Which interface in the Java Collections Framework represents a group of objects where duplicates are not allowed?
Map
List
Queue
Set
How can you get the current year using the java.time API?
java.time
LocalTime.now().getYear()
Calendar.getInstance().get(Calendar.YEAR)
Year.now()
LocalDate.now().getYear()
Which Java method would you use to find the index of the first occurrence of a specific substring within a string?
length()
indexOf()
charAt()
substring()
What is the core function of an 'ExecutorService' in Java's concurrency framework?
To manage and execute thread pools efficiently
To schedule tasks for execution at fixed intervals
To define custom locking mechanisms
To synchronize access to shared resources
Which keyword is used to create a generic method in Java?
generic
No specific keyword is required
template
typeparam
What does the 'E' typically represent in a generic type parameter like 'List<E>'?
Enum
Exception
Element
Entry
Which interface must a class implement to be eligible for serialization in Java?
Serializable
Iterable
Cloneable
Parcelable
What happens when a Stream encounters an exception during execution?
The exception is ignored, and the stream continues processing
The stream processing stops, and the exception is thrown
The exception is caught and wrapped in a RuntimeException
The stream processing pauses, and the user is prompted to handle the exception
Which List implementation in Java uses a dynamic array to store elements and provides fast access to elements by their index?
Vector
LinkedList
ArrayList
Stack
What is the most suitable approach to ensure that a specific block of code is executed by only one thread at a time?
Using the 'volatile' keyword
Declaring the variable as 'final'
Implementing the 'Serializable' interface
Using a 'synchronized' block or method