package jdbc;

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

public class TestJDBC {
 public static void main(String[] args) {

  try {
   Class.forName("com.mysql.jdbc.Driver");

   // 建立与数据库的Connection连接
   // 数据库所处于的ip:127.0.0.1 (本机)
   // 数据库的端口号： 3306 （mysql专用端口号）
   // 数据库名称 studinfo
   // 编码方式 UTF-8
   // 账号 root
   // 密码 admin

   Connection c = DriverManager
     .getConnection(
       "jdbc:mysql://127.0.0.1:3306/studinfo?characterEncoding=UTF-8",
       "root", "admin");

   System.out.println("连接成功，获取连接对象： " + c);

  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (SQLException e) ｛
   e.printStackTrace();
  }

 }
}

package jdbc;

import java.util.List;

import charactor.student;

public interface DAO{
 //增加
 public void add(student stud);
 //修改
 public void update(student stud);
 //删除
 public void delete(int id);
 //获取
 public Hero get(int id);
 //查询
 public List<student> list();
 //分页查询
 public List<student> list(int start, int count);
}

package util;

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

public class DBUtil {
 static String ip = "127.0.0.1";
 static int port = 3306;
 static String database = "student";
 static String encoding = "UTF-8";
 static String loginName = "root";
 static String password = "admin";
 static{
  try {
   Class.forName("com.mysql.jdbc.Driver");
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }
 }

 public static Connection getConnection() throws SQLException {
  String url = String.format("jdbc:mysql://%s:%d/%s?characterEncoding=%s", ip, port, database, encoding);
  return DriverManager.getConnection(url, loginName, password);
 }
}

// update 实现代码片段

public update(Student stu) { 
  boolean result = false; 
  if (stu == null) { 
   return result; 
  } 
  try { 
   // check 
   if (queryBySno(stu.getSno()) == 0) { 
    return result; 
   } 
   // 实现update
   String sql = "update student set id=?,name=?,class=?,sex=?"; 
   String[] param = { stu.getId(), stu.getName(), stu.getClass(), stu.getSex() }; 
   int rowCount = db.executeUpdate(sql, param); 
   if (rowCount == 1) { 
    result = true; 
   } 
  } catch (SQLException se) { 
   se.printStackTrace(); 
  } finally { 
   destroy(); 
  } 
  return result; 
 } 

String sql = "delete from student where id＝？”; 
String[] param = { stu.getId()}; 

String sql = "insert into student(id，name，class，sex) values(?,?,?,?)"; 
String[] param = { stu.getId(), stu.getName(), stu.getClass(), stu.getSex()};   

private int queryById(String id) throws SQLException { 
 int result = 0; 
 if ("".equals(id) || id == null) { 
  return result; 
 } 
 String checkSql = "select * from student where id=?"; 
 String[] checkParam = { id }; 
 rs = db.executeQuery(checkSql, checkParam); 
 if (rs.next()) { 
  result = 1; 
 } 
 return result; 
 } 

}