实现比较器,重写compare方法时老毕是这样写的
class StrLenComparator implements Comparator<String>
{
public int compare(String str1,String str2)
{
int num = new Integer(str1.length()).compareTo(new Integer(str2.length()));
//我会写成这样 int num = str1.length()-str2.length();
if(num==0)
return str1.compareTo(str2);
return num;
}
}