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Java SE 21 Developer
The Oracle Certified Professional: Java SE 21 Developer exam validates a developer's ability to design, implement, and debug complex applications using the Java 21 platform
- 120 min
- 68% to pass
- 50 bank questions
- 11 domains
certilumExam syllabus, organized by domain
The official Oracle blueprint, with the real weight each domain carries on test day.
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Answer one question from the live bank. Grading happens on our servers, so the answer key never reaches the page.
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Sample Java SE 21 Developer exam question
Answer this question the same way you would on exam day. No sign-up needed — one random question, three tries to swap it out.
A credit-check pipeline performs three independent remote score lookups, producing CompletableFuture<Result> f1, f2, and f3. The team needs a single CompletableFuture<List<Result>> that completes only after every lookup succeeds, and this composite future will be passed to the next non-blocking pipeline stage. Given that exceptions are handled by a later exceptionally call, which two snippets correctly construct that composite future without polling or blocking?
Exam facts at a glance
Every figure below comes from the certification record or from the question bank itself.
- Time limit
- 120 minutes
- Passing score
- 68%
- Domains
- 11
- Questions in our bank
- 50
- Level
- PROFESSIONAL
- Measured complexity
- 2.1 / 10
- Question mix
- 20 single · 18 multi · 12 interactive
Where the hard questions actually are
We score every question in the bank 1-10 on a reproducible formula. Below is the per-domain breakdown.
- Arrays and Collections5 questions · complexity 2.0/10 · Gentle
40% multi-select · 0% scenario · 20% interactive
- Concurrency8 questions · complexity 2.0/10 · Gentle
38% multi-select · 0% scenario · 25% interactive
- Controlling Program Flow2 questions · complexity 2.0/10 · Gentle
50% multi-select · 0% scenario · 0% interactive
- Handling Date, Time, Text, Numeric and Boolean Values4 questions · complexity 1.5/10 · Gentle
25% multi-select · 0% scenario · 25% interactive
- Handling Exceptions4 questions · complexity 2.3/10 · Gentle
25% multi-select · 25% scenario · 25% interactive
- I/O and NIO.23 questions · complexity 2.0/10 · Gentle
33% multi-select · 0% scenario · 33% interactive
- Localization2 questions · complexity 2.0/10 · Gentle
50% multi-select · 0% scenario · 0% interactive
- Modules and Deployment3 questions · complexity 2.0/10 · Gentle
33% multi-select · 0% scenario · 33% interactive
- Object-Oriented Concepts11 questions · complexity 2.4/10 · Gentle
45% multi-select · 0% scenario · 27% interactive
- Streams and Lambda Expressions6 questions · complexity 2.0/10 · Gentle
33% multi-select · 0% scenario · 33% interactive
- Supplementary Topics2 questions · complexity 2.0/10 · Gentle
50% multi-select · 0% scenario · 0% interactive
Read the questions before you take them
The question bank with the correct answer and a written explanation for every item.
Frequently asked questions
What you need to know before attempting the Java SE 21 Developer certification.
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