**//java之jdbc+DAO实现学生信息的增删改**

//java之jdbc学生信息的增删改
//先建立学生类和成绩类

package USEBEAN;public class Grade {    private int id;    private int grade;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public int getGrade() {    return grade;    }    public void setGrade(int grade) {        this.grade = grade;    }}

//—————————————

package USEBEAN;public class Student {private int id;private String name;private int age;private int grade;public int getGrade() {    return grade;}public void setGrade(int grade) {    this.grade = grade;}public int getId() {    return id;}public void setId(int id) {    this.id = id;}public String getName() {    return name;}public void setName(String name) {    this.name = name;}public int getAge() {    return age;}public void setAge(int age) {    this.age = age;}

}
//——————-连接数据库

package USEUTIL;import java.sql.Connection;import java.sql.DriverManager;public  class BaseConnection {    public static Connection getConnection() {    Connection conn=null;    try {        Class.forName("com.mysql.jdbc.Driver");        conn=DriverManager.getConnection("jdbc:mysql://127.0.0.1/student_table","root","1211");    }catch (Exception e) {        e.printStackTrace();    }    return conn；}public static void main(String[] args) {    Connection conn=BaseConnection.getConnection();    System.out.println(conn);}

}
//——————–泛型DAO+JDBC增删改
package USEDAO;

import java.sql.Connection;import java.util.ArrayList;import java.sql.PreparedStatement;import java.sql.ResultSet;import USEUTIL.BaseConnection;public class StudentDao<Student> {public ArrayList<Student> getList(){    ArrayList<Student> ar=new ArrayList<Student>();    Connection conn=BaseConnection.getConnection();    PreparedStatement ps=null;    ResultSet rs=null;    try {        String sql="select * from every_stu,stu_kind where every_stu.id=stu_kind.id";        ps=conn.prepareStatement(sql);        rs=ps.executeQuery();        while(rs.next()) {            USEBEAN.Student st=new USEBEAN.Student();            st.setId(rs.getInt("id"));            st.setName(rs.getString("name"));            st.setAge(rs.getInt("age"));            st.setGrade(rs.getInt("grade"));            ar.add((Student) st);        }    } catch (Exception e) {        e.printStackTrace();    }finally {        try {            if(rs!=null) {                rs.close();            }            if(ps!=null) {                ps.close();            }            if(conn!=null) {                conn.close();            }        }catch(Exception ee) {            ee.printStackTrace();        }        }return ar;}public void insert(Student st) {    Connection conn=BaseConnection.getConnection();    PreparedStatement ps=null;    String sql="insert into every_stu(name,age) "+"values(?,?)";    try {        ps=conn.prepareStatement(sql);        ps.setString(1,((USEBEAN.Student) st).getName());        ps.setInt(2,((USEBEAN.Student) st).getAge());        int a=ps.executeUpdate();        if(a>0) {            System.out.println("添加成功");        }else {            System.out.println("添加失败");        }    } catch (Exception e) {        e.printStackTrace();    }finally {        try {            if(ps!=null) {                ps.close();            }            if(conn!=null) {                conn.close();            }        }catch(Exception ee) {            ee.printStackTrace();        }        }    }public void update(Student st) {    Connection conn=BaseConnection.getConnection();    PreparedStatement ps=null;    String sql="update every_stu set name=?,age=?"+" where id=?";    try {        ps=conn.prepareStatement(sql);        ps.setString(1,((USEBEAN.Student) st).getName());        ps.setInt(2,((USEBEAN.Student) st).getAge());        ps.setInt(3,((USEBEAN.Student) st).getId());        int a=ps.executeUpdate();        if(a>0) {            System.out.println("更新成功");        }else {            System.out.println("更新失败");        }    } catch (Exception e) {        e.printStackTrace();    }finally {        try {            if(ps!=null) {                ps.close();            }            if(conn!=null) {                conn.close();            }        }catch(Exception ee) {            ee.printStackTrace();        }        }}public void delete(int id) {    Connection conn=BaseConnection.getConnection();    PreparedStatement ps=null;    String sql="delete from every_stu where id=?";    try {        ps=conn.prepareStatement(sql);        ps.setInt(1,id);        int a=ps.executeUpdate();        if(a>0) {            System.out.println("删除成功");        }else {            System.out.println("删除失败");        }    } catch (Exception e) {        e.printStackTrace();    }finally {        try {            if(ps!=null) {                ps.close();            }            if(conn!=null) {                conn.close();            }        }catch(Exception ee) {            ee.printStackTrace();        }        }}

}
//——————控制台实现信息的增删改

    package USEMAIN;import java.util.ArrayList;import java.util.Scanner;import USEBEAN.Student;import USEDAO.StudentDao;public class TestMain {    public static void main(String[] args) {    Scanner sc=new Scanner(System.in);    StudentDao std=new StudentDao();    while(true) {        System.out.println("1、查看学生信息    2、添加学生信息    3、删除学生信息    4、修改学生信息    5、退出" );        int a=sc.nextInt();        if(a==1) {            ArrayList<Student> ar=std.getList();            System.out.println("ID  NAME    AGE GRADE");            for(Student st:ar) {                System.out.println(st.getId()+"\t"+st.getName()+"\t"+st.getAge()+"\t"+st.getGrade());            }        }else if(a==2) {            System.out.println("请输入name age");            Student st=new Student();            st.setName(sc.next());            st.setAge(sc.nextInt());            std.insert(st);        }else if(a==3) {            System.out.println("请输入ID");            std.delete(sc.nextInt());        }else if(a==4) {            System.out.println("请输入name age ID");            Student st=new Student();            st.setName(sc.next());            st.setAge(sc.nextInt());            st.setId(sc.nextInt());            std.update(st);        }else if(a==5) {            return ;        }    }}}