[UPDATED] Oracle 1Z0-829 Certification Exam Questions [Q18-Q35]

[UPDATED] Oracle 1Z0-829 Certification Exam Questions

Quickly and Easily Pass Oracle Exam with 1Z0-829 real Dumps

One of the key benefits of obtaining the Oracle 1Z0-829 certification is the validation of your skills and expertise in Java SE 17 development. Java SE 17 Developer certification is recognized globally and can help you to stand out in a competitive job market. It is also a valuable asset for those who are looking to advance their career within their current organization.

NEW QUESTION # 18
Which statement is true?

A. IllegalStateException is thrown if a thread in waiting state is moved back to runnable.
B. A thread in waiting state must handle InterrupedException.
C. thread in waiting state consumes CPU cycles.
D. After the timed wait expires, the waited thread moves to the terminated state.

Answer: B

Explanation:
A thread in waiting state is waiting for another thread to perform a particular action, such as calling notify() or notifyAll() on a shared object, or terminating a joined thread. A thread in waiting state can be interrupted by another thread, which will cause the waiting thread to throw an InterruptedException and return to the runnable state. Therefore, a thread in waiting state must handle InterruptedException, either by catching it or declaring it in the throws clause. Reference: Thread.State (Java SE 17 & JDK 17), [Thread (Java SE 17 & JDK 17)]

NEW QUESTION # 19
Given the code fragment:

Which action sorts the book list?

A. At Line n1, convert type to mutable array type.
B. At line n1, convert books type to mutable ArrayList type.
C. At Line n2, replace books,sort() with books.stream().sort(0.
D. At Line n2, replace compareTo () with compare ().

Answer: D

Explanation:
The code fragment is trying to sort a list of books using the Collections.sort() method. The correct answer is D, because the compareTo() method is not the correct way to compare two objects in a Comparator. The compare() method is the correct way to compare two objects in a Comparator and return an int value that indicates their order1. The compareTo() method is used to implement the Comparable interface, which defines the natural order of objects of a class2. The other options are incorrect because they either do not change the type of the list, which is already mutable, or they do not use the correct syntax for sorting a stream, which requires a terminal operation such as collect()3. Reference: Comparator (Java SE 17 & JDK 17), Comparable (Java SE 17 & JDK 17), Stream (Java SE 17 & JDK 17)

NEW QUESTION # 20
Given:

Which two should the module-info file include for it to represent the service provider interface?

A. Provides.com.transport.vehicle.cars.Car with com.transport.vehicle.cars. impt, CatImpI;
B. Exports com.transport.vehicle;
C. Requires cm.transport.vehicle,cars:
D. exports com.transport.vehicle.cars.Car;
E. Requires cm.transport.vehicle,cars:
F. Exports com.transport.vehicle.cars;
G. Provides.com.transport.vehicle.cars.Car impl,CarImp1 to com.transport.vehicle.cars. Cars

Answer: A,D

Explanation:
The answer is B and E because the module-info file should include a provides directive and an exports directive to represent the service provider interface. The provides directive declares that the module provides an implementation of a service interface, which is com.transport.vehicle.cars.Car in this case. The with clause specifies the fully qualified name of the service provider class, which is com.transport.vehicle.cars.impl.CarImpl in this case. The exports directive declares that the module exports a package, which is com.transport.vehicle.cars in this case, to make it available to other modules. The package contains the service interface that other modules can use.
Option A is incorrect because requires is not the correct keyword to declare a service provider interface. Requires declares that the module depends on another module, which is not the case here.
Option C is incorrect because it has a typo in the module name. It should be com.transport.vehicle.cars, not cm.transport.vehicle.cars.
Option D is incorrect because it has a typo in the keyword provides. It should be provides, not Provides. It also has a typo in the service interface name. It should be com.transport.vehicle.cars.Car, not com.transport.vehicle.cars.Car impl. It also has an unnecessary to clause, which is used to limit the accessibility of an exported package to specific modules.
Option F is incorrect because it exports the wrong package. It should export com.transport.vehicle.cars, not com.transport.vehicle.cars.impl. The impl package contains the service provider class, which should not be exposed to other modules.
Option G is incorrect because it exports the wrong package. It should export com.transport.vehicle.cars, not com.transport.vehicle. The vehicle package does not contain the service interface or the service provider class. Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
Java Modules - Service Interface Module - GeeksforGeeks
Java Service Provider Interface | Baeldung

NEW QUESTION # 21
Given the code fragment:

What is the result?

