关于String字符串反转

        String str = "1234567";        int length = str.length();        int beginIndex = length-1;        char[] sourceCharArray = str.toCharArray();        char[] discCharArray = new char[length];        int j=0;        for(int i=beginIndex; i>=0; i--){            discCharArray[j] = sourceCharArray[i];            j++;        }        String newStr = String.valueOf(discCharArray);