控制层Action接受从模型层DAO传来的数据，显现在视图层上。

 

 

package Action;import java.sql.Connection;import java.sql.SQLException;import java.sql.Statement;import DAO.StuDAO;import Model.Student;import Util.DBUtil;public class StuAction {        public static void main(String args[]) throws Exception {            Connection conn = DBUtil.getConnection();            Statement stmt = conn.createStatement();//            ResultSet rs = stmt.executeQuery("select * from stuInfoTable");    //            while(rs.next()) {
                    System.out.println(rs.getInt(1)+" "+ rs.getString(2)+" "+rs.getString(3));            }            //不是直接 Student stu = null，这样试空指针            Student stu = new Student();            stu.setStuID(5);            stu.setName("王五");            stu.setSex("女");            StuDAO sd = new StuDAO();            //sd.addStu(stu);            //            stu.setName("马六");//            stu.setSex("男");//            sd.updateStu(stu);                        sd.delStu(stu.getStuID());                }            //直接调用StuDAO的方法来更新 增加 删除    public void add(Student stu) throws Exception {        StuDAO sd = new StuDAO();        sd.addStu(stu);    }    //通过控制层来 链接视图层}

 

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 Model.Student;import Util.DBUtil;public class StuDAO {    Connection conn = DBUtil.getConnection();    //一个一个传参数很麻烦 直接传一个对象    //如果stuID设置了自动递增  就不需要插入了    public void  addStu(Student stu) throws Exception {        String sql ="" + "insert into stuInfoTable" + "(" +                " stuID,name,sex"+")" + "values(" + "?,?,?)";        //这样的语句可以预加载在服务器里 execute后才会执行        PreparedStatement ps = conn.prepareStatement(sql);        ps.setInt(1, stu.getStuID());        ps.setString(2, stu.getName());        ps.setString(3, stu.getSex());        ps.execute();    }    //和增加的逻辑一直  所以直接复制上述代码 然后修改sql语句    //可以直接传过来stuID，但是这样需要根据ID去找Student    public void updateStu(Student stu) throws Exception {        //不加where语句的话 所有的都会更新                //注意下面的语句   一定要有空格        String sql ="" + "update stuInfoTable " + "set " +                "name=?,sex=? " + "where "+ "stuID=?";        //这样的语句可以预加载在服务器里 execute后才会执行        PreparedStatement ps = conn.prepareStatement(sql);        //打印出来sql语句 发现 中间少了 空格 然后修改上面的sql语句        System.out.println(sql);        //注意下面的 序号 要和update的序号一致        ps.setString(1, stu.getName());        ps.setString(2, stu.getSex());        ps.setInt(3, stu.getStuID());        ps.execute();    }    public void delStu(int stuID) throws Exception {                String sql ="" + "delete stuInfoTable " +"where "+ "stuID=?";        PreparedStatement ps = conn.prepareStatement(sql);        ps.setInt(1, stuID);        ps.execute();    }    //查询学生集合    public List
     
       queryStu() throws Exception {        Statement stmt = conn.createStatement();        ResultSet rs = stmt.executeQuery("select * from stuInfoTable");                List
      
        stuList = new ArrayList
       
        ();        Student stu = null;        while(rs.next()) {            stu = new Student();            stu.setStuID(rs.getInt(1));            stu.setName(rs.getString(2));            stu.setSex(rs.getString(3));            stuList.add(stu);        }        return stuList;    }    //查询一个学生    //应该需要和上面重载的 但是为了做实验 先写完所有方法 再去实现    public Student queryOneStu() {        return null;    }}
       
      
     

package Model;public class Student {    int stuID;    String name;    String sex;    public int getStuID() {        return stuID;    }    public void setStuID(int stuID) {        this.stuID = stuID;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    }

package Util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import DAO.StuDAO;import Model.Student;public class DBUtil {    private static Connection conn;    static {        String url = "jdbc:sqlserver://localhost:1433;databasename=stuDB";        try {            // 1.注册驱动\            // Class.forName("com.mysql.jdbc.Driver");            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");            // 2.获得数据链接            conn = DriverManager.getConnection(url, "sa", "123456");        } catch (ClassNotFoundException | SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    public static Connection getConnection() {        return conn;    }}