判断是否为回文数

private void huiwennum() {        String ss =ethuiwen.getText().toString();        char[] ch = ss.toCharArray();        boolean is = true;        int j = ch.length;        for (int i = 0; i < j / 2; i++) {                        if (ch[i] != ch[j - i - 1]) {                               is = false;                           }                    }                if (is == true) {                    Toast.makeText(MainActivity.this,"这是一个回文数",Toast.LENGTH_LONG).show();                } else {                    Toast.makeText(MainActivity.this,"这不是一个回文数",Toast.LENGTH_LONG).show();                }    }