【Java实用技术】字符串的拆分怎么最快？

importorg.apache.commons.lang3.StringUtils;
/*** Java实用技术课程 By Pandas.* 公众号：Java实用技术手册* JDK版本：jdk1.8.0_66** @author Pandas* @date 2021/10/31*/publicclassStringSplitQuick {
publicstaticvoidmain(String[] args) {
StringBuildersb=newStringBuilder();
intmax=100_0000;
for (inti=0; i<max; i++) {
sb.append("a.");
        }
// 构造一个100W个"a."拼接成的字符串:"a.a.a.a.a.......a."Stringstr=sb.toString();
longstart1=System.currentTimeMillis();
String[] cs1=str.split("\\.");
longcost1=System.currentTimeMillis() -start1;
longstart2=System.currentTimeMillis();
String[] cs2=StringUtils.split(str, '.');
longcost2=System.currentTimeMillis() -start2;
longstart11=System.currentTimeMillis();
String[] cs11=str.split("a");
longcost11=System.currentTimeMillis() -start11;
longstart22=System.currentTimeMillis();
String[] cs22=StringUtils.split(str, 'a');
longcost22=System.currentTimeMillis() -start22;
System.out.println("原生拆分.耗时："+cost1+"ms");
System.out.println("StringUtils拆分.耗时："+cost2+"ms");
System.out.println("原生拆分a耗时："+cost11+"ms");
System.out.println("StringUtils拆分a耗时："+cost22+"ms");
    }
}

public<T>T[] toArray(T[] a) {
if (a.length<size)
// Make a new array of a's runtime type, but my contents:return (T[]) Arrays.copyOf(elementData, size, a.getClass());
System.arraycopy(elementData, 0, a, 0, size);
if (a.length>size)
a[size] =null;
returna;
}