方法一:
public class StringReverse { public void swap(char[] arr, int begin, int end) { while(begin < end) { char temp = arr[begin]; arr[begin] = arr[end]; arr[end] = temp; begin++; end--; } } //I love java public String swapWords(String str) { char[] arr = str.toCharArray(); swap(arr, 0, arr.length - 1); int begin = 0; for (int i = 1; i < arr.length; i++) { if (arr[i] == ' ') { swap(arr, begin, i - 1); begin = i + 1; } } return new String(arr); } public static void main(String[] args) { String str = "I love java"; System.out.println(new StringReverse().swapWords(str)); } }