用類加載器加載resources目錄下的jdbc.properties文件(支持打成jar包後路徑依然支持)

package cn.itcast.util;

import java.io.FileReader;
import java.io.InputStream;
import java.net.URL;
import java.sql.*;
import java.util.Properties;

public class JDBCUtils {
    private static String url;
    private static String user;
    private static String password;
    private static String driver;

    static {
        try {
            Properties pro = new Properties();
            ClassLoader classLoader = JDBCUtils.class.getClassLoader();
            InputStream inputStream = classLoader.getResourceAsStream("jdbc.properties");
            pro.load(inputStream);
            url = pro.getProperty("url");
            user = pro.getProperty("user");
            password = pro.getProperty("password");

            driver = pro.getProperty("driver");
            Class.forName(driver);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static Connection getConnection() throws Exception {
        return DriverManager.getConnection(url, user, password);
    }

    public static void close(Statement stmt, Connection conn) {
        if (stmt != null) {
            try {
                stmt.close();
                stmt = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
                conn = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close(ResultSet rs, Statement stmt, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
                rs = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (stmt != null) {
            try {
                stmt.close();
                stmt = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
                conn = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}