Java 21 (830) vs Java 17 (829)

It's often helpful to be able to map objectives between exams. The new exam removes JDBC, adds more pattern matching, virtual threads and a few changes in behavior.

Note: Oracle makes changes to the objectives. These objectives are as of when the 830 exam launched and may vary slightly from the latest. The gist is the same.

OCP 21 830 Objective	OCP 21 830 Text	Java 17 Objective and Comments
Handling Date, Time, Text, Numeric and Boolean Values
1.1	Use primitives and wrapper classes. Evaluate arithmetic and boolean expressions, using the Math API and by applying precedence rules, type conversions, and casting.	1.1, minor verbiage changes
1.2	Manipulate text, including text blocks, using String and StringBuilder classes.	1.2
1.3	Manipulate date, time, duration, period, instant and time-zone objects including daylight saving time using Date-Time API.	1.2,  didn't have daylight savings
Controlling Program Flow
2.1	Create program flow control constructs including if/else, switch statements and expressions, loops, and break and continue statements.	2.1
Using Object-Oriented Concepts in Java
3.1	Declare and instantiate Java objects including nested class objects, and explain the object life-cycle including creation, reassigning references, and garbage collection.	3.1
3.2	Create classes and records, and define and use instance and static fields and methods, constructors, and instance and static initializers.	3.2
3.3	Implement overloaded methods, including var-arg methods.	3.3, minor verbiage changes
3.4	Understand variable scopes, apply encapsulation, and create immutable objects. Use local variable type inference.	3.4
3.5	Implement inheritance, including abstract and sealed types as well as record classes. Override methods, including that of the Object class. Implement polymorphism and differentiate between object type and reference type. Perform reference type casting, identify object types using the instanceof operator, and pattern matching with the instanceof operator and the switch construct.	3.5 - didn't have record along with switch pattern matching
3.6	Create and use interfaces, identify functional interfaces, and utilize private, static, and default interface methods.	3.6
3.7	Create and use enum types with fields, methods, and constructors.	3.7
Handling Exceptions
4.1	Handle exceptions using try/catch/finally, try-with-resources, and multi-catch blocks, including custom exceptions.	4.1
Working with Arrays and Collections
5.1	Create arrays, List, Set, Map and Deque collections, and add, remove, update, retrieve and sort their elements.	5.1, minor verbiage changes
Working with Streams and Lambda expressions
6.1	Use Java object and primitive Streams, including lambda expressions implementing functional interfaces, to create, filter, transform, process, and sort data.	6.1, minor verbiage changes
6.2	Perform decomposition, concatenation, and reduction, and grouping and partitioning on sequential and parallel streams.	6.2
Packaging and Deploying Java Code
7.1	Define modules and expose module content, including that by reflection, and declare module dependencies, define services, providers, and consumers.	7.1, minor verbiage changes
7.2	Compile Java code, create modular and non-modular jars, runtime images, and implement migration to modules using unnamed and automatic modules.	7.2, minor verbiage changes
Managing Concurrent Code Execution
8.1	Create both platform and virtual threads. Use both Runnable and Callable objects, manage the thread lifecycle, and use different Executor services and concurrent API to run tasks.	8.1, didn't have platform vs virtual threads
8.2	Develop thread-safe code, using locking mechanisms and concurrent API.	8.2, minor verbiage changes
8.3	Process Java collections concurrently and utilize parallel streams.	8.3, minor verbiage changes
Using Java I/O API
9.1	Read and write console and file data using I/O streams.	9.1, minor verbiage changes
9.2	Serialize and de-serialize Java objects.	9.2
9.3	Construct, traverse, create, read, and write Path objects and their properties using the java.nio.file API.	9.3, minor verbiage changes
Implementing Localization
10.1	Implement localization using locales and resource bundles. Parse and format messages, dates, times, and numbers, including currency and percentage values.	11.1, minor verbiage changes

