一个日期转换函数

/*
tranlsate(GHIJABDE,12/31/1999, ABCDEFGHIJ ) -> 19991231
translate(AB-GHIJ, 12/31/1999, ABCDEFGHIJ) ->12-1999
translate(GHIJ-AB-DE, 12/31/1999, ABCDEFGHIJ) ->1999-12-31
For each character of the input, if that character is found in InTable,it is replaced with the character from OutTable
*/

public static String translate(String input, String outTable, String inTable) {
		if (null == input)
			return input;
		String output = input;
		outTable = left(outTable, inTable.length());
		for (int i = 0; i < inTable.length(); i++) {
			output = output.replace(inTable.charAt(i), outTable.charAt(i));
		}
		return output;
	}

	public static String left(String input, int length) {
		return left(input, length, " ");
	}

	public static String left(String input, int length, String pad) {
		StringBuffer output = new StringBuffer(input);
		for (int i = input.length(); i < length; i += pad.length()) {
			output.append(pad);
		}
		return output.toString().substring(0, length);
	}