A. Logged out at: 2021-01-12T21:58:00z
B. Can't logout
C. Logged out at: 2021-0112T21:58:19.880z
D. A compilation error occurs at Line n1.

Answer: A

Explanation:
Explanation
The code fragment is using the Java SE 17 API to get the current time and then truncating it to minutes. The result will be the current time truncated to minutes, which is why option B is correct. References:
https://education.oracle.com/products/trackp_OCPJSE17
https://mylearn.oracle.com/ou/learning-path/java-se-17-developer/99487
https://docs.oracle.com/javase/17/docs/api/java.base/java/time/Instant.html#truncatedTo(java.time.tempora

NEW QUESTION # 22
Given the code fragment:

abstract sealed interface SInt permits Story, Art { default String getTitle() { return "Book Title" ; }
}
Which set of class definitions compiles?

A. Non-sealed interface story extends SInt {}
Non-sealed interaface Art extends Sint {}
B. Sealed interface Storty extends sInt {}
Non-sealed class Art implements Sint {}
C. Non-sealed interface story extends SInt {}
Class Art implements Sint {}
D. Interace story extends STnt {}
Interface Art extends SInt {}
E. Public interface story extends sInd {}
Public interface Art extends SInt {}

Answer: B

Explanation:
The answer is C because the code fragment given is an abstract sealed interface SInt that permits Story and Art. The correct answer is option C, which is a sealed interface Story that extends SInt and a non-sealed class Art that implements SInt. This is because a sealed interface can only be extended by the classes or interfaces that it permits, and a non-sealed class can implement a sealed interface.
Option A is incorrect because interface is misspelled as interace, and Story and Art should be capitalized as they are the names of the permitted classes or interfaces.
Option B is incorrect because public is misspelled as public, and sInd should be SInt as it is the name of the sealed interface.
Option D is incorrect because a non-sealed interface cannot extend a sealed interface, as it would violate the restriction of permitted subtypes.
Option E is incorrect because both Story and Art cannot be non-sealed interfaces, as they would also violate the restriction of permitted subtypes.
Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
Sealed Classes and Interfaces in Java 15 | Baeldung
Sealed Class in Java - Javatpoint

NEW QUESTION # 23
Which statement is true about migration?

A. Every module is moved to the module path in a top-down migration.
B. The required modules migrate before the modules that depend on them in a top-down ^migration.
C. Every module is moved to the module path in a bottom-up migration.
D. Unnamed modules are automatic modules in a top-down migration.

Answer: C

Explanation:
The answer is B because a bottom-up migration is a strategy for modularizing an existing application by moving its dependencies to the module path one by one, starting from the lowest-level libraries and ending with the application itself. This way, each module can declare its dependencies on other modules using the module-info.java file, and benefit from the features of the Java Platform Module System (JPMS), such as reliable configuration, strong encapsulation, and service loading.
Option A is incorrect because a top-down migration is a strategy for modularizing an existing application by moving it to the module path first, along with its dependencies as automatic modules. Automatic modules are non-modular JAR files that are treated as modules with some limitations, such as not having a module descriptor or a fixed name. A top-down migration allows the application to use the module path without requiring all of its dependencies to be modularized first.
Option C is incorrect because a top-down migration does not require any specific order of migrating modules, as long as the application is moved first and its dependencies are moved as automatic modules. A bottom-up migration, on the other hand, requires the required modules to migrate before the modules that depend on them.
Option D is incorrect because unnamed modules are not automatic modules in any migration strategy. Unnamed modules are modules that do not have a name or a module descriptor, such as classes loaded from the class path or dynamically generated classes. Unnamed modules have unrestricted access to all other modules, but they cannot be accessed by named modules, except through reflection with reduced security checks. Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
Migrating to Modules (How and When) - JavaDeploy
Java 9 Modularity: Patterns and Practices for Developing Maintainable Applications

NEW QUESTION # 24
Given:

Which two modifications enable the code to print Open Close?

