JDBC数据库操作通用类

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;


public class JDBConnection {
    public Connection conn = null; // 声明Connection对象的实例
    public Statement stmt = null; // 声明Statement对象的实例
    public ResultSet rs = null; // 声明ResultSet对象的实例
    
    private static String dbClassName = "com.microsoft.jdbc.sqlserver.SQLServerDriver";//定义保存数据库驱动的变量
    private static String dbUrl = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=DB_ATM";
    private static String dbUser = "sa";
    private static String dbPwd = "sa";

    public JDBConnection(String propertyFileName) {// 带属性文件名的构造方法
        Properties prop = new Properties();// 属性集合对象
        InputStream is = null;
        try {
            is = JDBConnection.class.getClassLoader().getResourceAsStream(
                    propertyFileName);// 属性文件输入流
            // is = new FileInputStream("src/" + propertyFileName);
            prop.load(is);// 将属性文件流装载到Properties对象中
            is.close();// 关闭流
            dbClassName = prop.getProperty("dbClassName");
            dbUrl = prop.getProperty("dbUrl");