字符串比如“ad2 lsdkf,lksdjf. sdkfj”倒序排列"sdkfj lksdjf. lsdkf,ad2" 每个单词是空格分开，标点符号当作字母，不能用String的自带的一些方法,比如indexof,trim,split等方法。

public static void myConvert(String source) {

		char[] tmpArray = source.tocharArray();

		StringBuffer out = new StringBuffer();
		StringBuffer tmp = new StringBuffer();
		for (int index = tmpArray.length - 1; index >= 0; index--) {
			if (tmpArray[index] == ' ') {
				out.append(" ");
				tmp.append(out);
				out.delete(0,out.length());
			} else {
				out.insert(0,tmpArray[index]);
			}
		}
		tmp.append(out);
		System.out.println(tmp.toString());

	}

	public static void reverseString(String source) {
		
		char[] cTemp = source.tocharArray();
		String newString = "";
		String sTemp = "";
		for (int i = cTemp.length - 1; i >= 0; i--) {
			if (cTemp[i] == ' ') {
				newString += sTemp + cTemp[i];
				sTemp = "";
			} else {
				sTemp = cTemp[i] + sTemp;
			}
		}
		newString += sTemp;
		System.out.println(newString);
	}

此题源地址：http://www.iteye.com/topic/786985