Answer: D,E

Explanation:
The code given is a try-with-resources statement that declares a resource of type AutoCloseable. The resource is an anonymous class that implements the AutoCloseable interface and overrides the close() method. The code also has a print() method that prints the value of the variable s. The code is supposed to print "Open Close", but it does not compile because of two errors.
The first error is at line n1, where the anonymous class is missing a semicolon at the end of its declaration. This causes a syntax error and prevents the code from compiling. To fix this error, option B adds a semicolon after the closing curly brace of the anonymous class.
The second error is at line n2, where the print() method is called without an object reference. This causes a compilation error because the print() method is not static and cannot be invoked without an object. To fix this error, option E adds an object reference to the print() method by using the variable t.
Therefore, options B and E are correct and enable the code to print "Open Close".

NEW QUESTION # 25
Given:

What is the result?

A. UserName
B. User name (US)
C. User name (EN - US)
D. User name (EN)
E. The program throws a MissingResourceException.

Answer: E

Explanation:
The answer is B because the code fragment contains a logical error that causes a MissingResourceException at runtime. The code fragment tries to load a resource bundle with the base name "Captions.properties" and the locale "en_US". However, there is no such resource bundle available in the classpath. The available resource bundles are:
Captions.properties
Captions_en.properties
Captions_US.properties
Captions_en_US.properties
The ResourceBundle class follows a fallback mechanism to find the best matching resource bundle for a given locale. It first tries to find the resource bundle with the exact locale, then it tries to find the resource bundle with the same language and script, then it tries to find the resource bundle with the same language, and finally it tries to find the default resource bundle with no locale. If none of these resource bundles are found, it throws a MissingResourceException.
In this case, the code fragment is looking for a resource bundle with the base name "Captions.properties" and the locale "en_US". The ResourceBundle class will try to find the following resource bundles in order:
Captions.properties_en_US
Captions.properties_en
Captions.properties
However, none of these resource bundles exist in the classpath. Therefore, the ResourceBundle class will throw a MissingResourceException.
To fix this error, the code fragment should use the correct base name of the resource bundle family, which is "Captions" without the ".properties" extension. For example:
ResourceBundle captions = ResourceBundle.getBundle("Captions", currentLocale); This will load the appropriate resource bundle for the current locale, which is "Captions_en_US.properties" in this case. Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
ResourceBundle (Java Platform SE 8 )
About the ResourceBundle Class (The Java™ Tutorials > Internationalization)

NEW QUESTION # 26
Given the content of the in. tart file:
23456789
and the code fragment:

What is the content of the out .txt file?

A. 0123456789234567
B. 012345678901234
C. 012345678
D. 0123456789
E. 01234567
F. 01234567801234

Answer: D

Explanation:
The answer is D because the code fragment reads the content of the in.txt file and writes it to the out.txt file. The content of the in.txt file is "23456789". The code fragment uses a char array buffer of size 8 to read the content of the in.txt file. The while loop reads the content of the in.txt file and writes it to the out.txt file until the end of the file is reached. Therefore, the content of the out.txt file will be "0123456789".

NEW QUESTION # 27
Given:

and the code fragment:

A. 100.00
CellPhone,ToyCar,Motor,Fan
B. 100.00 CellPhone,ToyCar
C. 300.00
CellPhone.ToyCar
D. 300.00
CellPhone,ToyCar,Motor,Fan

