- A
The services module is using an automatic module, which automatically reads the unnamed module, while the web module is a named module that does not.
Why wrong: Even if the services module were automatic, the web module being named still cannot access the class path package if it is split.
- B
The class path is not scanned for JAR files unless the module path is empty.
Why wrong: The class path is always scanned for classes, but named modules cannot access classes from the class path if the package is split.
- C
The web module is a named module and cannot access classes from a split package that is also in the unnamed module.
The module system prevents named modules from accessing split packages from the class path to maintain reliable configuration.
- D
The core module's module-info.java does not export the package to the web module; it only exports it to all modules.
Why wrong: The export to all modules should allow the web module to access it, but the issue is the split package, not the export.
Quick Answer
The answer is that the web module, as a named module on the module path, cannot access classes from a split package that also exists in the unnamed module on the class path. This is because the Java module system strictly forbids split packages—where the same package is defined in both a named module and the unnamed module—to prevent class loading ambiguity and encapsulation violations. When the conflicting JAR was moved to the class path, its package became part of the unnamed module, but the core module already exports that same package as a named module. Since the web module requires core, the module system sees the split and blocks access from the unnamed module, causing the ClassNotFoundException. On the Oracle Certified Professional Java SE 17 Developer 1Z0-829 exam, this tests your understanding of module path versus class path interaction and the split package rule, a common trap where candidates assume moving a JAR to the class path always fixes conflicts. Remember: a named module cannot see a split package from the unnamed module—think of it as “named modules are blind to split packages on the class path.”
1Z0-829 Java Platform Overview and Packaging Practice Question
This 1Z0-829 practice question tests your understanding of java platform overview and packaging. 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 team is developing a large enterprise application using Java 17. The application consists of multiple modules: core (provides logging and configuration), services (business logic), and web (REST endpoints). The modules are packaged as separate JAR files and deployed on a server. During runtime, the web module throws a java.lang.ClassNotFoundException for a class that is part of the core module. The core module's module-info.java exports the package containing the missing class. The web module's module-info.java requires core. However, the services module also needs the same class but uses a different version of it, causing conflicts. The team decides to use the class path for the conflicting package and the module path for the rest. They add the conflicting JAR to the class path and keep the other JARs on the module path. After this change, the web module still cannot find the class, but the services module works fine. What is the most likely cause of the issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The web module is a named module and cannot access classes from a split package that is also in the unnamed module.
Option C is correct because when a named module (the web module) is on the module path, it cannot access classes from the unnamed module (the class path) if those classes belong to a package that is also exported by another named module on the module path. This creates a split package, which is forbidden by the Java module system. The core module exports the package, so the web module cannot load the class from the class path JAR, resulting in ClassNotFoundException.
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.
- ✗
The services module is using an automatic module, which automatically reads the unnamed module, while the web module is a named module that does not.
Why it's wrong here
Even if the services module were automatic, the web module being named still cannot access the class path package if it is split.
- ✗
The class path is not scanned for JAR files unless the module path is empty.
Why it's wrong here
The class path is always scanned for classes, but named modules cannot access classes from the class path if the package is split.
- ✓
The web module is a named module and cannot access classes from a split package that is also in the unnamed module.
Why this is correct
The module system prevents named modules from accessing split packages from the class path to maintain reliable configuration.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The core module's module-info.java does not export the package to the web module; it only exports it to all modules.
Why it's wrong here
The export to all modules should allow the web module to access it, but the issue is the split package, not the export.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think the issue is about module visibility (exports) or class path scanning order, but the real constraint is the split package rule, which prevents a named module from accessing a package that is already defined by another named module on the module path.
Detailed technical explanation
How to think about this question
Under the Java module system, a split package occurs when a package is defined in both a named module and the unnamed module (or in multiple named modules). The JPMS (Java Platform Module System) strictly prohibits split packages to ensure reliable configuration and encapsulation. When the web module requires the core module, it sees the package as belonging to the core module, so any attempt to load the same package from the class path is blocked, leading to ClassNotFoundException. This is enforced by the module layer at runtime, not by the class loader alone.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
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.
- →
Java Platform Overview and Packaging — study guide chapter
Learn the concepts, then practise the questions
- →
Java Platform Overview and Packaging practice questions
Targeted practice on this topic area only
- →
All 1Z0-829 questions
509 questions across all exam domains
- →
Oracle Certified Professional Java SE 17 Developer 1Z0-829 study guide
Full concept coverage aligned to exam objectives
- →
1Z0-829 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 1Z0-829 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Handling Date, Time, Text, Numeric and Boolean Values practice questions
Practise 1Z0-829 questions linked to Handling Date, Time, Text, Numeric and Boolean Values.
Controlling Program Flow practice questions
Practise 1Z0-829 questions linked to Controlling Program Flow.
Utilizing Java Object-Oriented Approach practice questions
Practise 1Z0-829 questions linked to Utilizing Java Object-Oriented Approach.
Handling Exceptions practice questions
Practise 1Z0-829 questions linked to Handling Exceptions.
Working with Arrays and Collections practice questions
Practise 1Z0-829 questions linked to Working with Arrays and Collections.
Working with Streams and Lambda Expressions practice questions
Practise 1Z0-829 questions linked to Working with Streams and Lambda Expressions.
Java Platform Overview and Packaging practice questions
Practise 1Z0-829 questions linked to Java Platform Overview and Packaging.
Java I/O API and Securing Applications practice questions
Practise 1Z0-829 questions linked to Java I/O API and Securing Applications.
1Z0-829 fundamentals practice questions
Practise 1Z0-829 questions linked to 1Z0-829 fundamentals.
1Z0-829 scenario practice questions
Practise 1Z0-829 questions linked to 1Z0-829 scenario.
1Z0-829 troubleshooting practice questions
Practise 1Z0-829 questions linked to 1Z0-829 troubleshooting.
Practice this exam
Start a free 1Z0-829 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 1Z0-829 question test?
Java Platform Overview and Packaging — This question tests Java Platform Overview and Packaging — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The web module is a named module and cannot access classes from a split package that is also in the unnamed module. — Option C is correct because when a named module (the web module) is on the module path, it cannot access classes from the unnamed module (the class path) if those classes belong to a package that is also exported by another named module on the module path. This creates a split package, which is forbidden by the Java module system. The core module exports the package, so the web module cannot load the class from the class path JAR, resulting in ClassNotFoundException.
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.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Same concept, more angles
1 more ways this is tested on 1Z0-829
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A developer is migrating a classpath-based application to modules. They have two JARs on the classpath that both contain a package with the same name, com.example.util. When they move both JARs to the module path, they encounter a module resolution error. What is the most likely cause?
hard- A.The --add-exports option is missing
- ✓ B.Named modules cannot have split packages
- C.The JARs need to be merged into one module
- D.Automatic modules cannot have split packages
Why B: In the Java module system, a package can be defined in at most one module on the module path. When both JARs contain com.example.util, moving them to the module path creates a split package, which is illegal for named modules. The module system enforces this to ensure reliable configuration and encapsulation, resulting in a module resolution error.
Last reviewed: Jun 11, 2026
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.