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Oracle 1z0-830 Exam Syllabus Topics:
| Section | Weight | Objectives |
|---|---|---|
| Java I/O and Localization | 5% | - File I/O, NIO.2, streams, readers/writers, serialization - Resource bundles, locale, formatting messages, numbers, dates |
| Handling Exceptions | 8% | - Exception hierarchy, try-catch-finally, multi-catch, try-with-resources - Create and use custom exceptions, throw, throws |
| Concurrency and Multithreading | 10% | - Synchronization, locks, concurrent collections, thread safety - Thread lifecycle, Runnable, Callable, ExecutorService, virtual threads |
| Controlling Program Flow | 10% | - Decision constructs: if-else, switch expressions and statements, pattern matching - Loops: for, enhanced for, while, do-while, break, continue, return |
| Functional Programming and Streams | 15% | - Optional class, primitive streams - Lambda expressions, functional interfaces, method references - Stream API: create, intermediate/terminal operations, parallel streams, grouping, partitioning |
| Using Object-Oriented Concepts | 20% | - Overloading, overriding, Object class methods, immutable objects - Enums, nested classes, local variable type inference - Classes, records, objects, constructors, initializers, methods, fields, encapsulation - Inheritance, abstract classes, sealed classes, interfaces, polymorphism |
| Handling Date, Time, Text, Numeric and Boolean Values | 12% | - Use primitives and wrapper classes, evaluate expressions and apply type conversions - Use Date-Time API: LocalDate, LocalTime, LocalDateTime, Period, Duration, Instant, ZonedDateTime - Manipulate text, text blocks, String, StringBuilder and StringBuffer |
| Advanced Features and Annotations | 3% | - Annotations, built-in annotations, custom annotations - Generics, type parameters, wildcards, type erasure |
| Modules and Packaging | 5% | - Module system: module-info.java, exports, requires, provides, uses - Create and use JAR files, modular and non-modular builds |
| Working with Arrays and Collections | 12% | - Declare, instantiate, initialize, use arrays and multidimensional arrays - Collections Framework: List, Set, Map, Deque, Queue, sorting, searching |
Oracle Java SE 21 Developer Professional Sample Questions:
1. You are working on a module named perfumery.shop that depends on another module named perfumery.
provider.
The perfumery.shop module should also make its package perfumery.shop.eaudeparfum available to other modules.
Which of the following is the correct file to declare the perfumery.shop module?
A) File name: module-info.perfumery.shop.java
java
module perfumery.shop {
requires perfumery.provider;
exports perfumery.shop.eaudeparfum.*;
}
B) File name: module.java
java
module shop.perfumery {
requires perfumery.provider;
exports perfumery.shop.eaudeparfum;
}
C) File name: module-info.java
java
module perfumery.shop {
requires perfumery.provider;
exports perfumery.shop.eaudeparfum;
}
2. Given:
java
ExecutorService service = Executors.newFixedThreadPool(2);
Runnable task = () -> System.out.println("Task is complete");
service.submit(task);
service.shutdown();
service.submit(task);
What happens when executing the given code fragment?
A) It exits normally without printing anything to the console.
B) It prints "Task is complete" once, then exits normally.
C) It prints "Task is complete" twice and throws an exception.
D) It prints "Task is complete" once and throws an exception.
E) It prints "Task is complete" twice, then exits normally.
3. Given a properties file on the classpath named Person.properties with the content:
ini
name=James
And:
java
public class Person extends ListResourceBundle {
protected Object[][] getContents() {
return new Object[][]{
{"name", "Jeanne"}
};
}
}
And:
java
public class Test {
public static void main(String[] args) {
ResourceBundle bundle = ResourceBundle.getBundle("Person");
String name = bundle.getString("name");
System.out.println(name);
}
}
What is the given program's output?
A) James
B) Compilation fails
C) Jeanne
D) MissingResourceException
E) JeanneJames
F) JamesJeanne
4. Given:
java
public static void main(String[] args) {
try {
throw new IOException();
} catch (IOException e) {
throw new RuntimeException();
} finally {
throw new ArithmeticException();
}
}
What is the output?
A) RuntimeException
B) ArithmeticException
C) Compilation fails
D) IOException
5. Given:
java
String s = " ";
System.out.print("[" + s.strip());
s = " hello ";
System.out.print("," + s.strip());
s = "h i ";
System.out.print("," + s.strip() + "]");
What is printed?
A) [ , hello ,hi ]
B) [,hello,h i]
C) [ ,hello,h i]
D) [,hello,hi]
Solutions:
| Question # 1 Answer: C | Question # 2 Answer: D | Question # 3 Answer: C | Question # 4 Answer: B | Question # 5 Answer: B |

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