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Oracle 1Z0-819 Exam Practice Questions, practice question pack
ORACLE · 1Z0-819

Oracle 1Z0-819 Exam Practice Questions

99% pass rateUpdated 1 Nov 2026213 questions2 PDFs by email
4.02 reviews
(2 customer reviews)

US$39

Every question with the correct answer and why the other options are wrong.

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TRY BEFORE YOU BUY

Three of the 213 questions in this pack

Question 1

Which two interfaces are considered to be functional interfaces? (Choose two.)

  1. @FunctionalInterface interface InterfaceC { public boolean equals(Object o); int breed(int x); int calculate(int x, int y); }
  2. @FunctionalInterface interface InterfaceD { int breed(int x); }
  3. @FunctionalInterface interface InterfaceE { public boolean equals(int i); int breed(int x); }
  4. interface InterfaceA { int GERM = 13; public default int getGERM() { return GERM; } }
  5. interface InterfaceB { int GERM = 13; public default int getGERM() { return get(); } private int get() { return GERM; } public boolean equals(Object o); int breed(int x); }
Show answer and explanation

Correct answer: B, E. @FunctionalInterface interface InterfaceD { int breed(int x); }; interface InterfaceB { int GERM = 13; public default int getGERM() { return get(); } private int get() { return GERM; } public boolean equals(Object o); int breed(int x); }

A functional interface has exactly one abstract method, and abstract methods that match public methods of Object, such as equals(Object), do not count. InterfaceD has only breed. InterfaceB has default and private methods plus equals(Object), leaving breed as its single abstract method, so it is functional even without the annotation.

Why the other options are wrong

  • A. InterfaceC has two abstract methods, breed and calculate, so the @FunctionalInterface annotation causes a compile error.
  • C. equals(int) does not override Object.equals(Object), so InterfaceE has two abstract methods.
  • D. InterfaceA has no abstract method at all, only a default method and a constant.

Question 2

Which code fragment does a service use to load the service provider with a Print interface?

  1. private java.util.ServiceLoader loader = ServiceLoader.load(Print.class)
  2. private Print print = new com.service.Provider.PrintImpl();
  3. private java.util.ServiceLoader loader = new java.util.ServiceLoader<>()
  4. private Print print = com.service.Provider.getInstance();
Show answer and explanation

Correct answer: A. private java.util.ServiceLoader loader = ServiceLoader.load(Print.class)

ServiceLoader.load(Print.class) is the correct way to load a service provider. It returns a ServiceLoader instance that can iterate over all implementations of the Print service found on the module path or classpath. Option B uses direct instantiation, which bypasses the service provider mechanism. Option C attempts to instantiate ServiceLoader with the diamond operator, which is incorrect syntax and defeats the purpose. Option D uses a static factory method pattern that is not part of the standard ServiceLoader API.

Why the other options are wrong

  • B. Direct instantiation with 'new' bypasses the ServiceLoader mechanism entirely and doesn't support service discovery.
  • C. ServiceLoader cannot be instantiated directly with the diamond operator; it must be loaded via the static load() method.
  • D. The getInstance() pattern is not how ServiceLoader works; ServiceLoader uses the static load() factory method instead.

Question 3

Which three initialization statements are correct? (Choose three.)

  1. int[][][] e = {{1,1,1},{2,2,2}};
  2. short sh = (short)’A’;
  3. float x = 1f;
  4. byte b = 10; char c = b;
  5. String contact# = “(+2) (999) (232)”;
  6. int x = 12_34;
  7. boolean false = (4 != 4);
Show answer and explanation

Correct answer: B, C, F. short sh = (short)’A’;; float x = 1f;; int x = 12_34;

Option B is correct because a char can be initialized with a cast short value, and the cast is valid. Option C is correct because the f suffix denotes a float literal, which is the proper way to initialize a float variable. Option F is correct because numeric literals can use underscores as separators for readability (introduced in Java 7), making 12_34 equivalent to 1234. Option A is incorrect because a 3D array cannot be initialized with a 2D array literal. Option D is incorrect because you cannot assign a byte directly to a char without an explicit cast. Option E is incorrect because identifiers cannot contain the # symbol. Option G is incorrect because false is a reserved keyword in Java and cannot be used as a variable name.

