Concurrency & language in the Java assessment

What it covers

Exceptions and resource management, streams and lambdas, functional interfaces, null safety and the basics of concurrent code.

Topics in the practice set for this area

• exceptions
• concurrency
• resource management
• streams
• functional interfaces
• lambdas
• null safety

How it is tested

In the timed assessment, questions in this area use these formats: code you write, multiple choice, put the steps in order, short answer, written scenario. Each attempt draws its own set of questions, and this area gets its own sub-score on the credential when the attempt includes enough questions from it. The assessment questions themselves are never published; the practice set below is written separately for study.

What to practice

• Use try-with-resources and know which exceptions must be declared.
• Rewrite a loop as a stream pipeline and back again.
• Explain a race condition in a shared counter and fix it two different ways.

Try a practice question

From the free practice set (8 questions in this area). Answers and explanations are in the practice set.

• A method calls `Files.readString(path)`, which declares `throws IOException`. What does the compiler require of that method?
• `ConcurrentHashMap` is preferred over `Hashtable` because:
• `try-with-resources` closes a resource by:

More Java study guides

• How to Pass the Provyn Java Assessment
• Object model & collections
• JVM & performance