OpenExamsFREE PRACTICE — ANY EXAM

Oracle Certified Professional: Java SE 21 Developer — Requirements & Free Practice

US · License preparation

200 free questions · Answer explanations · No signup required

Loading selected examination banks…

Choose what to practice

Start with an exam below. Your examination requirements depend on your application pathway. View licensing requirements

Licenses, application pathways and examination requirements

Each license and applicant pathway has its own requirements and exemptions. Choosing practice questions does not determine your eligibility.

Oracle Certified Professional: Java SE 21 Developer

Oracle professional certification validating Java Standard Edition 21 development skills, earned by passing the Java SE 21 Developer Professional examination (1Z0-830).

Licensing authority: Oracle · Application information

Initial by examination
Java SE 21 Developer Professional
Check In
Use a suitable personal desktop/laptop, reliable internet, microphone and webcam; government ID must match registration names, with two acceptable IDs available if requested; check in 30 minutes early in a quiet private room under the published device and material restrictions.
Credential Requirement
Register, attend and pass 1Z0-830 for the associated Java SE 21 Developer professional credential.
Dates
Official credential, route and current content start/end dates are not stated; unknown dates remain null. Retrieval and announcement dates were not substituted for effective dates.
Delivery And Seat Conditions
Register online using an Oracle account and a purchased exam attempt within its subscription period; actual appointments are subject to availability. The catalogue states six months to take the exam. No seat or institution-arranged delivery is promised for a specific date in the requested 2026-11-25 to 2027-02-28 horizon.
General Program Policies
Oracle export restrictions, candidate agreement and program rules apply; the source guidelines preserve case-by-case exceptions. A passed exam cannot be retaken.
Learning Path Access
The downloaded learning-path DOM contains a Learning Path Completion Required dialog with an 80% completion message, but its oj-dialog has style=display: none; this untriggered interface template does not establish a mandatory applicant qualification and does not override the exam-specific optional-training statement.
Reschedule And Cancellation
Changes or cancellation require at least 24 hours before the appointment; late cancellation risks forfeiting the exam attempt.
Training
The exam-specific page explicitly calls recommended training optional; no earlier Java certification examination is named as a prerequisite in the obtained exam or route materials.

Java SE 21 Developer Professional

Provider
Oracle University
Format
Proctored Online; Multiple Choice
Exam questions
Total questions: 50.
Time limit
120 Minutes
Passing score
68%
Examination outline
  • Handling Date, Time, Text, Numeric and Boolean Values
    • Primitives, wrappers, expressions, Math API and conversions
    • Text, text blocks, String and StringBuilder
    • Date-Time API, zones and daylight saving time
  • Controlling Program Flow
    • Conditional, switch and loop constructs; break and continue
  • Using Object-Oriented Concepts in Java
    • Objects, nested classes, references and garbage collection
    • Classes, records, fields, methods, constructors and initializers
    • Method overloading and variable arguments
    • Variable scope, encapsulation, immutability and local type inference
    • Inheritance, sealed types, polymorphism, casting and pattern matching
    • Interfaces, functional interfaces and interface methods
    • Enums with fields, methods and constructors
  • Handling Exceptions
    • Try/catch/finally, resources, multi-catch and custom exceptions
  • Working with Arrays and Collections
    • Arrays, List, Set, Map and Deque operations
  • Working with Streams and Lambda expressions
    • Object and primitive stream pipelines with functional interfaces
    • Decomposition, concatenation, reduction, grouping and partitioning
  • Packaging and Deploying Java Code
    • Modules, reflection, dependencies, services, providers and consumers
    • Compilation, JARs, runtime images and module migration
  • Managing Concurrent Code Execution
    • Platform and virtual threads, tasks, lifecycle and executors
    • Thread safety, locking and concurrent APIs
    • Concurrent collection processing and parallel streams
  • Using Java I/O API
    • Console and file I/O streams
    • Object serialization and deserialization
    • Path objects, properties and java.nio.file
  • Implementing Localization
    • Locales, resource bundles, message and value parsing and formatting
Examination sources