JDBC

package com.hei.jdbcdemo;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Test {
	public static void main(String[] args) {
		Connection conn = null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		try {
			conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/student","root","");
		} catch (SQLException e) {
			e.printStackTrace();
		}
		String sql="select id,name from student";
		try {
			Statement stmt = conn.createStatement();
			ResultSet rs=stmt.executeQuery(sql);
			while(rs.next()){
				int id = rs.getInt(1);
				String name = rs.getString(2);
				System.out.println("id:"+id+",name:"+name);
			}
			
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			if(conn!=null){
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	
	}
}

Properties prop = new Properties();
Reader in = new FileReader("src\\config.propertions");
			prop.load(in);
driver=prop.getProperty("driver");
url=prop.getProperty("url");
username=prop.getProperty("username");
password=prop.getProperty("password");

public class Test2 {
	public static void main(String[] args) {
		//createTable();
		//insert();
		//updata();
		//delete();
		query();
	}
	static void createTable(){
		Connection conn = DBUtil.open();
		String sql = "create table UserTbl(id int primary key auto_increment,name varchar(20))";
		try {
			Statement stmt = conn.createStatement();
			stmt.execute(sql);
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
		
	}
	static void insert(){
		Connection conn = DBUtil.open();
		String sql = "insert UserTbl Values(NULL,‘Tom‘)";
		try {
			Statement stat = conn.createStatement();
			stat.executeUpdate(sql);
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
	}
	static void updata(){
		Connection conn = DBUtil.open();
		String sql = "update UserTbl set name=‘BigTom‘ where id>3";
		try {
			Statement stat = conn.createStatement();
			stat.executeUpdate(sql);
		} catch (Exception e) {
			
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
	}
	static void delete(){
		Connection conn = DBUtil.open();
		String sql = "delete from UserTbl where id=1";
		try {
			Statement stat = conn.createStatement();
			stat.executeUpdate(sql);
		} catch (Exception e) {
			
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
	}
	static List<User> query(){
		Connection conn = DBUtil.open();
		String sql = "select id,name from UserTbl";
		List<User> list= new ArrayList<User>(); 
		try{
			Statement stmt = conn.createStatement();
			ResultSet rs = stmt.executeQuery(sql);
			while(rs.next()){
				int id = rs.getInt(1);
				String name = rs.getString(2);
				User u = new User();
				u.setId(id);
				u.setName(name);
				list.add(u);
				//System.out.println("id"+id+"   name"+name);
			}
			System.out.println(list);
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
		return list;
	}
}

	static void insert(String name,int id){
		String sql = "insert into UserTbl(id,name)values(?,?)";
		Connection conn = DBUtil.open();
		try {
			PreparedStatement pstmt = conn.prepareStatement(sql);
			pstmt.setInt(1,id);
			pstmt.setString(2, name);
			pstmt.executeUpdate();
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			DBUtil.close(conn);
		}
	}

public static List<Student> select(){
		Connection conn=DBUtil.open();
		List<Student> list = new ArrayList<Student>();
		String sql ="select * from Stud";
		try {
			Statement stat =conn.createStatement();
			ResultSet rs = stat.executeQuery(sql);//结果集
			while(rs.next()){
				int id = rs.getInt(1);
				String name = rs.getString(2);
				int age = rs.getInt(3);
				String sex = rs.getString(4);
				Date date = rs.getDate(5);
				Student student=new Student();
				student.setAge(age);
				student.setDate(date);
				student.setId(id);
				student.setName(name);
				student.setSex(sex);
				list.add(student);
			}
			for (Student student : list) {
				System.out.println(student);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			try {
				conn.close();
			} catch (SQLException e) {
				
				e.printStackTrace();
			}		
		}	return list;
	}