Answer: D

Explanation:
The code fragment is using the Stream API to perform a reduction operation on a list of ElectricProduct objects. The reduction operation consists of three parts: an identity value, an accumulator function, and a combiner function. The identity value is the initial value of the result, which is 0.0 in this case. The accumulator function is a BiFunction that takes two arguments: the current result and the current element of the stream, and returns a new result. In this case, the accumulator function is (a,b) -> a + b.getPrice (), which means that it adds the price of each element to the current result. The combiner function is a BinaryOperator that takes two partial results and combines them into one. In this case, the combiner function is (a,b) -> a + b, which means that it adds the two partial results together.
The code fragment then applies a filter operation on the stream, which returns a new stream that contains only the elements that match the given predicate. The predicate is p -> p.getPrice () > 10, which means that it selects only the elements that have a price greater than 10. The code fragment then applies a map operation on the filtered stream, which returns a new stream that contains the results of applying the given function to each element. The function is p -> p.getName (), which means that it returns the name of each element.
The code fragment then calls the collect method on the mapped stream, which performs a mutable reduction operation on the elements of the stream using a Collector. The Collector is Collectors.joining (","), which means that it concatenates the elements of the stream into a single String, separated by commas.
The code fragment then prints out the result of the reduction operation and the result of the collect operation, separated by a new line. The result of the reduction operation is 300.00, which is the sum of the prices of all ElectricProduct objects that have a price greater than 10. The result of the collect operation is CellPhone,ToyCar,Motor,Fan, which is the concatenation of the names of all ElectricProduct objects that have a price greater than 10.
Therefore, the output of the code fragment is:
300.00 CellPhone,ToyCar,Motor,Fan

NEW QUESTION # 28
Which two code fragments compile?

Answer: A,E

Explanation:
Explanation
The two code fragments that compile are B and E. These are the only ones that use the correct syntax for declaring and initializing a var variable. The var keyword is a reserved type name that allows the compiler to infer the type of the variable based on the initializer expression. However, the var variable must have an initializer, and the initializer must not be null or a lambda expression. Therefore, option A is invalid because it does not have an initializer, option C is invalid because it has a null initializer, and option D is invalid because it has a lambda expression as an initializer. Option B is valid because it has a String initializer, and option E is valid because it has an int initializer.
https://docs.oracle.com/en/java/javase/17/language/local-variable-type-inference.html

NEW QUESTION # 29
Daylight Saving Time (DST) is the practice of advancing clocks at the start of spring by one hour and adjusting them backward by one hour in autumn.
Considering that in 2021, DST in Chicago (Illinois) ended on November 7th at 2 AM, and given the fragment:

What is the output?

A. false
true
B. False
false
C. true
true
D. true
false

Answer: D

Explanation:
The answer is A because the code fragment uses the ZoneId and ZonedDateTime classes to create two date-time objects with the same local date-time but different zone offsets. The ZoneId class represents a time-zone ID, such as America/Chicago, and the ZonedDateTime class represents a date-time with a time-zone in the ISO-8601 calendar system. The code fragment creates two ZonedDateTime objects with the same local date-time of 2021-11-07T01:30, but different zone IDs of America/Chicago and UTC. The code fragment then compares the two objects using the equals and isEqual methods.
The equals method compares the state of two objects for equality. In this case, it compares the local date-time, zone offset, and zone ID of the two ZonedDateTime objects. Since the zone offsets and zone IDs are different, the equals method returns false.
The isEqual method compares the instant of two temporal objects for equality. In this case, it compares the instant of the two ZonedDateTime objects, which is derived from the local date-time and zone offset. Since DST in Chicago ended on November 7th at 2 AM in 2021, the local date-time of 2021-11-07T01:30 in America/Chicago corresponds to the same instant as 2021-11-07T06:30 in UTC. Therefore, the isEqual method returns true.
Hence, the output is true false. Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
ZoneId (Java Platform SE 8 )
ZonedDateTime (Java Platform SE 8 )
Time Zone & Clock Changes in Chicago, Illinois, USA
Daylight Saving Time Changes 2023 in Chicago, USA

NEW QUESTION # 30
Given:

What is the result

A. Marketing
B. Marketing
Undefined
C. UnDefined
D. Marketing
Finance
Technical

Answer: C

Explanation:
Explanation
The code fragment is using the switch statement with the new Java 17 syntax. The switch statement checks the value of the variable desig and executes the corresponding case statement. In this case, the value of desig is
"CTO", which does not match any of the case labels. Therefore, the default case statement is executed, which prints "Undefined". The other case statements are not executed, because there is no fall through in the new syntax. Therefore, the output of the code fragment is:
Undefined

NEW QUESTION # 31
Given the product class:

And the shop class:

What is the result?

