JDBC工具类的封装

工程截图：

JDBCUtils.java中的代码：

package com.test.utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;

public class JDBCUtils {
    private static final String DRIVERCLASS;
    private static final String URL;
    private static final String USERNAME;
    private static final String PASSWORD;

    /**
     * 初始化配置信息
     */
    static {
        ResourceBundle rb = ResourceBundle.getBundle("db");     //只能加载src下的文件
        DRIVERCLASS = rb.getString("driverClass");
        URL = rb.getString("url");
        USERNAME = rb.getString("username");
        PASSWORD = rb.getString("password");
    }

    /**
     * 加载驱动,获得连接
     */
    public static Connection getConnection() {
        Connection conn = null;
        try {
            Class.forName(DRIVERCLASS);
            conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return conn;
    }

    /**
     * 关闭结果集
     */
    public static void close(ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            rs = null;
        }
    }

    /**
     * 关闭statement
     */
    public static void close(PreparedStatement pstmt) {
        if (pstmt != null) {
            try {
                pstmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            pstmt = null;
        }
    }

    /**
     * 关闭连接
     */
    public static void close(Connection conn) {
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            conn = null;
        }
    }
}

properties中的代码：

driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/test
username=root
password=123456