java 字符串反转

String 为i love you反转成为you love i

    public void test(){        String str = "i love you";        StringBuilder sb = new StringBuilder(str);        str = sb.reverse().toString();        char[] ch = str.toCharArray();        int begin = 0,end=0;        for(;end<str.length();end++){            if(ch[end]==' '){                reverse(ch,begin,end-1);                begin = end+1;            }        }        reverse(ch,begin,end-1);        System.out.println(ch);    }    public void reverse(char[] str,int begin,int end){        while(begin<end){            char tmp = str[begin];            str[begin] = str[end];            str[end] = tmp;            begin++;            end--;        }    }