Oracle 1z0-819 Exam Dumps

Which set of commands is necessary to create and run a custom runtime image from Java source files? 

A. java, jdeps
B. javac, jlink
C. jar, jlink
D. javac, jar

Answer: B

Which statement about a functional interface is true? 

A. It must be defined with the public access modifier.
B. It must be annotated with @FunctionalInterface.
C. It is declared with a single abstract method.
D. It is declared with a single default method.
E. It cannot have any private methods and static methods.

Answer: C

Which two statements are true about the modular JDK? (Choose two.) 

A. The foundational APIs of the Java SE Platform are found in the java.base module.
B. An application must be structured as modules in order to run on the modular JDK.
C. It is possible but undesirable to configure modules’ exports from the command line.
D. APIs are deprecated more aggressively because the JDK has been modularized.

Answer: A,C

Which two statements are true about Java modules? (Choose two.) 

A. Modular jars loaded from --module-path are automatic modules.
B. Any named module can directly access all classes in an automatic module.
C. Classes found in –classpath are part of an unnamed module.
D. Modular jars loaded from –classpath are automatic modules.
E. If a package is defined in both the named module and the unnamed module, then thepackage in the unnamed module is ignored.

Answer: A,C

Which is the correct order of possible statements in the structure of a Java class file? 

A. class, package, import
B. package, import, class
C. import, package, class
D. package, class, import
E. import, class, package

Answer: B

Which two are successful examples of autoboxing? (Choose two.) 

A. String a = “A”;
B. Integer e = 5;
C. Float g = Float.valueOf(null);
D. Double d = 4;
E. Long c = 23L;
F. Float f = 6.0;

Answer: A,B

Which three annotation uses are valid? (Choose three.) 

A. Function func = (@NonNull x) > x.toUpperCase();  
B. var v = “Hello” + (@Interned) “World”
C. Function<String, String> func = (var @NonNull x) > x.toUpperCase();
D. Function<String, String> func = (@NonNull var x) > x.toUpperCase();
E. var myString = (@NonNull String) str;
F. var obj = new @Interned MyObject();

Answer: A,C,F?

Which interface in the java.util.function package will return a void return type? 

A. Supplier
B. Predicate
C. Function
D. Consumer

Answer: D

Given the code fragment:var pool = Executors.newFixedThreadPool(5);Future outcome = pool.submit(() > 1);Which type of lambda expression is passed into submit()?

A. java.lang.Runnable
B. java.util.function.Predicate
C. java.util.function.Function
D. java.util.concurrent.Callable
Answer: D

Answer: D

Given:var fruits = List.of(“apple”, “orange”, “banana”, “lemon”);You want to examine the first element that contains the character n. Which statement willaccomplish this?

A. String result = fruits.stream().filter(f > f.contains(“n”)).findAny();
B. fruits.stream().filter(f > f.contains(“n”)).forEachOrdered(System.out::print);
C. Optional<String> result = fruits.stream().filter(f > f.contains (“n”)).findFirst ();
D. Optional<String> result = fruits.stream().anyMatch(f > f.contains(“n”));

Answer: B

Which statement about access modifiers is correct? 

A. An instance variable can be declared with the static modifier.
B. A local variable can be declared with the final modifier.
C. An abstract method can be declared with the private modifier.
D. An inner class cannot be declared with the public modifier.
E. An interface can be declared with the protected modifier.

Answer: B

Which code is correct? 

A. Runnable r = “Message” > System.out.println();
B. Runnable r = () > System.out::print;
C. Runnable r = () -> {System.out.println(“Message”);};
D. Runnable r = > System.out.println(“Message”);
E. Runnable r = {System.out.println(“Message”)};

Answer: C

Which two statements independently compile? (Choose two.) 

A. List<? super Short> list = new ArrayList<Number>();
B. List<? super Number> list = new ArrayList<Integer>();
C. List<? extends Number> list = new ArrayList<Byte>();
D. List<? extends Number> list = new ArrayList<Object>();
E. List<? super Float> list = new ArrayList<Double>();

Answer: A,C

Which two statements set the default locale used for formatting numbers, currency, and percentages? (Choose two.)

A. Locale.setDefault(Locale.Category.FORMAT, “zh-CN”);
B. Locale.setDefault(Locale.Category.FORMAT, Locale.CANADA_FRENCH);
C. Locale.setDefault(Locale.SIMPLIFIED_CHINESE);
D. Locale.setDefault(“en_CA”);
E. Locale.setDefault(“es”, Locale.US);

Answer: B,D

Given the Person class with age and name along with getter and setter methods, and this code fragment:What will be the result?

A. Aman Tom Peter
B. Tom Aman Peter
C. Aman Peter Tom
D. Tom Peter Aman

Answer: C

Given:List<String> list1 = new ArrayList<>();list1.add(“A”);list1.add(“B”);List list2 = List.copyOf(list1);list2.add(“C”);List<List<String>> list3 = List.of(list1, list2);System.out.println(list3);What is the result?

A. [[A, B],[A, B]]
B. An exception is thrown at run time.
C. [[A, B], [A, B, C]]
D. [[A, B, C], [A, B, C]]

Answer: B

Which two commands are used to identify class and module dependencies? (Choose two.) 

A. jmod describe
B. java Hello.java
C. jdeps --list-deps
D. jar --show-module-resolution
E. java --show-module-resolution

Answer: C,E

Given:public class X {}andpublic final class Y extends X {}What is the result of compiling these two classes?

A. The compilation fails because there is no zero args constructor defined in class X.
B. The compilation fails because either class X or class Y needs to implement the toString() method.
C. The compilation fails because a final class cannot extend another class.
D. The compilation succeeds.

Answer: B