判断字符串编码

猜测法：猜测一种字符串编码，然后使用该编码对字符串进行编码，还原。如果猜测错误，字符串会被破坏，还原城乱码。

/**
	 * 判断字符串编码
	 * 
	 * @param str
	 * @return
	 */
	public static String getEncoding (String str)
	{

		String encode = "GB2312";
		try
		{
			if (str.equals (new String (str.getBytes (encode), encode)))
			{
				String s = encode;
				return s;
			}
		}
		catch (Exception exception)
		{
		}
		encode = "ISO-8859-1";
		try
		{
			if (str.equals (new String (str.getBytes (encode), encode)))
			{
				String s1 = encode;
				return s1;
			}
		}
		catch (Exception exception1)
		{
		}
		encode = "UTF-8";
		try
		{
			if (str.equals (new String (str.getBytes (encode), encode)))
			{
				String s2 = encode;
				return s2;
			}
		}
		catch (Exception exception2)
		{
		}
		encode = "GBK";
		try
		{
			if (str.equals (new String (str.getBytes (encode), encode)))
			{
				String s3 = encode;
				return s3;
			}
		}
		catch (Exception exception3)
		{
		}
		return "";
	}