Java - Find Element in Array using Condition and Lambda

Question

In short, I have this code, and I'd like to get an specific element of the array using a condition and lambda. The code would be something like this:

Preset[] presets = presetDALC.getList(); Preset preset = Arrays.stream(presets).select(x -> x.getName().equals("MyString")); 

But obviously this does not work. In C# would be something similar but in Java, how do I do this?

Answer 1

You can do it like this,

Optional<Preset> optional = Arrays.stream(presets)                                    .filter(x -> "MyString".equals(x.getName()))                                    .findFirst();  if(optional.isPresent()) {//Check whether optional has element you are looking for     Preset p = optional.get();//get it from optional } 

You can read more about Optional here.

Answer 2

Like this:

Optional<Preset> preset = Arrays         .stream(presets)         .filter(x -> x.getName().equals("MyString"))         .findFirst(); 

This will return an Optional which might or might not contain a value. If you want to get rid of the Optional altogether:

Preset preset = Arrays         .stream(presets)         .filter(x -> x.getName().equals("MyString"))         .findFirst()         .orElse(null); 

The filter() operation is an intermediate operation which returns a lazy stream, so there's no need to worry about the entire array being filtered even after a match is encountered.