Java 其中翻转字符串的实现方法

import java.util.Stack;

public class StringReverse {

public static String reverse1(String s) {

   int length = s.length();

   if (length <= 1)

    return s;

   String left = s.substring(0, length / 2);

   String right = s.substring(length / 2, length);

   return reverse1(right) + reverse1(left);

 }

 public static String reverse2(String s) {

   int length = s.length();

   String reverse = "";

   for (int i = 0; i < length; i++)

    reverse = s.charAt(i) + reverse;

   return reverse;

  }

  public static String reverse3(String s) {

   char[] array = s.toCharArray();

   String reverse = "";

   for (int i = array.length - 1; i >= 0; i--)

    reverse += array[i];

   return reverse;

  }

  public static String reverse4(String s) {

   return new StringBuffer(s).reverse().toString();

  }

  public static String reverse5(String orig) {

   char[] s = orig.toCharArray();

   int n = s.length - 1;

   int halfLength = n / 2;

   for (int i = 0; i <= halfLength; i++) {

    char temp = s[i];

    s[i] = s[n - i];

    s[n - i] = temp;

   }

   return new String(s);

  }

  public static String reverse6(String s) {

   char[] str = s.toCharArray();

   int begin = 0;

   int end = s.length() - 1;

   while (begin < end) {

    str[begin] = (char) (str[begin] ^ str[end]);

    str[end] = (char) (str[begin] ^ str[end]);

    str[begin] = (char) (str[end] ^ str[begin]);

    begin++;

    end--;

   }

   return new String(str);

  }

  public static String reverse7(String s) {

   char[] str = s.toCharArray();

   Stack<Character> stack = new Stack<Character>();

   for (int i = 0; i < str.length; i++)

    stack.push(str[i]);

   String reversed = "";

   for (int i = 0; i < str.length; i++)

    reversed += stack.pop();

   return reversed;

  }

 }