Oracle Java SE 21 Developer Professional: 1Z0-830 (Udemy.com)
Preparation for Oracle Certification (Java Certification) Java SE 21 1Z0-830 with examples, quizes and home tasks
Created by: Andrii Piatakha
Last updated February 2026
What you will learn
- Master handling primitives, wrapper classes, and type conversions in Java
- Evaluate and apply arithmetic and boolean expressions with precedence rules
- Effectively manipulate text using String, StringBuilder, and text blocks
- Work with Java Date-Time API to handle date, time, period, and timezone objects
- Create and manage control flow constructs like if/else, switch, and loops
- Implement advanced object-oriented concepts, including encapsulation and inheritance
- Create classes, records, and instantiate fields, methods, and constructors
- Apply polymorphism, method overriding, and the instanceof operator with pattern matching
- Work with Java interfaces, functional methods, and enums effectively
- Handle exceptions using try/catch/finally, try-with-resources, and multi-catch blocks
- Create and manipulate arrays and Java Collections like List, Set, Map, and Deque
How it compares
Against the other 518 rated Udemy courses in Software Development on CourseDuck:
- Rating4.5 out of 5higher than 41% of them
- Reviews386#256 of 519 by number of reviews
- Length39.7 hourslonger than 95% of them
- Last updatedFebruary 2026more recently than 63% of them
Course Description
What Is Oracle 1Z0-830 Certification?
The Oracle 1Z0-830 certification, also known as the Java SE 21 Developer Certification, is an advanced credential that validates your expertise in modern Java development. This certification is specifically designed for professionals who want to showcase their skills in Java SE 21 features, covering a wide range of programming concepts, from object-oriented principles to modular applications.
Benefits of Earning This Certification
Career Growth: Elevate your profile with a globally recognized certification.
Updated Knowledge: Stay ahead with expertise in Java SE 21, the latest long-term support version.
Credibility: Demonstrates a deep understanding of core and advanced Java programming concepts.
Real-World Applications: Gain skills that are highly relevant to modern enterprise applications.
How This Course Prepares You
This course is crafted to help you master every topic required for the Oracle 1Z0-830 certification. It includes lessons to build your understanding and quizzes to test your knowledge. By the end of the course, you’ll be well-prepared to tackle the certification exam with confidence.
Topics Covered in This Course
The Oracle 1Z0-830 certification requires proficiency across various domains of Java development.
Below is a breakdown of the topics:
1. Handling Date, Time, Text, Numeric, and Boolean Values
Use primitives and wrapper classes, evaluate arithmetic and boolean expressions, and apply precedence rules, type conversions, and casting.
Manipulate text using String, StringBuilder, and text blocks.
Work with date, time, duration, period, and time-zone objects, including daylight saving time, using the Date-Time API.
2. Controlling Program Flow
Create and manage control flow constructs such as if/else, switch statements and expressions, loops, and break/continue statements.
3. Using Object-Oriented Concepts in Java
Declare and instantiate objects, including nested classes, and explain object lifecycles.
Create classes, records, and define/instantiate instance and static fields, methods, constructors, and initializers.
Implement method overloading, including var-arg methods.
Understand variable scopes, apply encapsulation, and create immutable objects.
Use local variable type inference.
Implement inheritance, including abstract and sealed types, record classes, and overriding methods, including those of the Object class.
Use polymorphism, casting, and the instanceof operator with pattern matching and switch constructs.
Create and use interfaces with functional methods, and private, static, and default methods.
Work with enums including fields, methods, and constructors.
4. Handling Exceptions
Handle exceptions with try/catch/finally, try-with-resources, and multi-catch blocks.
Create and use custom exceptions.
5. Working with Arrays and Collections
Create and manipulate arrays, List, Set, Map, and Deque collections, including adding, removing, updating, retrieving, and sorting elements.
6. Working with Streams and Lambda Expressions
Use Java Streams, including lambda expressions implementing functional interfaces, to filter, transform, process, and sort data.
Perform decomposition, concatenation, reduction, grouping, and partitioning on sequential and parallel streams.
7. Packaging and Deploying Java Code
Define and expose module content, including by reflection, and declare module dependencies.
