错误小计

1.比较器的错误

Caused by: java.lang.IllegalArgumentException: Comparison method violates its general contract!   at java.util.ComparableTimSort.mergeLo(ComparableTimSort.java:710)   at java.util.ComparableTimSort.mergeAt(ComparableTimSort.java:447)   at java.util.ComparableTimSort.mergeCollapse(ComparableTimSort.java:372)   at java.util.ComparableTimSort.sort(ComparableTimSort.java:178)   at java.util.ComparableTimSort.sort(ComparableTimSort.java:142)   at java.util.Arrays.sort(Arrays.java:1957)   at java.util.Collections.sort(Collections.java:1864)

原因分析：
1.比较方法中没有比较==0的情况，如下：

  return lhs < rhs ? -1 : 1;

正确的比较方法：

public static int compare(long lhs, long rhs) {    return lhs < rhs ? -1 : (lhs == rhs ? 0 : 1);}   

2.调用系统的str1.compareTo(str2)方法时，前后的字符串为空了