Java SE 11 Dumps & 1Z0-819 Sample Questions for Certification Prep

Get ready for the Oracle Certified Professional Java SE 11 Developer exam with our expertly compiled Java SE 11 Dumps & 1Z0-819 Sample Questions Designed to mirror the actual test format, these resources cover core Java concepts like OOP, modules, APIs, lambdas, and exception handling. Whether you're preparing with the official syllabus or looking for updated 1Z0-819 dumps, this guide helps streamline your preparation with real-world scenarios and accurate question sets. Gain confidence with Java SE 11 certification dumps, developer-focused mock exams, and practice questions that simulate exam difficulty. Ideal for both self-paced learners and professionals aiming to pass the 1Z0-819 exam on the first attempt.

Java SE 11 Dumps & 1Z0-819 Sample Questions List :

1. You are tasked with improving the performance of a multi-threaded Java application. The application experiences frequent contention and performance bottlenecks due to synchronized blocks. Which of the following solutions would best address these issues?

1. Use AtomicInteger for counters instead of synchronized methods.

2. Implement busy-waiting to avoid thread blocking.

3. Employ a single-threaded executor to eliminate contention.

4. Increase the thread priority to reduce contention.

2. You are developing a Java application that processes a large batch of user data. Each user record must be validated, transformed, and then stored in a database. The processing needs to be efficient and able to handle millions of records. Which approach would be the most appropriate to ensure scalability and maintainability of the application?

1. Use a ForkJoinPool to process the records in parallel.

2. Use synchronized blocks to ensure thread safety when accessing the database.

3. Use Thread.sleep() to manage the load on the database.

4. Use a single-threaded process to handle all records sequentially.

3. You are designing a banking application where customer information must be stored securely. Which approach ensures that the customer's account balance cannot be modified after initialization?

1. Allow direct access to the account balance through a protected keyword.

2. Declare the account balance as a public static variable.

3. Implement a getter method to return the account balance.

4. Use a final keyword when declaring the account balance variable.

4. You are developing a Java application that needs to manage database transactions to ensure data integrity and handle concurrency effectively. What is the most effective way to manage transactions in a JDBC application to ensure that all operations within a transaction either succeed or fail as a unit?

1. Using Statement objects to execute SQL queries and manually controlling transaction boundaries with SQL commands.

2. Enabling auto-commit mode on the Connection object at the start of each transaction.

3. Setting the auto-commit mode to false on the Connection object and managing commit and rollback operations explicitly.

4. Relying on the database's default transaction settings to manage commit and rollback operations.

5. You are designing a Java application that requires the secure transfer of data between clients and servers over a network. Which of the following techniques ensures data confidentiality and integrity during transmission?

1. Use plain sockets for network communication

2. Use HTTP protocol for data transfer

3. Use HTTPS protocol with SSL/TLS

4. Use FTP protocol for file transfers

6. In the Java Platform Module System, if you are developing a modular application with a module com.example.service that provides a service used by other modules, which directive should you include in your module-info.java to declare that your module provides this service?

1. exports com.example.service

2. uses com.example.service

3. provides com.example.service with com.example.serviceimpl

4. requires com.example.service

7. You are working on a banking application where multiple threads need to update the same account balance. To ensure thread safety, which of the following options will you use?

1. CopyOnWriteArrayList for the account balance

2. AtomicInteger for the account balance

3. ReentrantLock in the account class

4. synchronized method in the account class

8. You are developing a multi-threaded application that processes a large list of transactions. Each transaction needs to be processed by multiple threads concurrently to improve performance. The processing involves reading data from a shared resource and updating the transaction status. Proper synchronization is necessary to avoid data corruption. Which Java concurrency utility would best ensure that your multi-threaded application processes transactions correctly without data corruption?

1. CountDownLatch

2. synchronized blocks

3. ReentrantLock

4. AtomicInteger

9. In a Java application, you need to serialize an object of class Employee to save its state to a file. The Employee class implements Serializable. Which method should you use to serialize an Employee object to a file correctly?

1. Use FileWriter.write() directly on the Employee object.

2. Use ObjectOutputStream.writeObject() after wrapping it with a FileOutputStream.

3. Use PrintStream.print() on the Employee object.

4. Use DataOutputStream.writeBytes() after converting the Employee object to bytes.

10. In a Java SE 11 application, a developer needs to manage a high-throughput, low-latency logging system that can handle concurrent log entries without data loss. Which approach ensures the best performance while maintaining thread safety?

1. Employ simple locking mechanisms with the ReentrantLock class.

2. Use a synchronized ArrayList to store log entries.

3. Write log entries directly to a database using JDBC without caching.

4. Utilize java.util.concurrent.ConcurrentHashMap to manage log entries.

11. You are developing a Java application that processes large amounts of financial data. One of the requirements is to ensure the precision of decimal values, especially when dealing with currency calculations. You decide to use the BigDecimal class for this purpose. Which two of the following statements about the BigDecimal class and its usage are correct?

