CODEWITHSUNDEEP
javalistcollectionsjava-7
Vikas Singh
Vikas Singh

Reputation: 3018

find Unique Object matching a property value using Java 7

I have a list of Entity, all entities have unique name, currently to get unique value, I am using MAP of entity name and Entity Object. I dont want to use map just for filter purpose.

I found one solution, but it usage Java-8.

There is one API in Google Guava com.google.common.collect.Sets.filter(), but it returns Set and in this case I have to get 0th element.

Can anyone suggest better approach.

Upvotes: 0

Views: 375

Answers (2)

Himanshu Bhardwaj
Himanshu Bhardwaj

Reputation: 4113

Using the Map approach gives you time benefit as lookup time is reduced whereas, but uses memory.

If you are open to Guava try something like:

Optional<Entity> result = FluentIterable.from(entityList).firstMatch(new Predicate<Entity>() {
  @Override
  public boolean apply(Entity entity) {
    return entity.getName().equals(input);  //Input can be from variable in function definition
  });
);

Something like this, can solve.

Upvotes: 2

jeet427
jeet427

Reputation: 596

Try below method:

public static Entity findByName(String name, List<Entity> entities) {
        if (entities!= null && name != null) {
            for (Entity e : entities) {
                if (name.equals(e.getName())) {
                    return e;
                }
            }
        }
        return null;
    }

Upvotes: 0

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