反转字符串，如"Hello World",输出为 "olleH dlroW",不使用库函数

	public static void main(String[] args) {
		/**
		 * 输出olleH dlroW,不使用库函数
		 */
		String str = "Hello World";
		int strLength = str.length();//字符长度
		int wordLength = 0;//每个单词的长度
		int stStrIndex = 0;//结果字符集下标
		
		char[] strs = str.toCharArray();
		char[] rtStr = new char[strLength];
		
		for(int i = 0;i < strLength;i++) {
			if(strs[i] == ' ') {
				for(int j=0;j < wordLength;j++) {
					rtStr[stStrIndex] = strs[i-j-1];
					stStrIndex++;
				}
				rtStr[i] = ' ';
				stStrIndex++;
				wordLength = 0;
			}else if(i == strLength-1) {
				for(int j=0;j < wordLength+1;j++) {
					rtStr[stStrIndex] = strs[i-j];
					stStrIndex++;
				}
			}else {
				wordLength++;
			}
		}
		
		StringBuffer sb = new StringBuffer();
		for(char s:rtStr) {
			sb.append(Character.toString(s));
		}
		
		System.out.println(sb);
	}