1. BigDecimal is immutable and provides precise control over decimal numbers.

2. Using BigDecimal(double val) constructor might lead to unpredictable precision errors.

3. BigDecimal class can be used with primitive data types like int and double directly without conversion.

4. BigDecimal values are mutable and can be changed after creation.

5. BigDecimal supports basic arithmetic operations such as addition and multiplication using operator overloading.

12. Which of the following statements about the usage of List, Set, and Map collections and their convenience methods is correct?

1. Set.add(null) will throw a NullPointerException if the set is created using Set.of().

2. Map.replace("key", "newValue") adds the key-value pair if the key does not exist.

3. List.of("A", "B", "C") creates a mutable list.

4. List.addAll(Collection<? extends E> c) throws a ClassCastException if elements are of a different type.

13. Consider a Java application where you need to manage transactions across multiple databases and messaging systems. The application must ensure data consistency across all systems in case of a failure. Which Java feature or technology is most suitable for implementing this requirement?

1. JavaBeans Activation Framework (JAF)

2. Java Database Connectivity (JDBC)

3. Java Transaction API (JTA)

4. Java Naming and Directory Interface (JNDI)

14. You are working on a Java application that requires concurrent processing of several long-running tasks. You need to ensure that the tasks are efficiently managed and the results are collected once they complete. Which steps would you take to implement this?

1. Use ExecutorService to submit Runnable tasks and use Thread.sleep() to periodically check for task completion.

2. Use ExecutorService to submit Callable tasks and retrieve results using Future.

3. Use ThreadLocal variables to store results from Runnable tasks and retrieve them after all threads complete.

4. Use ScheduledExecutorService to submit Runnable tasks for immediate execution and manage completion manually.

15. You are tasked with designing a utility class that provides configuration settings for various parts of an application. The settings are loaded once and do not change during the application's runtime. Which design approach best utilizes static and instance methods for the described utility class?

1. Use static methods to load settings into static fields and static methods to retrieve these settings.

2. Use static methods to load and retrieve settings, and instance fields to store these settings.

3. Use instance methods and fields to load and retrieve settings, and create a new instance of the class each time settings are accessed.

4. Use instance methods to load settings into instance fields and require each part of the application to maintain its own instance.

16. You are deploying a modular Java application with three modules: com.example.app, com.example.utils, and com.example.logging. The com.example.app module requires both com.example.utils and com.example.logging. How should you define the module-info.java files to ensure proper dependency management?

1. In com.example.utils, declare requires com.example.app; and in com.example.logging, declare requires com.example.app;.

2. In com.example.app, declare requires com.example.utils; and requires com.example.logging;.

3. In com.example.app, declare requires transitive com.example.utils; and in com.example.logging, declare requires com.example.app;.

4. In com.example.app, declare requires com.example.utils; and requires transitive com.example.logging;.

17. You are developing an application that needs to read sensitive configuration files from the filesystem. To securely access these files and ensure that only authorized code can read them, which approach should you use?

1. Use environment variables to store file paths and read them directly

2. Use FileReader directly to read the files

3. Store the configuration files in a publicly accessible directory

4. Use the Security Manager and define appropriate policies in a policy file

18. You are maintaining a legacy application where multiple threads interact with a shared resource. You need to refactor the code to prevent race conditions while minimizing changes to the structure of the existing code. Which locking mechanism is most appropriate to ensure thread safety with minimal changes to the existing codebase?

1. Use ReentrantReadWriteLock to manage read and write access separately.

2. Replace method-level synchronization with block-level synchronization using the synchronized keyword.

3. Implement locking using the Lock interface from java.util.concurrent.locks.

4. Apply StampedLock for optimistic reads and conditional writes.

19. You are designing a software system for an online learning platform. The system needs to handle different types of courses, such as live sessions and recorded sessions. You decide to use a class hierarchy to represent these different course types, utilizing abstract classes and inheritance. Which of the following design choices would best adhere to Java object-oriented principles for creating and using subclasses and superclasses?

1. Define a Course superclass with concrete methods and extend it with LiveCourse and RecordedCourse without overriding any methods.

2. Use interfaces LiveSession and RecordedSession and implement these interfaces in the Course class.

3. Create an abstract class Course with abstract methods start and end, and extend it with LiveCourse and RecordedCourse classes implementing these methods.

4. Define a single Course class with methods for both live and recorded session functionalities.

5. Create an abstract class Course with a mix of abstract and concrete methods, and extend it with LiveCourse and RecordedCourse classes, providing specific implementations where necessary.

