似乎Multiset中应该有一个removingAllOccuring(Collection)(或类似的)方法。类似于remove(Object,int)和removeAll(Collection)。缺少这种方法,实现其意图的最佳方法是什么。我写了一个小的 JUnit 驱动来演示:
/**
* @see http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/Multiset.html
* @see http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/HashMultiset.html
*/
@Test
public void testBag() {
Multiset<String> bag1 = HashMultiset.create();
bag1.add("a", 2);
bag1.add("b", 3);
bag1.add("c", 3);
logger.debug(bag1);
Multiset<String> bag1Copy = HashMultiset.create(bag1);
Multiset<String> bag2 = ImmutableMultiset.of("a","b","b","b","c","c");
Multiset<String> expected = ImmutableMultiset.of("a","c");
for( String el : bag2.elementSet() ) {
bag1.remove( el, bag2.count(el));
} // end for
Assert.assertEquals(expected, bag1);
bag1Copy.removeAll(bag2);
logger.debug( bag1Copy );
}
输出:
[b x 3, c x 3, a x 2]
[]
我在想可能有一种方法,前提是我丢失了,或者有一种不同/更好的方法,而不是循环遍历要删除的集合。另请注意,我可以很容易地有一个用例,其中要删除的集合是List