Guava 19.0 RC2 发布，Google 的常用 Java 类

发布于 2015-09-18 17:54:26 | 349 次阅读 | 评论: 0 | 来源: 网友投递

Google Guava Collections 是一个对 Java Collections Framework 增强和扩展的一个开源项目。由于它高质量 API 的实现和对 JDK5 特性的充分利用，使得其在 Java 社区受到很高评价。笔者主要介绍它的基本用法和功能特性。

Guava 19.0 RC2 发布，此版本值得关注的 API 改进如下：

Added CharMatcher static factory methods equivalent to the CharMatcher constants. For example, added CharMatcher.whitespace() which is equivalent to CharMatcher.WHITESPACE. Eventually, the constants will be deprecated and removed.
- This is being done because using constants requires a large number of classes to be initialized when anything from CharMatcher is used; switching to static factory methods allows classes to be initialized only as needed for the type of CharMatcher actually being used.
Added Throwables.lazyStackTrace(Throwable) - Returns a List<StackTraceElement> that may load the stack trace elements lazily. Useful if you want to get only the first N elements of the stack trace efficiently.
Added lazyStackTraceIsLazy()- Returns whether or not the above method is able to use the special implementation that makes it lazy on the current platform.
Added VerifyException constructor overloads taking a Throwable cause.

This package has graduated from @Beta, making it safe to use in library code.

Added visibility of CacheLoader.UnsupportedLoadingOperationException
Added RemovalNotification.create
- These should only be needed if creating a custom cache implementation

Added factory and builder methods for various ImmutableMaps and ImmutableMultimaps that take Iterable<Map.Entry>.

Added FluentIterable.toMultiset()
Added RangeSet.asDescendingSetOfRanges() and RangeMap.asDescendingMapOfRanges()
Added Lists.cartesianProduct(List...) and Lists.cartesianProduct(List<List>>)
Added Maps.newLinkedHashMapWithExpectedSize(int)
Re-added Multisets.removeOccurrences(Multiset, Multiset) which was (binary incompatibly) missing in 18.0 because it was replaced with Multisets.removeOccurences(Multiset, Iterable)
Deprecated MapConstraint and MapConstraints
Deprecated Sets.newSetFromMap(Map) - Java 6 provides Collections.newSetFromMap(Map)
Removed MapMaker.softValues()

Added EventBus.identifier()
Removed protected method AsyncEventBus.dispatchQueuedEvents() (made package-private)

Added BloomFilter.create overloads taking a long for the expectedInsertions
Added Hashing.sha384()
Added Hashing.concatenating(HashFunction, HashFunction, HashFunction...) and Hashing.concatenating(Iterable<HashFunction>)

Added TypeToken.isSubtypeOf(TypeToken), TypeToken.isSupertypeOf(TypeToken) and overloads of both that take a Type
Deprecated TypeToken.isAssignableFrom(TypeToken) and TypeToken.isAssignableFrom(Type) - isSupertypeOf provides equivalent behavior with a less confusing name

Futures.getChecked, the replacement for Futures.get (see below), has become stricter. It now rejects calls that pass an unsuitable exception type, even if the input Future succeeded. Previously, it would reject only calls in which the input Future had failed.
Added AbstractFuture.newCancellationCause()
Added AbstractFuture.setFuture(ListenableFuture)
Added Futures.getChecked
Added Futures.catching and Futures.catchingAsync
Added Futures.transformAsync
Added Futures.withTimeout
Deprecated FutureFallback and Futures.withFallback methods - these are replaced with Futures.catching
Deprecated Futures.get methods taking a Class<X extends Exception> - these are replaced with Futures.getChecked
Deprecated Futures.transform methods taking an AsyncFunction - these are replaced with Futures.transformAsync

目前主要包含：