--- jsr166/src/main/java/util/Queue.java 2004/11/21 01:40:39 1.23 +++ jsr166/src/main/java/util/Queue.java 2004/12/26 20:13:57 1.24 @@ -8,32 +8,38 @@ package java.util; /** * A collection designed for holding elements prior to processing. - * Besides basic {@link java.util.Collection Collection} operations, queues provide - * additional insertion, extraction, and inspection operations. The names - * of the operations vary with their policies: + * Besides basic {@link java.util.Collection Collection} operations, + * queues provide additional insertion, extraction, and inspection + * operations. Each of these methods exists in two forms: one throws + * an exception if the operation fails, the other returns a special + * value (either null or false, depending on the + * operation). The latter form of the insert operation is designed + * specifically for use with capacity-restricted Queue + * implementations; in most implementations, insert operations cannot + * fail. * - * + *
* - * - * - * + * + * + * * * - * - * - * + * + * + * * * - * - * - * + * + * + * * * - * - * - * + * + * + * * - *
OperationAttemptThrowThrows exceptionReturns special value
insertoffer(x)add(x)Insert{@link #add add(e)}{@link #offer offer(e)}
extractpoll()remove()Remove{@link #remove remove()}{@link #poll poll()}
inspectpeek()element()Examine{@link #element element()}{@link #peek peek()}
+ * * *

Queues typically, but do not necessarily, order elements in a * FIFO (first-in-first-out) manner. Among the exceptions are