java java中subString、split、stringTokenizer三种截取字符串方法的性能比较

都知道在大数据量情况下，使用String的split截取字符串效率很低，这种时候可以用substring，stringTokenizer

代替，效率会有一定的提高，而stringTokenizer中实际是通过调用substring实现的。

stringTokenizer中nextToken()代码如下:

public String nextToken() {
/*
* If next position already computed in hasMoreElements() and
* delimiters have changed between the computation and this invocation,
* then use the computed value.
*/

currentPosition = (newPosition >= 0 && !delimsChanged) ?
newPosition : skipDelimiters(currentPosition);

/* Reset these anyway */
delimsChanged = false;
newPosition = -1;

if (currentPosition >= maxPosition)
throw new NoSuchElementException();
int start = currentPosition;
currentPosition = scanToken(currentPosition);
return str.substring(start, currentPosition);
}

想要查看测试结果可以看这篇博客
点击打开链接 忽略其中的stringTokenizer部分。stringTokenizer应该并不会比substring高效。而且StringTokenizer是出于兼容性的原因而被保留的遗留类(在新代码中并不鼓励使用它)