20. You are deploying and executing a modular Java application that consists of several modules. One of your modules, com.example.app, relies on an automatic module. The automatic module is created from a third-party library JAR file, thirdparty-lib.jar, which does not have a module-info.java file. The command to run your application is as follows: java --module-path libs:thirdparty-lib.jar --module com.example.app/com.example.app.Main Given this scenario, which of the following statements are correct? (Choose two)

1. The derived module name of thirdparty-lib.jar is based on the JAR file name.

2. The com.example.app module can require the automatic module using its derived module name.

3. The thirdparty-lib.jar must contain a module-info.class file to be used as an automatic module.

4. The thirdparty-lib.jar is treated as an automatic module by the module system.

5. The com.example.app module cannot access the thirdparty-lib.jar because it lacks a module-info.java file.

21. You are designing an application where various classes need to perform operations related to encryption and decryption. Which Java feature allows you to define a contract specifying methods for encryption and decryption, which each implementing class must fulfill?

1. Abstract class

2. Singleton pattern

3. Interface

4. Constructor chaining

22. You are developing a Java application that manages a library system. Each book has multiple copies, and each copy can be checked out by library members. Which Java feature should you use to represent the relationship between books and their copies, ensuring efficient management of checkouts?

1. Nested classes

2. Interfaces

3. Inheritance

4. Enums

23. You are designing a multi-threaded application where a critical section of code needs to be accessed by only one thread at a time. Which mechanism should you use to achieve this in Java?

1. AtomicBoolean class

2. CountDownLatch class

3. volatile keyword

4. synchronized keyword

24. You are developing a Java application that processes financial transactions in a highly concurrent environment. You use a ConcurrentHashMap to store transaction records. During peak times, you observe contention and performance degradation. Which strategy should you implement to reduce contention while ensuring thread safety?

1. Use a CopyOnWriteArrayList to store transaction records.

2. Increase the concurrency level of the ConcurrentHashMap by adjusting its constructor parameters.

3. Use Collections.synchronizedMap instead of ConcurrentHashMap.

4. Replace ConcurrentHashMap with HashMap and synchronize the critical sections manually.

FAQs

1. What is the Oracle Certified Professional Java SE 11 Developer 1Z0-819 certification?

It is Oracle’s professional-level certification that validates advanced skills in Java programming, covering APIs, modularity, security, and performance.

2. How do I become Oracle Certified Professional Java SE 11 Developer 1Z0-819 certified?

You must prepare using Java SE 11 materials, register for the 1Z0-819 exam through Oracle, and pass it.

3. What are the prerequisites for the Oracle 1Z0-819 Java SE 11 certification?

There are no mandatory prerequisites, but solid Java programming knowledge is recommended.

4. How much does the Oracle Java SE 11 Developer 1Z0-819 exam cost?

The exam fee is $245 USD.

5. How many questions are on the Oracle 1Z0-819 certification exam?

The exam includes 50 multiple-choice questions.

6. What is the passing score for the Oracle Java SE 11 Developer 1Z0-819 exam?

You need at least 68% to pass.

7. How long is the Oracle 1Z0-819 certification exam?

The exam duration is 90 minutes.

8. What topics are covered in the Oracle Certified Professional Java SE 11 Developer exam?

It covers OOP, modularity, annotations, concurrency, security, JDBC, generics, and functional programming with streams.

9. How difficult is the Oracle Java SE 11 Developer 1Z0-819 exam?

It is considered challenging, requiring strong coding practice and theoretical knowledge.

10. How long does it take to prepare for the 1Z0-819 certification exam?

Most candidates take 8–12 weeks of consistent study and practice.

11. Are there any Oracle 1Z0-819 sample questions or practice tests available?

Yes, Oracle provides examples, and CertiMaan offers dumps and practice tests.

12. What is the validity period of the Oracle Java SE 11 Developer 1Z0-819 certification?

The certification is valid for life, but updating with newer Java versions is recommended.

13. Can I retake the Oracle 1Z0-819 exam if I fail?

Yes, you can retake after paying the exam fee again.

14. What jobs can I get with an Oracle Java SE 11 Developer 1Z0-819 certification?

You can work as a Java Developer, Software Engineer, Backend Developer, or Application Developer.

15. How much salary can I earn with an Oracle Certified Professional Java SE 11 Developer certification?

Certified professionals typically earn $80,000–$120,000 annually, depending on role and region.

16. Is the Oracle 1Z0-819 Java SE 11 certification worth it?

Yes, it is highly respected in the industry and boosts career prospects in enterprise software development.

17. What is the difference between Oracle 1Z0-819 and 1Z0-817 Java certifications?

• 1Z0-817: For upgrading from Java SE 8 OCP.

• 1Z0-819: Direct exam for full Java SE 11 OCP certification.

18. What are the best study materials for the Oracle Java SE 11 Developer 1Z0-819 exam?

Use Oracle’s Java SE 11 documentation, official guides, and CertiMaan practice resources.

19. Does Oracle provide official training for the 1Z0-819 Java certification?

Yes, Oracle offers online and instructor-led training courses.

20. Where can I register for the Oracle Certified Professional Java SE 11 Developer 1Z0-819 exam?

You can register through the Oracle Certification Exam Portal.