java - Best Practice in handling comparator

Question

How to handle null objects, which comes in compareTo method. This always causes nullpointer exception. What a is best way to solve this issue.

Answer 1

public int compareTo(Object to) {
  if (to == null) return Integer.MIN_VALUE;
  // Now knowing it's not null, continue as before
}

Answer 2

您可以在调用“compareTo”方法之前检查对象。

像这样：

if(obj != null){

  //TODO  

}

Answer 3

来自Comparable的精美文档：

请注意，null 不是任何类的实例，即使 e.equals(null) 返回 false，e.compareTo(null) 也应该抛出 NullPointerException。

如果您不想处理 NullPointerExceptions，请不要将 null 放入已排序的集合中。