java jdbc实现

JDBC连接数据库

public class TestMysql {
	public static void main(String[] args) throws Exception{
		//1、加载驱动程序
		Class.forName("com.mysql.jdbc.Driver");
		//连接MySql数据库，用户名和密码都是root   
                 /*
                  oracle:
                  Class.forName("oracle.jdbc.driver.OracleDriver");
                  String url =jdbc:oracle:thin:@127.0.0.1:1521:test
                 */
	    String url = "jdbc:mysql://localhost:3306/test" ;    
	    String username = "root" ;   
	    String password = "root" ; 


	    //2、获取数据库连接
	    Connection conn =null;
		conn = DriverManager.getConnection(url, username, password);
		//3、创建一个Statement
		//Statement smt = conn.createStatement();
		String sql ="select * from t_user";
		PreparedStatement psmt = conn.prepareStatement(sql);
		//4、执行SQL
		ResultSet rs = psmt.executeQuery();
		//5、处理结果
		while(rs.next()){
			System.out.println(rs.getInt(1)+"-"+rs.getString(2)+"-"+rs.getString(3));
		}
		//6、关闭连接
		if(rs!=null){
			rs.close();
		}
	}
}