Java JDBC典型运用

package nh.spring.tools.db;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
public class TestDBConnection {
    /**
     * 典型jdbc连接
     * 1，与数据库建立连接
       2，发送SQL语句
       3，处理返回结果
     */
    static Connection con = null;
    static Statement stmt = null;
    static ResultSet rs = null;
     
    public static void main(String[] args) {    
        try {
            // 1、加载MYSQL驱动，这里MySQL的JDBC驱动类是com.mysql.jdbc.Driver，要求类路径中包含相应的Driver类
            Class.forName("com.mysql.jdbc.Driver").newInstance(); 
             
            // 2、连接到MYSQL，通过DriverManger来创建Connection对象，获取数据库连接
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/vShop", "root", "niuheng"); 
             
            // 3、创建Statement用以执行SQL语句，或者可以使用PreparedStatement
            Statement stmt = con.createStatement();
             
            // 4、执行SQL，获取结果
            ResultSet rs = stmt.executeQuery("select * from user");
            // 或者执行增删改操作，如：stmt.executeUpdate("delete * from blog");
             
            // 5、遍历并解析结果
            while (rs.next()) {
                long id = rs.getLong("id"); // 获取id列
                String username = rs.getString("username"); // 获取username列
                System.out.println("id:"+id+" Name:" +username);
            }
        } catch (Exception e) {
             
            // 如果有异常，进行异常处理
            System.out.print("MYSQL ERROR:" + e.getMessage());
             
        } finally {
            // 6、清理数据库连接相关的所有资源
            try {
                if (rs != null) {
                    rs.close();
                }
                 
                if (stmt != null) {
                    stmt.close();
                }
                 
                if (con != null) {
                    con.close();
                }
            } catch (SQLException ignored) {
                 
            }
        }
    }
 
}