A. Cookie 2.99 2.99
B. Cookie 0.0 2.99
C. Cookie 0.0 0.0
D. Cookie 3.99 2.99
E. Compilation fails
F. An exception is produced at runtime

Answer: E

Explanation:
The code fragment will fail to compile because the readObject method in the Product class is missing the @Override annotation. The readObject method is a special method that is used to customize the deserialization process of an object. It must be declared as private, have no return type, and take a single parameter of type ObjectInputStream. It must also be annotated with @Override to indicate that it overrides the default behavior of the ObjectInputStream class. Without the @Override annotation, the compiler will treat the readObject method as a normal method and not as a deserialization hook. Therefore, the code fragment will produce a compilation error. Reference: Object Serialization - Oracle, [ObjectInputStream (Java SE 17 & JDK 17) - Oracle]

NEW QUESTION # 32
Given the code fragment:

What is the result?

A. false 1
false 2
B. false 1
ture 2
C. falase 0
true 1
D. true 1
false 2

Answer: C

Explanation:
The code fragment is comparing the values of a, b, and c using the < and > operators. The first comparison, d, is checking if a is less than b and greater than c. Since a is equal to 2, b is equal to -2, and c is equal to -4, this comparison will evaluate to true. The second comparison, e, is checking if a is greater than b and a is greater than c. Since a is equal to 2, b is equal to -2, and c is equal to -4, this comparison will evaluate to false. Therefore, the result will be true 1 false 2. Reference: Operators (The Java™ Tutorials > Learning the Java Language - Oracle

NEW QUESTION # 33
Given:

What is the result?

A. Software Game read error
B. Software Game Chess 0
C. Software Game Chess 2
D. Software Game Software Game chess 0
E. Software Game Software Game Chese 2
F. Software game write error

Answer: E

Explanation:
The answer is B because the code uses the writeObject and readObject methods of the ObjectOutputStream and ObjectInputStream classes to serialize and deserialize the Game object. These methods use the default serialization mechanism, which writes and reads the state of the object's fields, including the inherited ones. Therefore, the title field of the Software class is also serialized and deserialized along with the players field of the Game class. The toString method of the Game class calls the toString method of the Software class using super.toString(), which returns the value of the title field. Hence, when the deserialized object is printed, it shows "Software Game Software Game Chess 2". Reference:
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
Serialization and Deserialization in Java with Example

NEW QUESTION # 34
Given:

What is the result?

A. B A C
B. D A D
C. B A D
D. D D D

Answer: C

Explanation:
Explanation
The answer is C because the code demonstrates the concept of method overloading and type conversion in Java. Method overloading allows different methods to have the same name but different parameters. Type conversion allows values of one data type to be assigned to another data type, either automatically or explicitly. In the code, the class Test has four methods named sum, each with different parameter types: int, float, and double. The main method creates an instance of Test and calls the sum method with different arguments. The compiler will choose the most specific method that matches the arguments, based on the following rules:
If there is an exact match between the argument types and the parameter types, that method is chosen.
If there is no exact match, but there is a method with compatible parameter types, that method is chosen.
Compatible types are those that can be converted from one to another automatically, such as int to long or float to double.
If there is more than one method with compatible parameter types, the most specific method is chosen.
The most specific method is the one whose parameter types are closest to the argument types in terms of size or precision.
In the code, the following method calls are made:
test.sum(10, 10.5) -> This matches the sum(int a, float b) method exactly, so it is chosen.
The result is 20.5, which is converted to int and printed as 20 (B).
test.sum(10) -> This does not match any method exactly, but it matches the sum(double a) method with compatible types, as int can be converted to double automatically. The result is 10.0, which is printed as 10
(A). test.sum(10.5, 10) -> This does not match any method exactly, but it matches two methods with compatible types: sum(float a, float b) and sum(double a, double b). The latter is more specific, as double is closer to the argument types than float. The result is 20.5, which is printed as 20 (D).
Therefore, the output is B A D. References
Oracle Certified Professional: Java SE 17 Developer
Java SE 17 Developer
OCP Oracle Certified Professional Java SE 17 Developer Study Guide
Method Overloading in Java
Type conversion in Java with Examples
Java Method Overloading with automatic type conversions