- jdbc.properties
- url=jdbc:MySQL:///db3
- user=root
- password=root
- driver=com.MySQL.jdbc.Driver
JDBCUtils.java
- import java.io.FileReader;
- import java.io.IOException;
- import java.NET.URL;
- import java.sql.*;
- import java.util.Properties;
- /**
- * JDBC 工具类
- */
- public class JDBCUtils {
- private static String url;
- private static String user;
- private static String password;
- private static String driver;
- /**
- * 文件的读取, 只需要读取一次即可拿到这些值. 使用静态代码块
- */
- static{
- // 读取资源文件, 获取值.
- try {
- //1. 创建 Properties 集合类.
- Properties pro = new Properties();
- // 获取 src 路径下的文件的方式 --->ClassLoader 类加载器
- ClassLoader classLoader = JDBCUtils.class.getClassLoader();
- URL res = classLoader.getResource("jdbc.properties");
- String path = res.getPath();
- // System.out.println(path);///D:/IdeaProjects/itcast/out/production/day04_jdbc/jdbc.properties
- //2. 加载文件
- // pro.load(new FileReader("D:\\IdeaProjects\\itcast\\day04_jdbc\\src\\jdbc.properties"));
- pro.load(new FileReader(path));
- //3. 获取数据, 赋值
- url = pro.getProperty("url");
- user = pro.getProperty("user");
- password = pro.getProperty("password");
- driver = pro.getProperty("driver");
- //4. 注册驱动
- Class.forName(driver);
- } catch (IOException e) {
- e.printStackTrace();
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- }
- }
- /**
- * 获取连接
- * @return 连接对象
- */
- public static Connection getConnection() throws SQLException {
- return DriverManager.getConnection(url, user, password);
- }
- /**
- * 释放资源
- * @param stmt
- * @param conn
- */
- public static void close(Statement stmt,Connection conn){
- if( stmt != null){
- try {
- stmt.close();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- if( conn != null){
- try {
- conn.close();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- }
- /**
- * 释放资源
- * @param stmt
- * @param conn
- */
- public static void close(ResultSet rs,Statement stmt, Connection conn){
- if( rs != null){
- try {
- rs.close();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- if( stmt != null){
- try {
- stmt.close();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- if( conn != null){
- try {
- conn.close();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- }
- }
来源: http://www.bubuko.com/infodetail-3497633.html