1z0-819 Java SE 11 Developer Questions and Answers

Function function = String::toUpperCase;

UnaryOperator function = s −> s.toUpperCase();

UnaryOperator function = String::toUpperCase;

Function function = m −> m.toUpperCase();

protected void walk(){}

void walk(){}

abstract void walk();

private void walk(){}

public abstract void walk();

MyInterface1

MyInterface3

MyInterface5

MyInterface2

MyInterface4

Dr. Who

Dr. Null

An exception is thrown at runtime.

null

MessageBundle_en_US.properties

MessageBundle_en.properties

MessageBundle_fr_FR.properties

MessageBundle_US.properties

MessageBundle.properties

Map: 0 Keys: 0 Values: 0

The compilation fails.

Map: 4 Keys: 4 Values: 4

Map: 4 Keys: 0 Values: 0

Map: 0 Keys: 4 Values: 4

null

nothing

It fails to compile.

java.lang.IllegalAccessException is thrown.

Student

Input: Echo:

Input: Helloworld Echo: Helloworld

Input:

Then block until any input comes from System.in.

Input:

Echo: Helloworld

A NullPointerException is thrown at run time.

Insert PriceChecker (?) prod on line 1.

Insert PriceChecker <> prod on line 1.

Insert PriceChecker prod on line 1.

Insert PriceChecker prod on line 1.

Option A

Option B

Option C

Option D

5 4 3 2 1

5

nothing

5 4 3 2 1 4 3 2 1 3 2 1 2 1 1

Aman Tom Peter

Tom Aman Peter

Aman Peter Tom

Tom Peter Aman

Option A

Option B

Option C

Option D

getTCount

getACount

getTotalCount

getCCount

getGCount

Setting up the Java development environment requires that you also install the JRE.

The Java development environment is set up for all operating systems by default.

You set up the Java development environment for a specific operating system when you install the JDK.

Setting up the Java development environment occurs when you install an IDE before the JDK.

jdeps lists the module dependencies and the package names of all referenced JDK internal APIs. If any are found, the suggested replacements are output in the console.

jdeps outputs an error message that the -jdkinternals option requires either the -summary or the - verbose options to output to the console.

The -jdkinternals option analyzes all classes in the .jar and prints all class-level dependencies.

The -jdkinternals option analyzes all classes in the .jar for class-level dependencies on JDK internal APIs. If any are found, the results with suggested replacements are output in the console.

ab cd ef

An ArrayIndexOutOfBoundsException is thrown at runtime.

The compilation fails.

abc def

ad be cf

Joe

null

null

Mary

Joe

Marry

null

null

Function func = (@NonNull x) −> x.toUpperCase();

var v = “Hello” + (@Interned) “World”

Function func = (var @NonNull x) −> x.toUpperCase();

Function func = (@NonNull var x) −> x.toUpperCase();

var myString = (@NonNull String) str;

var obj = new @Interned MyObject();

You accept the change because -noverify is necessary for your code to run with the latest version of Java.

You reject the change because -Xms8g -Xmx8g uses too much system memory.

You accept the change because -noverify is a standard option that has been supported since Java 1.0.

You reject the change because -noverify is a critical security risk.

2

3

4

5

ToDoubleFunction

Supplier

BiFunction

LongConsumer

A module providing an implementation of country.CountryDetails can be compiled and added without recompiling the main module.

A module providing an implementation of country.CountryDetails must have a requires main; directive in its module-info.java file.

An implementation of country.countryDetails can be added to the main module.

To compile without an error, the application must have at least one module in the module source path that provides an implementation of country.CountryDetails.

To run without an error, the application must have at least one module in the module path that provides an implementation of country.CountryDetails.

public abstract void methodB();

final void methodG(){System.out.println(“G”);}

private abstract void methodC();

public String methodD();

public int x;

final void methodE();

public void methodF(){System.out.println(“F”);}

Create a method that validates the hostName and portNumber parameters before opening the socket.

Make enableService private.

Enclose the call to new Socket In an AccessController.doPrivileged block.

to process the current item and return void

to remove an item from the end of the stream

to process the current item and return a stream

to remove an item from the beginning of the stream

A java.util.NoSuchElementException is thrown at run time.

Ans : a

The compilation fails.

Ans :

null

Joe Bloggs

The compilation fails due to an error in line 1.

p1

Paths.get("foo")

Paths.getPath("too")

Path.get(new URI("file:///domains/oracle/test.txt"))

new Path("foo")

Paths.get(URL.create("file:///domains/oracle/test.txt"))

Character

char

String[ ]

String

java.base exports all of the Java platforms core packages.

module-info.java can be placed in any folder inside module-path.

A module must be declared in module-info.java file.

module-info.java cannot be empty.

By default, modules can access each other as long as they run in the same folder.

The compilation fails.

1) one2) two3) three

A java.lang.ArrayIndexOutOfBoundsException is thrown.

1) one

nothing

var lines = Files.lines(Paths.get(INPUT_FILE_NAME));

Stream lines = Files.readAllLines(Paths.get(INPUT_FILE_NAME));

var lines = Files.readAllLines(Paths.get(INPUT_FILE_NAME));

Stream lines = Files.lines(INPUT_FILE_NAME);

the loop starting line 11

the loop starting line 7

the loop starting line 14

the loop starting line 3

An indexOutofBoundsException is thrown at runtime.

At once 0

Hat at store 4

At once 1

Hat at store 1