自动获取文件路径

private static String getRealClassPath()
	{
		URL url = new Constants().getClass().getResource("Constants.class");
        String path = url.toString();
        String propFilePath = "";
		int indexjar = path.indexOf("jar!");
		if (indexjar != -1) {
			int jarPath = path.lastIndexOf("/", indexjar);
			propFilePath = path.substring("jar:file:/".length(),
					jarPath + 1);
		} else {
			int webIndex = path.indexOf("WEB-INF");
			propFilePath = path.substring("file:/".length(), webIndex);
			propFilePath = propFilePath + "WEB-INF/classes/";
		}
		if (propFilePath.charAt(1) != ':') {
			propFilePath = "/" + propFilePath;
		}
		int end = propFilePath.indexOf("ROOT");
		propFilePath = propFilePath.substring(0, end+"ROOT".length()+1);
		return propFilePath;
	}

Constants.class 文件的路径地址