Java - JetBrains Guide

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Add a Breakpoint

Add breakpoints when you get an exception in your code.

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Create a new class

Create a new class and a new package.

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Inlay Hints

Inlay hints provide additional information about your code.

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JShell

Use JShell in IntelliJ IDEA to quickly evaluate Java expressions.

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Use Pattern Matching for instanceof

Inspections can guide us to use newer Java features.

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Work with records

Create a record, or convert between classes and records.

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Explain Spring Data QL fragment

Let AI Assistant explain a Spring Data QL fragment.

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Inline Completion Shortcut

Choose which key to use for inline AI completion.

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Resolve merge conflict

Let AI Assistant help you resolve merge conflicts.

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Endpoints tool window

Work with endpoints to your application in a dedicated tool window.

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Go to Next Error

Quickly move to the next (or previous) error or warning in the file.

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Fix all in file

Fix all occurrences of the same problem in the file.

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Viewing Modes

Use different viewing modes.

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Explain Cron Fragment with AI Assistant

Using AI Assistant to help you understand a cron fragment.

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Discover Features

Discover AI Assistant Features right inside the IDE.

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Tag files, symbols, etc.

Tag files, symbols and more to make AI Assistant even smarter.

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Use AI Assistant in the Terminal

Ask AI Assistant to generate commands in the Terminal.

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Add logging

Let IntelliJ IDEA add a logger to your class.

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Find Next Word

Find next word and highlight all instances.

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Wrap Chained Method Calls

Start each chained method call on a new line.

Tutorial

Migrating from the `javax` to `jakarta` namespace

How to transition your application from Java EE to Jakarta EE.

Tutorial

Presenting with IntelliJ IDEA.

Tips & tricks to level up your presentation skills with IntelliJ IDEA.

Tutorial

Hello World in IntelliJ IDEA

Create a new Java application and JAR file that prints `Hello World` to the console.

Tutorial

Working with Gradle

Understand how IntelliJ IDEA integrates with Gradle.

Tutorial

Working with Maven

Understand how IntelliJ IDEA integrates with Maven.

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Command in chat

Use predefined command in chat.

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Inline code completion

Let AI Assistant write code for you, using inline code completion.

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Create an Editor Fold

Create an editor fold to hide parts of your class which can make it more readable.

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Generate Overrides for equals(), hashCode() and toString()

We can generate the code to override the equals and hashCode methods.

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Surround With

Surround your code with common programming constructs.

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View supertype and subtype hierarchy

You can view supertypes and subtypes in the hierarchy quickly with your keyboard shortcuts.

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Enable Git Staging

Git Staging is an alternative approach to IntelliJ IDEA Changelists.

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Create New Class

Quickly add new classes to your project.

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Explain Regexp with AI Assistant

Using AI Assistant to help you understand regexp.

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Generate code with AI Assistant

Let AI Assistant write code for you, based on your prompts.

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Extend Selection

Extend and shrink your current code selection.

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Mnemonic bookmark

Use mnemonic bookmarks for easy navigation.

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Run inspection

Run inspection by name. For example, run Vulnerable API usage to see where the vulnerable API of external dependencies is used in your code.

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Custom prompts

Use a custom prompt to let AI Assistant help you.

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Extract Method

Extract code to a new method.

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Presentation Assistant

Use Presentation Assistant to display shortcuts being used.

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Vulnerable API Usage

See whether you are using the vulnerable API of a dependency.

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Download a JDK

Download or Associate a JDK With Your Project.

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Generate constructors and accessor methods

Quickly generate common code constructs such as Constructors, Getters and Setters.

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Generate a UML diagram

IntelliJ IDEA Ultimate allows you to generate UML diagrams.

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Commit Changes

Commit your changes to VCS as you go.

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Disable Usages

Disable the inlay hint for Usages if it's distracting you.

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AI Assistant Chat

You can chat with JetBrains AI Assistant right inside the IDE.

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Find in File

Find a specific name or string in your file.

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Generate Unit Tests

Generate unit tests with AI Assistant.

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Toggle Rendered View

Toggle rendered view for one or all Javadoc comments.

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AI Actions

View and use AI Actions in the editor.

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Close Tabs

Close inactive tabs so you an focus on your current working context.

