Learn how to extend Enums in Java.
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Baeldung Author
Kai Yuan
Kai Yuan has been developing software for more than 20 years, mainly working on enterprise Kotlin and Java applications. He’s been using Linux for over 20 years and is a big fan of the Vim editor. Kai also enjoys helping out on StackOverflow and currently lives in Hamburg.
Here's what I've written (so far):
Baeldung on Java
- All
- Java String (42)
- Java List (25)
- Java Array (18)
- Core Java (18)
- Java Numbers (16)
- Java Map (16)
- Java IO (14)
- Java (11)
- Algorithms (10)
- Java Streams (8)
- Testing (7)
- Java Collections (5)
- Persistence (4)
- Maven (4)
- Spring Boot (2)
- Java Concurrency (2)
- XML (1)
- Spring Persistence (1)
- Networking (1)
- Java Web (1)
- Jakarta EE (1)
- Jackson (1)
- IDE (1)
AbstractMethodError in Java
Filed under Java
Take a closer look at Java’s AbstractMethodError and understand what it is and when it may happen
Get Names of Classes Inside a JAR File
Filed under Java
Learn how to get names of classes inside a given JAR file and how to load classes from a JAR file at runtime.
Get the Running Port in Spring Boot
Filed under Spring Boot
Learn how to get the HTTP port programmatically in a Spring Boot application
The Difference Between a.getClass() and A.class in Java
Filed under Core Java
Learn the differences between calling the Object.getClass() method and using the .class syntax
Regular Expressions \s and \s+ in Java
Filed under Java
Learn about the difference between the two regular expressions through examples
Java Compiler Error: illegal start of expression
Filed under Java
See examples that illustrate the main causes of the “illegal start of expression” error and how to fix it
Java Scanner hasNext() vs. hasNextLine()
Filed under Java IO
Learn the differences between Java Scanner’s hasNext() and hasNextLine() methods.
How to Count Duplicate Elements in Arraylist
Filed under Java List
Explore various ways to calculate the count of duplicate elements in a list.
Baeldung on Linux
- All
- Scripting (36)
- Files (32)
- File Editing (21)
- Text Processing (11)
- File Searching (11)
- Processes (10)
- Administration (10)
- Filesystems (6)
- File Viewing (6)
- User Administration (4)
- Search (3)
- File Permissions (3)
- Web (2)
- Security (1)
- File Compression (1)
- Boot Process (1)
How to Limit grep Context to “n” Characters in a Line
Filed under File Searching
Learn how to limit the grep output characters displayed before and after the match.
Guide to Linux dirname Command with Examples
Learn how to use the dirname command in Linux to extract the directory part of a given path.
Guide to Linux basename Command with Examples
Learn about how to use the basename command to determine the file or folder name for one or more paths.
Printing Quote Characters in AWK
Filed under Text Processing
Learn how to print single or double quote characters in AWK scripts.
How to Read the First and the Last Line From Input
Filed under File Viewing
Learn how to extract the first and last lines from an input file using a single command.
Printing Specified Lines From a File
Filed under File Viewing
Learn how to extract specific lines from a file by line numbers using sed and awk.
Replace the First n Matched Instances in a File
Filed under File Editing
Learn how to replace the first n pattern occurrences in a file using sed and awk.
How to Operate on Files Listed in a File
Learn to use various techniques to operate on files listed in a file.
What’s the Meaning of $! in Bash Scripting
Learn the meaning of the special shell variable $!.
Baeldung on Kotlin
- All
- Kotlin Collections (18)
- Kotlin Classes and Objects (10)
- Kotlin Basics (10)
- Kotlin Numbers (9)
- Kotlin Strings (7)
- Kotlin Functions (5)
- Kotlin (4)
- Kotlin Arrays (3)
- Testing (2)
- Functional Programming (2)
- Spring (1)
- Security (1)
- Libraries (1)
- Algorithms (1)
Resolving Compile Error: “Const ‘val’ is only allowed on top level, in named objects, or in companion objects” in Kotlin
Filed under Kotlin Classes and Objects
Learn where and how you can use const val in Kotlin.
Resolving “Type Mismatch Inferred Type is Unit But Void Was Expected” in Kotlin
Filed under Kotlin Functions
Learn how to solve the “Unit but Void was expected” compilation error in Kotlin.
Iterating Enum Entries in Kotlin
Filed under Kotlin Basics
Learn how to loop over the entries of an Enum in Kotlin.
Difference Between clearAllMocks() and unmockkAll() in MockK
Filed under Testing
Learn about the difference between clearAllMocks() and unmockkAll() in MockK and when to use each one.
Serialize Enum Property to JSON in Kotlin
Filed under Libraries
Learn how to serialize a Kotlin enum property to JSON using Kotlin libraries.
Finding First Match in Nested Lists in Kotlin
Filed under Algorithms, Kotlin Collections
Learn how to search through a list of lists in Kotlin to find the first matching element.
Conditional Exception Throwing in Kotlin
Filed under Kotlin
Learn different approaches to throwing an exception when a condition is true in Kotlin.
Pass a Function as Parameter to Another in Kotlin
Filed under Kotlin Functions
Learn about how functions can be passed as parameters to other functions in Kotlin.
Matching Varargs Using MockK in Kotlin
Filed under Testing
Learn how to use the MockK mocking library to match varargs arguments in Kotlin.
Baeldung on Ops
- All
- Git (5)
Remove File From Git Repository Without Deleting It Locally
Filed under Git
Learn how to remove a file or directory from a Git repository but keep its local copy
How to Get the Current Branch Name in Git
Filed under Git
Learn how to get the Git branch name we’re currently working on
Delete a Git Branch Locally and Remotely
Filed under Git
Learn how to delete Git branches
Move Existing, Uncommitted Work to a New Branch in Git
Filed under Git
Learn a couple of quick ways to move uncommitted changes to a new Git branch
Squash the Last X Commits Using Git
Filed under Git
Learn what Git squashing is, talk about when we need to squash commits, and take a closer look at how to squash commits