OCP 17 829 Objective	OCP 17 829 Text	Java 21 Objective and Comments
Handling date, time, text, numeric and boolean values
1.1	Use primitives and wrapper classes including Math API, parentheses, type promotion, and casting to evaluate arithmetic and boolean expressions	1.1, minor verbiage changes
1.2	Manipulate text, including text blocks, using String and StringBuilder classes	1.2
1.3	Manipulate date, time, duration, period, instant and time-zone objects using Date-Time API	1.3, added daylight savings
Controlling Program Flow
2.1	Create program flow control constructs including if/else, switch statements and expressions, loops, and break and continue statements	2.1
Utilizing Java Object-Oriented Approach
3.1	Declare and instantiate Java objects including nested class objects, and explain the object life-cycle including creation, reassigning references, and garbage collection	3.1
3.2	Create classes and records, and define and use instance and static fields and methods, constructors, and instance and static initializers	3.2
3.3	Implement overloading, including var-arg methods	3.3, minor verbiage changes
3.4	Understand variable scopes, use local variable type inference, apply encapsulation, and make objects immutable	3.4
3.5	Implement inheritance, including abstract and sealed classes. Override methods, including that of Object class. Implement polymorphism and differentiate object type versus reference type. Perform type casting, identify object types using instanceof operator and pattern matching	3.5, added record along with switch pattern matching
3.6	Create and use interfaces, identify functional interfaces, and utilize private, static, and default interface methods	3.6
3.7	Create and use enumerations with fields, methods and constructors	3.7
Handling Exceptions
4.1	Handle exceptions using try/catch/finally, try-with-resources, and multi-catch blocks, including custom exceptions	4.1
Working with Arrays and Collections
5.1	Create Java arrays, List, Set, Map, and Deque collections, and add, remove, update, retrieve and sort their elements	5.1, minor verbiage changes
Working with Streams and Lambda expressions
6.1	Use Java object and primitive Streams, including lambda expressions implementing functional interfaces, to supply, filter, map, consume, and sort data	6.1, minor verbiage changes
6.2	Perform decomposition, concatenation and reduction, and grouping and partitioning on sequential and parallel streams	6.2
Packaging and deploying Java code and use the Java Platform Module System
7.1	Define modules and their dependencies, expose module content including for reflection. Define services, producers, and consumers	7.1, minor verbiage changes
7.2	Compile Java code, produce modular and non-modular jars, runtime images, and implement migration using unnamed and automatic modules	7.2, minor verbiage changes
Managing concurrent code execution
8.1	Create worker threads using Runnable and Callable, manage the thread lifecycle, including automations provided by different Executor services and concurrent API	8.1, added platform vs virtual threads
8.2	Develop thread-safe code, using different locking mechanisms and concurrent API	8.2, minor verbiage changes
8.3	Process Java collections concurrently including the use of parallel streams	8.3, minor verbiage changes
Using Java I/O API
9.1	Read and write console and file data using I/O Streams	9.1, minor verbiage changes
9.2	Serialize and de-serialize Java objects	9.2
9.3	Create, traverse, read, and write Path objects and their properties using java.nio.file API	9.3, minor verbiage changes
Accessing databases using JDBC
10.1	Create connections, create and execute basic, prepared and callable statements, process query results and control transactions using JDBC API	n/a - Removed
Implementing Localization
11.1	Implement localization using locales, resource bundles, parse and format messages, dates, times, and numbers including currency and percentage values	10.1, minor verbiage changes

Thanks for the mapping!
Any idea why they numbered it 1Z0-830 instead of 1Z0-839?

Paul Anilprem wrote:Thanks for the mapping!
Any idea why they numbered it 1Z0-830 instead of 1Z0-839?

Maybe they realized they would run out of numbers if they advanced it by ten every two years? I don't know if that was the reason, but it's what I think of!

I wonder what is Oracle's thought process in picking exam topics. Most non-trivial applications use JDBC either directly or indirectly yet it is removed from the objectives while most applications do not use modules but Oracle wants the candidates to have deep knowledge of modules! Same goes for Serialization.
BTW, when I say "most", I do not have any real statistical data. Just what I observed.

Paul Anilprem wrote:I wonder what is Oracle's thought process in picking exam topics. Most non-trivial applications use JDBC either directly or indirectly yet it is removed from the objectives while most applications do not use modules but Oracle wants the candidates to have deep knowledge of modules! Same goes for Serialization.

The questions about JDBC were often not practical.  For example, I don't anyone that uses TYPE_SCROLL_INSENSITIVE or CONCUR_UPDATABLE, but they've been on the exam.  They also had questions about Statement, whereas PreparedStatement is often preferred for performance and security reasons.  In short, I was in favor of removing JDBC because of quality issues, but to my surprise, that did not weigh into their decision to remove it.  

In theory, modules is the future of Java, but I rarely see professionals working with them so you're guess is as good as mind.

For serialization, there are some interesting topics there, but I don't know many developers who go deep on serialization (or that use the built-in Java serialization).  A lot of people use Jackson/Gson.