Queue的add()和offer()方法有什么区别？ - ConstXiong - 博客园

• Queue 中 add() 和 offer() 都是用来向队列添加一个元素。
• 在容量已满的情况下，add() 方法会抛出 IllegalStateException 异常，offer() 方法只会返回 false 。

JDK1.8 源码中的解释

/_*

• Inserts the specified element into this queue if it is possible to do so
  
• immediately without violating capacity restrictions, returning
  
• {@code true} upon success and throwing an {@code IllegalStateException}
  
• if no space is currently available.
  *
  
• @param e the element to add
  
• @return {@code true} (as specified by {@link Collection#add})
  
• @throws IllegalStateException if the element cannot be added at this
  
• time due to capacity restrictions
  
• @throws ClassCastException if the class of the specified element
  
• prevents it from being added to this queue
  
• @throws NullPointerException if the specified element is null and
  
• this queue does not permit null elements
  
• @throws IllegalArgumentException if some property of this element
  
• prevents it from being added to this queue / boolean add(E e); /*
  
• Inserts the specified element into this queue if it is possible to do
  
• so immediately without violating capacity restrictions.
  
• When using a capacity-restricted queue, this method is generally
  
• preferable to {@link #add}, which can fail to insert an element only
  
• by throwing an exception.
  *
  
• @param e the element to add
  
• @return {@code true} if the element was added to this queue, else
  
• {@code false}
  
• @throws ClassCastException if the class of the specified element
  
• prevents it from being added to this queue
  
• @throws NullPointerException if the specified element is null and
  
• this queue does not permit null elements
  
• @throws IllegalArgumentException if some property of this element
  
• prevents it from being added to this queue _/ boolean offer(E e);

来一道刷了进 BAT 的面试题？

https://www.cnblogs.com/ConstXiong/p/11896127.html