jar 读包外配置文件

package com.ext.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.log4j.Logger;

public class Config {
private static Properties properties;
private static Logger logger = Logger.getLogger(Config.class);
static {
properties = new Properties();

String url = ClassLoader.getSystemResource(".").toString();
StringBuffer sb=new StringBuffer();
sb.append(url.substring(url.indexOf("/")+1, url.indexOf("classes"))).append("config.properties");
File file = new File(sb.toString());
try {
InputStream is =new FileInputStream(file);

properties.load(is); 
} catch (FileNotFoundException e) {
logger.error("配置文件config.properties找不到！"+e);
} catch (IOException e) {
logger.error("读取配置文件config.properties错误！"+e);
}
}
public static String getObject(String prepKey) {
return properties.getProperty(prepKey);
}

public static void main(String[] agrs) {
System.out.println(Config.getObject("url"));
}

}











/*jadclipse*/// Decompiled by Jad v1.5.8f. Copyright 2001 Pavel Kouznetsov.

package dao;

import java.io.PrintStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Properties;

public class DB
{

    public DB()
    {
    }

    public static Connection getConnectionByConfig()
    {
        Connection conn = null;
        try
        {
            String driver = config.getProperty("driver");
            String url = config.getProperty("url");
            String username = config.getProperty("username");
            String password = config.getProperty("password");
            Class.forName(driver);
            conn = DriverManager.getConnection(url, username, password);
            System.out.println("\u8FDE\u63A5\u5230\u6570\u636E\u5E93\u6210\u529F");
        }
        catch(Exception e)
        {
            e.printStackTrace();
            System.out.println("\u8FDE\u63A5\u5230\u6570\u636E\u5E93\u5931\u8D25");
        }
        return conn;
    }

    private static Properties config;

    static
    {
        config = new Properties();
        try
        {
            java.io.InputStream in = dao/DB.getClassLoader().getResourceAsStream("config.properties");
            config.load(in);
            System.out.println("\u8BFB\u53D6\u6587\u4EF6\u6210\u529F");
        }
        catch(Throwable t)
        {
            System.out.println("\u8BFB\u53D6\u6587\u4EF6\u5931\u8D25");
            t.printStackTrace();
            throw new ExceptionInInitializerError();
        }
    }
}


/*
DECOMPILATION REPORT

Decompiled from: D:\workspace\extjsdemo\WebRoot\WEB-INF\lib\DB.jar
Total time: 265 ms
Jad reported messages/errors:
The class file version is 50.0 (only 45.3, 46.0 and 47.0 are supported)
Exit status: 0
Caught exceptions:
*/