Java + Groovy: Creating Immutable List

// class java.util.Arrays$ArrayList
final List mutableList = Arrays.asList(1, 2, 3);

// class java.util.Collections$UnmodifiableRandomAccessList
final List immutableList = Collections.unmodifiableList(Arrays.asList(1, 2, 3));

// class com.google.common.collect.RegularImmutableList
final ImmutableList guavaImmutableList = ImmutableList.of(1, 2, 3);

// class java.util.Collections$UnmodifiableRandomAccessList
final def groovyImmutableList = [1, 2, 3].asImmutable()