Compile Java code, create modular/non-modular JARs, runtime images, and implement migration to modules using unnamed/automatic modules.
8. Managing Concurrent Code Execution
Create platform and virtual threads using Runnable and Callable objects.
Manage thread lifecycles and use different ExecutorService implementations and concurrent APIs.
Develop thread-safe code with locking mechanisms and process Java collections concurrently with parallel streams.
9. Using Java I/O API
Read/write console and file data using I/O Streams.
Serialize and deserialize Java objects.
Work with Path objects and their properties using the java.nio.file API.
10. Implementing Localization
Implement localization using locales and resource bundles.
Parse and format messages, dates, times, and numbers, including currency and percentage values.
11. Additional Java Features
Understand the basics of the Java Logging API.
Use annotations like @Override, @FunctionalInterface, @Deprecated, @SuppressWarnings, and @SafeVarargs.
Comprehensive Scope of Certification
By completing this course, you will develop proficiency in:
Handling Date, Time, Text, Numeric, and Boolean Values
Controlling Program Flow
Object-Oriented Concepts in Java
Handling Exceptions
Arrays and Collections
Streams and Lambda Expressions
Packaging and Deploying Java Code
Managing Concurrent Code Execution
Java I/O API
Localization
Additional Java Features
This comprehensive preparation ensures you are fully equipped to pass the Oracle 1Z0-830 certification and advance your career in Java development. Let’s begin!
Instructor Details
- 4.5 Rating
386 Reviews
Andrii Piatakha
Andrii Piatakha is a highly experienced educator, entrepreneur, project manager and software engineer with over 10 years of teaching experience and a proven track record of empowering students worldwide to achieve their goals in IT. As the Founder and CEO of IT-Bulls, Andrii has dedicated his career to promoting engineering excellence and shaping the next generation of IT professionals.
=== What Sets Andrii Apart? ===
Unparalleled Expertise
Andrii's career spans over a decade, during which he has mentored thousands of students and professionals. His hands-on experience as a software engineer and business leader allows him to deliver courses that are both practical and impactful. Andrii specializes in teaching Java, software architecture, cybersecurity, project management, web and application development, and more.
Transformative Education
Through his highly popular course “Java from Zero to First Job”, Andrii has helped countless individuals with no prior programming experience secure their first jobs in IT. This course is renowned for its structured approach, real-world projects, and ability to prepare students for success in the shortest possible time.
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Reviews
By Felipe Cesar Stanzani Fonseca on 7/21/2026
Não prepara para a certificação. É um curso de Java, e só.
By Shubham Vishnu Bhujbal on 7/7/2026
It very good experience to watch our course.
By Brice-Boris BEDA on 4/30/2026
This course is a goldmine. I highly recommend it. Thanks Andrii !
By Rakhymzhan Kenzhegul on 10/3/2025
This is the best online training course I’ve ever seen. The explanations are excellent, and the inclusion of additional tools and materials makes the course incredibly useful. Thank you for dedicating your time and effort to teaching others!
By AHLAM ET-TAYEA on 7/11/2025
This course is great for beginners. It teaches the basics like variables, functions, and loops, and helps you create simple interactive websites. The lessons are easy to follow and include practice exercises
By Ubaldo Flor Ortega on 5/16/2025
Content is really good, examples are clear and concise, the course covers a lot of details and edge cases. Personally speaking, the amount of videos could result in students losing focus, especially if they are hands-on learning based. I appreciate the effort and dedication invested to make this course.
By Sukhrob Tokhirov on 3/9/2025
I think it is an amazing course and suggestions the teacher giving is top notch
By Udemy User on 2/24/2025
I want to get ready to pass my certification Java SE 21 .
By Anu Ikkurti on 2/4/2025
Pretty clear, concise, hitting on important aspects
By Rohit singh on 12/2/2024
This course is exceptionally well-structured and delivered with clarity. The instructor provides comprehensive explanations and practical insights, ensuring a thorough understanding of the subject. Highly recommended for anyone seeking to enhance their knowledge and skills in this area.
Quality Score
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Overall Score : 90 / 100









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