apache-commons-collection

java.lang.NoClassDefFoundError: com.sun.org.apache.commons.beanutils.PropertyUtils

由 这一生的挚爱 提交于 2020-01-16 02:09:35
问题 i am trying to use apache commons collections and predicate as follows: List<Cat> bigList = ....; // master list Collection<Cat> smallList = CollectionUtils.select(bigList, new Predicate() { public boolean evaluate(Object o) { Cat c = (Cat)o; return c.getFavoriteFood().equals("Wiskas") && c.getWhateverElse().equals(Something); } }); and the jars I have in my classpath are: commons-beanutils-1.8.3.jar commons-collections-3.1.jar commons-logging-1.1.jar but in runtime I get the following

Java Commons Collections removeAll

由 十年热恋 提交于 2019-12-31 17:49:10
问题 CollectionUtils::removeAll() Commons Collections 3.2.1 I must be going crazy, becuase it seems like this method is doing the inverse of what the docs state: Removes the elements in remove from collection. That is, this method returns a collection containing all the elements in c that are not in remove. This little JUnit test @Test public void testCommonsRemoveAll() throws Exception { String str1 = "foo"; String str2 = "bar"; String str3 = "qux"; List<String> collection = Arrays.asList(str1,

How do I learn to use Java commons-collections?

由 久未见 提交于 2019-12-22 06:08:06
问题 Weird title, I know, let me explain. I am a developer most familiar with C# and Javascript. I am completely sunk into those semi-functional worlds to the point that most of my code is about mapping/reducing/filtering collections. In C# that means I use LINQ just about everywhere, in Javascript it's Underscore.js and jQuery. I have currently been assigned to an ongoing Java project and am feeling rather stifled. I simply do not think in terms of "create an array, shuffle stuff from one to

What does the arrow operator, '->', do in Java?

由 丶灬走出姿态 提交于 2019-12-16 22:16:26
问题 While hunting through some code I came across the arrow operator, what exactly does it do? I thought Java did not have an arrow operator. return (Collection<Car>) CollectionUtils.select(listOfCars, (arg0) -> { return Car.SEDAN == ((Car)arg0).getStyle(); }); Details : Java 6, Apache Commons Collection, IntelliJ 12 Update/Answer: It turns out that IntelliJ 12 supports Java 8, which supports lambdas, and is "folding" Predicates and displaying them as lambdas. Below is the "un-folded" code.

Is there a viable generic alternative to apache.commons.collections.CollectionUtils?

由 久未见 提交于 2019-12-08 14:47:00
问题 Is there a viable generic version of org.apache.commons.collections.CollectionUtils ? If not, why not? It seems like an obvious need. Or has the Java community just given up on functional coding until closures are added to Java 17? 回答1: There's a genericified port of a slightly out-of-date version of Commons Collections here. It's no longer maintained, however. A better option is Google Guava. It has classes like Lists , Sets , Collections2 etc that are the equivalent to Commons'

Creating a Commons Collections MultiValueMap with a custom value collection type

由 孤街浪徒 提交于 2019-12-07 05:08:20
问题 The 4.0 release of the Apache Commons Collections library has added generics support. I am having trouble converting my code to take advantage of it: I would like a MultiValueMap which takes a String as a key, and a collection of Strings as the value. But: The keys should retain insertion ordering (so I create the multi-valued map by decorating a LinkedHashMap) The values should be unique for each key and retain insertion ordering (so I want the values Collection type to be a LinkedHashSet).

Creating a Commons Collections MultiValueMap with a custom value collection type

由 坚强是说给别人听的谎言 提交于 2019-12-05 09:39:32
The 4.0 release of the Apache Commons Collections library has added generics support. I am having trouble converting my code to take advantage of it: I would like a MultiValueMap which takes a String as a key, and a collection of Strings as the value. But: The keys should retain insertion ordering (so I create the multi-valued map by decorating a LinkedHashMap ) The values should be unique for each key and retain insertion ordering (so I want the values Collection type to be a LinkedHashSet ). The closest I can get is: MultiValueMap<String, String> orderedMap = MultiValueMap.multiValueMap( new

How do I learn to use Java commons-collections?

由 我的未来我决定 提交于 2019-12-05 08:58:11
Weird title, I know, let me explain. I am a developer most familiar with C# and Javascript. I am completely sunk into those semi-functional worlds to the point that most of my code is about mapping/reducing/filtering collections. In C# that means I use LINQ just about everywhere, in Javascript it's Underscore.js and jQuery. I have currently been assigned to an ongoing Java project and am feeling rather stifled. I simply do not think in terms of "create an array, shuffle stuff from one to another". I can (and did) create my own versions of the main map/reduce functions using anonymous types

How to convert a Collection to List?

由 老子叫甜甜 提交于 2019-11-28 02:51:10
I am using TreeBidiMap from the Apache Collections library. I want to sort this on the values which are doubles . My method is to retrieve a Collection of the values using: Collection coll = themap.values(); Which naturally works fine. Main Question: I now want to know how I can convert/cast (not sure which is correct) coll into a List so it can be sorted? I then intend to iterate over the sorted List object, which should be in order and get the appropriate keys from the TreeBidiMap ( themap ) using themap.getKey(iterator.next()) where the iterator will be over the list of doubles . List list

How to convert a Collection to List?

由 两盒软妹~` 提交于 2019-11-27 05:03:05
问题 I am using TreeBidiMap from the Apache Collections library. I want to sort this on the values which are doubles . My method is to retrieve a Collection of the values using: Collection coll = themap.values(); Which naturally works fine. Main Question: I now want to know how I can convert/cast (not sure which is correct) coll into a List so it can be sorted? I then intend to iterate over the sorted List object, which should be in order and get the appropriate keys from the TreeBidiMap ( themap
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