1Z0-829 Utilizing Java Object-Oriented Approach Practice Question
This 1Z0-829 practice question tests your understanding of utilizing java object-oriented approach. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A financial services company runs a Java 17 Spring Boot application that processes real-time stock trades. The application uses a class `TradeProcessor` containing a method `void process(Trade trade)`. This method is invoked by multiple threads concurrently. The `Trade` class is immutable and has fields like `String symbol`, `int quantity`, `double price`. The `TradeProcessor` method updates a shared `HashMap<String, Double>` that tracks the average price per symbol. The update logic is: retrieve the current average for the symbol, compute a new average, and put it back. During high-load testing, the average prices are occasionally incorrect. The development team suspects a race condition. Which course of action should be taken to fix the issue with minimal performance impact?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Replace `HashMap` with `ConcurrentHashMap` and use the `compute` method to atomically update the average.
Option B is correct because `ConcurrentHashMap` provides thread-safe atomic operations like `compute`, which allows you to atomically update the average price per symbol without external synchronization. This avoids the race condition where two threads read the same old average, compute a new one, and overwrite each other's result. Using `compute` ensures the read-modify-write sequence is performed atomically, with minimal performance overhead compared to synchronizing the entire method.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Use an `AtomicReference` to wrap the `HashMap`.
Why it's wrong here
AtomicReference provides atomic reference updates but not atomic updates to the map's entries.
✓
Replace `HashMap` with `ConcurrentHashMap` and use the `compute` method to atomically update the average.
Why this is correct
ConcurrentHashMap provides atomic compute methods suitable for this scenario without explicit locking.
Related concept
Read the scenario before looking for a memorised answer.
✗
Synchronize the entire `process` method.
Why it's wrong here
Method-level synchronization would cause high contention and reduce throughput.
✗
Change the `HashMap` to `Hashtable`.
Why it's wrong here
Hashtable synchronizes individual operations but not compound actions, so race condition remains.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think `ConcurrentHashMap` alone solves all concurrency issues, but without using atomic methods like `compute`, `merge`, or `replace`, the read-modify-write race condition persists; the exam tests whether you know that `ConcurrentHashMap`'s per-operation thread safety does not automatically compose into atomic compound actions.
Detailed technical explanation
How to think about this question
Under the hood, `ConcurrentHashMap.compute` uses internal locking on specific hash buckets (via synchronized blocks on `Node` objects) rather than locking the entire map, allowing concurrent updates to different keys. The `compute` method retries if the bucket is locked, ensuring atomicity without blocking unrelated threads. In a real-world stock trading system, this approach scales well because trades for different symbols can be processed in parallel, while trades for the same symbol are serialized only at the bucket level.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 1Z0-829 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Utilizing Java Object-Oriented Approach — This question tests Utilizing Java Object-Oriented Approach — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Replace `HashMap` with `ConcurrentHashMap` and use the `compute` method to atomically update the average. — Option B is correct because `ConcurrentHashMap` provides thread-safe atomic operations like `compute`, which allows you to atomically update the average price per symbol without external synchronization. This avoids the race condition where two threads read the same old average, compute a new one, and overwrite each other's result. Using `compute` ensures the read-modify-write sequence is performed atomically, with minimal performance overhead compared to synchronizing the entire method.
What should I do if I get this 1Z0-829 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 1Z0-829 practice question is part of Courseiva's free Oracle certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 1Z0-829 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.