如何让一个字符串反转（三种方法）

package com;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.Stack;public class StringReverse {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubBufferedReader br = new BufferedReader(new InputStreamReader(System.in));String string = " ";StringBuffer retBuffer = new StringBuffer("");/* * 方法一 */try {string = br.readLine();} catch (IOException ex) {System.out.println(ex);}char[] retChar = new char[string.length()];for (int i = string.length() - 1, j = 0; i >= 0; i--, j++) {retChar[j] = string.charAt(i);}System.out.println(String.valueOf(retChar));/* * 方法二 */StringBuffer sb = new StringBuffer(string);System.out.println(sb.reverse().toString());System.out.println(reverse(string));}/* * 堆栈的方法反转 */public static String reverse(String in) {String input = in;String output;//执行反转Stack<Character> theStack = new Stack<Character>();for (int j = 0; j < input.length(); j++) {char ch = input.charAt(j);theStack.push(ch);}output = "";while (!theStack.isEmpty()) {char ch = theStack.pop();output = output + ch;}return output;}}