StringBuilder中reverse的疑问

public AbstractStringBuilder reverse() { boolean hasSurrogate = false; int n = count - 1; for (int j = (n-1) >> 1; j >= 0; --j) { char temp = value[j]; char temp2 = value[n - j]; if (!hasSurrogate) { hasSurrogate = (temp >= Character.MIN_SURROGATE && temp <= Character.MAX_SURROGATE) || (temp2 >= Character.MIN_SURROGATE && temp2 <= Character.MAX_SURROGATE); } value[j] = temp2; value[n - j] = temp; } if (hasSurrogate) { // Reverse back all valid surrogate pairs for (int i = 0; i < count - 1; i++) { char c2 = value[i]; if (Character.isLowSurrogate(c2)) { char c1 = value[i + 1]; if (Character.isHighSurrogate(c1)) { value[i++] = c1; value[i] = c2; } } } } return this; }

上面是reverse的源码，其中hasSurrogate表示unicode编码占用一个还是两个字符。

现在想实现：构造一个StringBuilder对象，调用其reverse方法，进行调试，使其满足hasSurrogate 为true

的情况。

尝试使用中文字符，但是无效，比如：os我china，调试时hasSurrogate仍然为false。

求大家指点。