Why the other options are wrong

  • A. A 3D array type cannot be initialized with 2D array literals.
  • D. Byte cannot be assigned to char without an explicit cast.
  • E. The # character is not allowed in identifier names.
  • G. false is a reserved keyword and cannot be used as a variable name.

See all 27 free questions Get the full pack, US$39

REVIEWS

2 reviews for Oracle 1Z0-819 Exam Practice Questions

  1. Jay –

    Java SE 11 Developer Passed with 98% Marks

  2. Burnell –

    They really helped me a lot. Thank you for the dump Java SE 11 Developer

Only logged in customers who have purchased this product may leave a review.

How much of the Oracle 1Z0-819 bank is free?

213 questions in the bank

Each step includes the one before, so buying only adds new questions.

  • You are here10questionsFree sampleThree on this page, all ten as a PDF.Download the sample
  • 2713% of the bankPractice pageFree on the site, every answer explained.Go to the practice page
  • 96the first half of the packHalf PackFree by email, as one PDF, every answer explained.Get the Half Pack
  • 213100%, the whole bankFull pack, US$39Plus the questions-only PDF, monthly updates, refund if you fail.Get the full pack
ABOUT THIS PACK

What’s in the Oracle 1Z0-819 pack

  • 213 questions mapped to the 1Z0-819 exam topics
  • Answers and explanations for every question, including the wrong options
  • A questions-only PDF for timed practice runs
  • Delivered by email shortly after checkout
  • Free monthly updates for as long as the exam is live
  • Pass or your money back

A failed 1Z0-819 attempt means paying the exam fee again. This pack is US$39, paid once.

What makes the 1Z0-819 hard

1Z0-819 is the single exam that replaced the old two-exam Java 11 path, and Oracle compressed 160 questions of material into 50 questions and 90 minutes without dropping any topics. That is why people with years of Java experience fail it: under two minutes per question, most questions are a code listing with a "what is the result" stem, and several have more than one correct answer with no hint of how many to pick. The 68% pass mark sounds gentle until you meet the format.

The exam topics are the whole Java SE 11 language and core library: data types, operators, promotion and casting, program flow; the object-oriented approach with inheritance, polymorphism, interfaces, nested classes and enums; exception handling including try-with-resources and custom exceptions; arrays, collections and generics; streams and lambda expressions with functional interfaces, Optional and collectors; the Java Platform Module System with module declarations, services and migration; concurrency with executors, concurrent collections and thread safety; the Java I/O API including NIO.2 paths and files; secure coding; JDBC with statements, result sets and transactions; localization with locales, resource bundles and formatting; and annotations. Questions on modules, streams and concurrency are where the most time is lost, because they require tracing what the code does rather than recognising a rule.

About the exam

1Z0-819 (Java SE 11 Developer) earns the Oracle Certified Professional: Java SE 11 Developer credential. It covers Java data types, program flow, object-oriented programming, exception handling, arrays and collections, streams and lambdas, the module system, concurrency, I/O, secure coding, JDBC, localization and annotations. No prerequisites. Oracle retires this exam on 30 November 2026.

Questions before you buy

How quickly do I receive it?

Your PDF is prepared and sent to your email address after checkout, and you get a confirmation as soon as it is on its way.

Are updates included?

Yes. The pack is updated every month for as long as the exam is live, and updates are free for everyone who has bought it.

What if I fail the exam?

We refund the pack, or swap it for any other pack if you would rather keep studying. Sit the exam 7 to 30 days after buying, then send your official score report within 7 days of the exam date, as set out in the refund policy.

What is your pass rate?

99% of customers who prepare with a CertStash pack pass. If you do not, we refund the pack, or swap it for another pack.

Can I share it with colleagues?

Each purchase is licensed to one person. For a team, school or training organisation, email support@certstash.com for a licence that fits.

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