Java

Java

Java is a general-purpose programming language intended to let application developers write once and run anywhere.

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Explain Runtime Error with AI Assistant
Let AI Assistant explain runtime errors to you

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Interactive rebase
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

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Rename bookmark
Rename an existing bookmark

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CamelCase in code completion
Use CamelCase in code completion

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Extract Method
Extract code to a new method

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Generate a Test Class
Generate a new test class from your Java class

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Inline Variable
Inline a variable in your code

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Introduce variable
Refactor your code and introduce a new variable

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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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Surround with
Surround your code with common programming constructs

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

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

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Debugging Streams
Visualize the flow of data through a stream

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Recent Files & Locations
Quickly navigate around your recent files & locations

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Clipboard history
Paste a subset or multiple entries from your recent history

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

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

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Inlay hints
Inlay hints provide additional information about your code

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Structural Search
Structural Search and Replace

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Extend Selection
Extend and shrink selection

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Context Actions
Use Alt+Enter to show available context actions

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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

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Navigating Forward & Backward
Move forward and backward between your locations in the code

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Explore project structure with the Dependency Matrix
Exploring project structure with the Dependency Matrix in IntelliJ IDEA

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Interpret the Dependency Matrix
How to interpret the Dependency Matrix

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Introduction
Explore project structure with the Dependency Matrix

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Summary and Shortcuts
Explore project structure with the Dependency Matrix Summary

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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

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Getting started with IntelliJ IDEA
My favourite tips for all new starters in IntelliJ IDEA

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Marco Codes - Building a Text Editor
How to build a terminal-based text editor with Java

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

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Highlighted commands in the terminal
IntelliJ IDEA highlights terminal commands you can run in IntelliJ IDEA

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Expand and Collapse Code
Quickly view specific parts of a class by expanding or collapsing code

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Inspections Widget
The top-right corner of your editor shows you information about the state of your class

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Restore a Deleted Breakpoint
You can restore previously configured breakpoints if you accidentally delete them

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View supertype and subtype hierarchy
You can view supertypes and subtypes in the hierarchy

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Built in Spell Checking
IntelliJ IDEA can spell check and fix errors for you

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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 for us

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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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Find & Select Multiple Occurrences
Select multiple occurrences of the same word and change them all at once

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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 Favourite Photo as 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

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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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Generate a UML diagram
IntelliJ IDEA Ultimate allows you to generate UML diagrams.

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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
Available in preview from Java 17

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Java 17
Get up to speed on Java 17 with our top tips.

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Move 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.

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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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Migrating from the `javax` to `jakarta` namespace
How to transition your application from Java EE to Jakarta EE.

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IntelliJ IDEA 2021.1
Tips to get you productive with the new or improved features in IntelliJ IDEA 2021.1

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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

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

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Working with Maven
Understand how IntelliJ IDEA integrates with Maven.

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Migrating JUnit 4 to JUnit 5
Migrating your JUnit 4 test suite to JUnit 5

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Getting Started with IntelliJ IDEA
Tips for getting started with IntelliJ IDEA

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Commit Changes
Commit your changes to VCS

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Join Lines
Join lines of code together

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Paste a clipboard image onto the Project Window
If you have an image on your clipboard you can paste it straight into the Project Window

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CamelCase in Searching
Use CamelCase to find what you need faster

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Smart Completion
Get type aware completion in your code

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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 constructors and accessor methods
We can quickly generate common code constructs such as Constructors and Get and Set methods

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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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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.

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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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Your First Spring Boot Application
In this tutorial we will use IntelliJ IDEA to create your first "Hello World" Spring Boot application. We'll also discuss what's in your project and why. Spring Boot is a way to create Spring applications easily with some abstractions, some of which we'll touch on in this tutorial.

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Working with Gradle
Understand how IntelliJ IDEA integrates with Gradle.

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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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Generate UML diagrams for your Kotlin code
JVM developers working with Kotlin code can create UML diagrams for their Kotlin classes, just like they could with Java classes

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Use a 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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Use new methods on the Streams API
Inspections can show us new features from Java 16

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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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Java 16
Get up to speed on Java 16 with our top tips.

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Convert from Record
Use quick intentions to convert a record to a class

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Convert class to record
Use inspections to convert classes to Java 16 records

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Create Record
Create a new Java record class

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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

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Use Pattern Matching for instanceof
Inspections can guide us to use new Java features

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Using the IDE Feature Trainer
Learning new things in the IDE

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Add Breakpoint
Easily add breakpoints from the run window

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Add Overload Bool
You can refactor a method to change its signature

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Adjust Code Style
Use quick intentions to adjust your code

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Assert That Import
Use quick intentions to manage imports

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Change Method Signature
Refactor the signature of a method

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Remove Unnecessary Condition
Use quick intentions to remove redundant code

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Copy to, or create a Scratch File
Scratch files persist across all versions of IntelliJ IDEA

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Download a JDK
Download or associate a JDK with your project.

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Drag and Dock Editor tabs
You can move editor tabs around as required

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Turn Editor Breadcrumbs On and Off
Editor breadcrumbs show you your file structure

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Create an Editor Fold
Create an editor fold to hide parts of your class

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Enable Machine Learning for Code Completion
Code completion may be enhanced with ML

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Enable Git Staging
Git Staging is an alternative approach to IntelliJ IDEA Changelists

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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 Variable
Extract code to a variable

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Extract Parameter
Extract code to a parameter

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Find Next Word
Find next word and highlight all instances

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

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Inline a method
Inline a method

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Meaningless Arguments
Use quick intentions to remove redundant code

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Move Line
Move a line throughout your class

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Move Statement
Move a statement around within your method

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Create New Class
Quickly add new classes to your project

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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 script

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Show Virtual Whitespace
Add virtual whitespace to the bottom of a file

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Highlight code and surround it with brackets or quotes
Surround code with brackets and quotes

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Configure Your Editor
Setup the editor to suit your requirements

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Toggle Tool Windows On and Off
Toggle Tool Windows to tailor your interface

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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

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Writing JUnit 5 Tests
Writing JUnit 5 Tests