Java SE 11 Developer study guide
Java SE 11 Developer · Work through your exam, one topic at a time.
The Java SE 11 Developer credential is Oracle's professional-level certification for programmers who already write Java and want independent proof that they can build, refactor, and debug real applications on Java SE 11. It is aimed at developers with hands-on experience across the language and core libraries, not at beginners learning syntax. The Java SE 11 Developer study guide has 12 sections and about 4,042 words.
01Working with Java Data Types
The exam tests whether you can pick the right type, predict promotion and boxing behaviour, and know exactly what var may and may not do. Java has eight primitives: byte, short, char (16-bit unsigned), int, long, float, double, boolean.
401 words, about 2 min02Controlling Program Flow
This domain checks whether you can predict exactly which branches and iterations execute, including fall-through and labelled jumps. The if condition must be boolean - Java has no truthiness, so if (x = 0) is a compile error when x is an int.
378 words, about 2 min03Java Object-Oriented Approach
The exam probes encapsulation, inheritance mechanics, interface evolution and the exact order in which objects are initialized. Access goes private, package-private (no modifier), protected, public.
346 words, about 2 min04Exception Handling and Assertions
This domain tests the checked/unchecked split, try-with-resources semantics, and when assertions actually execute. Throwable splits into Error (JVM problems - do not catch) and Exception.
342 words, about 2 min05Working with Arrays and Collections
The exam checks array semantics, which collection fits which job, and the mutability rules of factory methods. new int[3] is zero-filled; int[] a = {1,2}; is allowed only in a declaration, otherwise new int[]{1,2} .
294 words, about 1 min06Working with Streams and Lambda Expressions
This domain tests lambda target typing, method reference forms, pipeline laziness and collector behaviour. A lambda needs a target type: an interface with exactly one abstract method.
343 words, about 2 min07Java SE 11 Platform Module System
The exam checks that you can write and reason about module-info.java , and that you know how the module path differs from the class path. A module is described by module-info.java at the root of its source tree, one per module.
365 words, about 2 min08Concurrency
This domain tests thread creation, the Java memory model, safe coordination and the concurrency utilities. Thread takes a Runnable; start() launches a new thread while calling run() directly executes on the caller.
330 words, about 2 min09Java I/O API
The exam tests byte versus character streams, the NIO.2 Files API, and serialization mechanics. InputStream and OutputStream handle bytes; Reader and Writer handle characters with a charset.
295 words, about 1 min10Secure Coding in Java SE Applications
The exam tests whether you validate input, protect secrets, and use the platform's secure APIs rather than convenient ones. Treat all external input as hostile.
335 words, about 2 min11Localization and Formatting
The exam checks bundle lookup order, locale-sensitive formatting, and which formatter classes are thread-safe. Locale combines language and country, e.g.
272 words, about 1 min12Annotations and Functional Interfaces
This domain tests built-in annotation rules, how to declare and reflect on custom annotations, and the shape of functional interfaces. @Override catches signature mistakes but is optional.
341 words, about 2 min