I have a List of object and the list is very big. The object is
class Sample { String value1; String value2; String value3; String value4; String value5; }
Now I have to search for a specific value of an object in the list. Say if value3=='three'
I have to return those objects (My search is not always based on value3)
The list is
List<Sample> list = new ArrayList<Sample>();
What is the efficient way of doing it?
Thanks.
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Answer
You can give a try to Apache Commons Collections.
There is a class CollectionUtils that allows you to select or filter items by custom Predicate.
Your code would be like this:
Predicate condition = new Predicate() { boolean evaluate(Object sample) { return ((Sample)sample).value3.equals("three"); } }; List result = CollectionUtils.select( list, condition );
Update:
In java8, using Lambdas and StreamAPI this should be:
List<Sample> result = list.stream() .filter(item -> item.value3.equals("three")) .collect(Collectors.toList());
much nicer!