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Expand and Collapse Code

Quickly view specific parts of a class by expanding or collapsing code blocks.

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Move Statement

Move a statement up or down within the same scope.

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Explain Runtime Error with AI Assistant

Let AI Assistant explain runtime errors to you.

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Interactive Rebase

Clean up your commit history by using interactive rebase in IntelliJ IDEA.

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Write Documentation with AI Assistant

Generate documentation for your code with AI Assistant.

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Dependency Matrix

Explore project structure with the Dependency Matrix.

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Import Multiple Repositories

Import multiple related repositories into one IntelliJ IDEA project.

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Optimize imports

Remove unused imports from your code with one keyboard shortcut.

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Rename Bookmark

Rename an existing bookmark to something more suitable.

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CamelCase in Code Completion

Use CamelCase in code completion to speed up your workflow.

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Generate a Test Class

Generate a new test class from your Java class.

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Inline Variable

Sometimes inlining a variable can make your code more readable.

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Introduce Variable

Refactor your code and introduce a new variable right when you need it.

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Postfix Completion

Postfix completion allows you to keep typing forwards, it minimises the amount of time you spend moving the cursor around while you're coding.

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Live Templates

Use Live Templates to auto-complete common code structures for you.

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Debugging Streams

Visualize the flow of data through a Java stream.

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Understanding the Debugger

Use the debugger to help you understand what your code is doing.

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Recent Files & Locations

Quickly navigate around your recent files & locations to stay in your current working context.

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Clipboard History

Paste a subset or multiple entries such as a list from your recent copy history.

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Data Flow Analysis

Data flow analysis can show us potential errors in our code logic.

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Find in Files

Find a specific string in (a subset of files in) your code.

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Structural Search

Structural Search and Replace is very helpful for finding exactly what you need in your project.

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Context Actions

There are numerous ways to use Context Actions, let's explore some of them.

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Generate Code

Helps you to generate commonly used code constructs.

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Navigate to Test

Go to your matching test class with one keyboard shortcut.

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Navigating Forward & Backward

Move forward and backward between your locations in the code so you don't need to have tabs open.

Tutorial

Explore project structure with the Dependency Matrix

Exploring project structure with the Dependency Matrix in IntelliJ IDEA.

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Summary and Shortcuts

Explore project structure with the Dependency Matrix Summary.

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Introduction

Explore project structure with the Dependency Matrix.

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Interpret the Dependency Matrix

How to interpret the Dependency Matrix.

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Opening the Dependency Matrix

Opening the Dependency Matrix for your project.

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Extract Variable

Extract code to a variable

Tutorial

Getting started with IntelliJ IDEA

My favourite tips for all new starters in IntelliJ IDEA.

Tutorial

Marco Codes - Building a Text Editor

How to build a terminal-based text editor with Java.

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Highlighted Commands in the Terminal

Have you ever wondered which IntelliJ IDEA terminal commands you can run in IntelliJ IDEA?

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Inspections Widget

The top-right corner of your editor shows you information about the state of your class at a glance.

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Restore a Deleted Breakpoint

You can restore previously configured breakpoints if you accidentally delete them.

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Built in Spell Checking

IntelliJ IDEA can spell check and fix errors for you allowing you to focus on problem solving.

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Merge/Unmerge If Statements

Experiment with your code without changing the semantics.

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Code Completion for the Stream API

IntelliJ IDEA can add the stream() call meaning less typing for you.

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Navigating a Long Class

There are various tips and tricks you can use to navigate a long class in IntelliJ IDEA.

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Navigate to the Last Edited Location

Move around the files you're working on quickly with keyboard shortcuts.

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Add Your Favourite Photo as a Background

If you want to look at your favourite photo while coding you can set it as your background image.

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Determining the Return Type of Expression

Type Info is very helpful on a per-expression basis to understand your code.

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Edit a Document in IntelliJ IDEA LightEdit Mode

Use IntelliJ IDEA’s text editing features without creating or opening a dedicated project.

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Inject a Language

Language injections let you work with pieces of code in other languages embedded in your code.

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Pattern Matching for Switch

This feature is available in preview from Java 17.

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New Line

Start a new line below or above your current line with the correct indentation.

