(System.in);
      int i = scan.nextInt();
      switch (i) {
        case 1:
          ms.add();
          break;
        case 2:
          ms.update();
          break;
        case 3:
          System.out.println();
          break;
        case 4:
          ms.delete();
          break;
        default:
          System.out.println("没有该操作选项,请重新来过！");
          main(args);
          break;
      }
    }
  }
}