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In Editor Doc Rendering

You can render Javadocs directly in the editor including HTML tags, images and links.

Tutorial

Writing Less Code With Live Templates

How you can use live templates to get IntelliJ IDEA to write more code for you.

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Rearranging Code in IntelliJ IDEA.

How you can rearrange code in your classes and projects

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Reformatting Code in IntelliJ IDEA.

Why and how you can reformat code in your projects

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Using the Terminal in IntelliJ IDEA

IntelliJ IDEA has a built-in terminal that you can use to perform a number of functions inside your IDE.

Tutorial

Migrating JUnit 4 to JUnit 5

Migrating your JUnit 4 test suite to JUnit 5.

Playlist

Getting Started with IntelliJ IDEA

Helpful tips for working with IntelliJ IDEA for the first time.

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Join Lines

Join lines of code together in your IDE.

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CamelCase in Searching

Use CamelCase to find what you need faster and save your fingers.

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Smart Completion

Get type aware completion in your code so you can focus on solving problems.

Tutorial

Getting Started with Spring Data JPA

Learn how to use Spring Data JPA to store and retrieve data from your database.

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Generate Test Methods

Generate a test method in your test class.

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Type Into Any Dialog to Search

You can start typing into a dialog box to search, even if there's not a textual search box available.

Tutorial

Your First Spring Boot Application

In this tutorial, we will use IntelliJ IDEA to create your first "Hello World" Spring Boot application.

Tutorial

Writing Tests with Spock

Learn about the Spock testing framework by creating a project that uses Spock to unit test Java code.

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Profile your Application

See how your application is performing with the built-in profiler.

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Run your code with Docker, SSH or WSL

Set a Run Target to change where your code runs.

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Lightweight Inspection Profile on Commit

Fully customise the checks you must perform before you commit your changes to version control.

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Create a Correct Child Sealed Class

Sealed types are a new idea for Java developers, let IntelliJ IDEA guide you in how to create child classes.

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Create a Correct Parent Sealed Class

Sealed types are a new idea for Java developers, let IntelliJ IDEA guide you in how to use them.

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Turn on Preview Features to try new Java Features

The latest versions of Java contain "Preview Features", features that are fully functional but require developer feedback. Try them out in IntelliJ IDEA.

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Identify and Fix Deprecated Calls

IntelliJ IDEA will warn you if you're using deprecated methods, and they will be shown with a strikethrough if they're marked for removal.

Tutorial

Using the IDE Feature Trainer.

Learning new things in the IDE

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Adjust Code Style

Use quick intentions to adjust the style of your code right where your cursor is.

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Add Overload Bool

Refactor a method to change its signature and update your code to reflect the new signature.

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Change Method Signature

Refactor the signature of a method at any time.

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Assert That Import

Use quick intentions to manage imports and keep your code compiling.

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Remove Unnecessary Condition

Use quick intentions to remove redundant code so it's not cluttering up your codebase.

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Drag and Dock Editor Tabs

You can move editor tabs around as required to suit your needs.

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Enable Machine Learning for Code Completion

Code completion may be enhanced with Machine Learning.

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Exclude a Completion Option

Helps to reduce options that are not relevant for your code.

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Extract Field

Extract code to a field.

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Extract Constant

Extract a value to a constant.

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Extract Parameter

Extract code to a parameter.

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Find Usages

Use Find Usages to search for references in your code base.

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Inline a Method

Sometimes inlining a method can improve the readability of your code.

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Meaningless Arguments

Use quick intentions to remove redundant code so it's not cluttering your codebase.

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Move Line

Move a line throughout your class, but watch out for errors!

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Rename an Interface

Renaming in IntelliJ IDEA including comments and texts.

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Replace With var

Use quick intentions to replace a local variable type with `var`.

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Run in Current Context

Run just a file or a single script.

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Show Virtual Whitespace

Add virtual whitespace to the bottom of a file so you can scroll to the end half way up your screen.

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Refactor an Unreachable Statement

Use quick intentions to remove redundant code.

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IntelliJ IDEA Welcome Screen

Get a project from source control, open an existing project, or create a new project.

Tutorial

Writing JUnit 5 Tests

Writing JUnit 5 Tests from start to finish.