Learn two different ways to format an instant as a string – one using core Java and the other using the Joda-Time library.
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Baeldung Editor
Kevin Gilmore
Kevin Gilmore is a software developer in Austin, Texas, and he's been writing code in Java for over 15 years. For the past five years, he has focused mainly on back-end web development using the Spring framework, Spring Data with JPA and Hibernate, Spring MVC, and Spring Boot, and prior to that, he dabbled in DevOps before DevOps was cool. When he's not creating software, he enjoys music, sports, and writing flash fiction and poetry.
Here's what I've reviewed (so far):
Baeldung on Java
- All
- Java (29)
- Spring Boot (22)
- Spring (21)
- Testing (18)
- Spring MVC (17)
- Core Java (15)
- REST (13)
- Algorithms (12)
- Spring Security (11)
- Persistence (10)
- DevOps (10)
- Data (10)
- Spring Data (9)
- Java String (7)
- Java Collections (7)
- Jakarta EE (7)
- Maven (6)
- Java IO (6)
- Spring Web (5)
- Security (5)
- NoSQL (5)
- Logging (5)
- Java Concurrency (5)
- HTTP Client-Side (5)
- Cloud (5)
- Architecture (5)
- Spring Persistence (4)
- Java Dates (4)
- Java Array (4)
- Jackson (4)
- JPA (4)
- XML (3)
- Spring Cloud (3)
- Reactive (3)
- Java Streams (3)
- Java Numbers (3)
- Java Map (3)
- JSON (3)
- JVM (2)
- IDE (2)
- Java List (1)
- Groovy (1)
- Gradle (1)
HttpMessageNotWritableException: No Converter for [class …] With Preset Content-Type
Filed under Spring Web
Learn what causes Spring to throw HttpMessageNotWritableException with the message “No converter for [class …] with preset Content-Type” and how to solve it.
An Introduction to Domain Graph Service (DGS) Framework
Filed under Spring Boot
Learn how to use the Domain Graph Service (DGS) Framework from Netflix to build a simple Spring Boot GraphQL service in Java.
Check if a String Ends with a Certain Pattern in Java
Filed under Java String
Learn how to check if a String ends in a certain pattern in Java using core Java methods as well as Apache Commons Lang’s StringUtils class.
Split a String Every n Characters in Java
Filed under Java String
Learn several ways to split a string after every n characters in Java.
Is Cassandra a Column-Oriented or Column-Family Database?
Filed under NoSQL
Learn how Cassandra stores data in a partitioned row store and how this differs from a column-oriented data store.
Kafka Streams With Spring Boot
Filed under Spring Boot
Learn how to build a simple event-driven Spring Boot application to process messages with Kafka Streams.
Generate PDF from Swagger API Documentation
Filed under REST
Learn how to generate a PDF document from an OpenAPI Swagger definition using Maven plugins and the online Swagger To PDF tool.
Adding a Column to an Excel Sheet Using Apache POI
Filed under Java IO
Learn how to add a column to an Excel sheet using Java with the Apache POI library.
Baeldung on Linux
- All
- Scripting (9)
- Files (5)
- Search (3)
- Administration (3)
- File Searching (2)
- Text Processing (1)
- Processes (1)
- Networking (1)
- Network Configuration (1)
- File Permissions (1)
- File Editing (1)
Find the Script’s Filename Within the Same Script in Bash
Filed under Scripting
Learn a few ways to find the filename of a running Bash script from within the script itself.
DNS Caching in Linux
Filed under Network Configuration
Learn how to configure DNS caching in Linux using the built-in systemd-resolved facility, or using an installable tool such as bind9 or dnsmasq.
Interprocess Communication With Unix Sockets
Filed under Networking
Learn what Unix Sockets are and how to create and interact with them using common Linux utilities.
Replacing Whitespaces With Tabs in a File in Linux
Filed under Text Processing
Learn several commands and tools for replacing whitespaces with tabs in a file.
Convert Hex to ASCII Characters in the Linux Shell
Filed under Scripting
Learn several ways to convert hex characters to ASCII from the Linux command line.
Parse Command Line Arguments in Bash
Filed under Scripting
Learn to parse command-line arguments in Bash scripts using the getopts built-in function and the GNU getopt utility.
Fixing the “Too many open files” Error in Linux
Filed under Administration, Files
Learn about the Linux system limits placed on file descriptors in the context of understanding and resolving the “Too many open files” error.
Count the Number of Directories in a Specific Directory
Filed under Files
Learn a few different Linux commands for counting the number of directories contained inside a specific directory or directory tree.
Checking if a Linux Environment Variable Is Set or Not
Filed under Scripting
Learn how to check whether a particular environment variable is set or not in Linux.
Baeldung on Scala
- All
- Functional Programming (2)
- Scala OOP (1)
- Scala Core (1)
- Scala Basics (1)
- Play Framework (1)
- Build Tools (1)
- Apache Spark (1)
Excluding Dependencies with SBT
Filed under Build Tools
Learn how to exclude transitive dependencies when building a Scala project with SBT.
map vs. flatMap in Apache Spark
Filed under Apache Spark
Learn the difference between Apache Spark’s map and flatMap functions in Scala.
Dependency Injection with Play
Filed under Play Framework
Learn how to use dependency injection in Play framework with built-in Google Guice, as well as with MacWire’s compile-time dependency injection.
Introduction to Functional Programming in Scala
Filed under Functional Programming
Learn the basics of functional programming support in Scala.
Difference Between Class and Case Class in Scala
Filed under Scala OOP
Learn how to use case classes as immutable data containers in Scala and how they differ from regular classes.
Guide to lazy val in Scala
Filed under Scala Basics
Learn how Scala implements its lazy val feature and some problems you may encounter when using it.
Higher-Order Functions in Scala
Filed under Functional Programming
Learn how to use higher-order functions from the Scala standard library and how to write your own higher-order functions.
Regular Expressions in Scala
Filed under Scala Core
Learn how to match regular expressions in Scala using the Regex class from the Scala standard library.
Baeldung on Computer Science
- All
- Trees (2)
- Programming (2)
- Data Structures (2)
- Artificial Intelligence (2)
- Security (1)
- Path Finding (1)
- OS (1)
- Machine Learning (1)
- Graph Traversal (1)
- Algorithms (1)
Hashing a Tree Structure
Filed under Trees
Learn how to build a hash function for a tree structure.
Introduction to SAML
Filed under Security
Learn about SAML 2.0, one of the most common standards used when implementing SSO solutions.
How to Design Deep Convolutional Neural Networks?
Filed under Artificial Intelligence
Learn the basic concepts behind convolutional neural networks, commonly used in computer vision tasks, and how to construct them.
Full, Para, and Hardware-Assisted Virtualization Compared
Filed under OS
Learn the key aspects of three of the more common server virtualization techniques and how they differ.
Find the Next Higher Number
Filed under Algorithms
Learn an algorithm for finding the next higher number that can be formed using the digits of a given non-negative number.
How to Check If a Binary Tree Is Symmetric?
Filed under Data Structures, Trees
Learn how to check whether a binary tree structure is symmetric, using either a recursive solution or an iterative approach.
Feature Scaling
Filed under Machine Learning
Learn how to apply feature scaling during the data transformation phase to improve Machine Learning results.
PCA: Principal Component Analysis
Filed under Artificial Intelligence
Learn about principal component analysis and how to use it to reduce the dimensionality of a dataset and discover its principal aspects.
Functional Programming
Filed under Programming
Learn the core concepts of the functional programming paradigm and how it compares to OOP.
Baeldung on Kotlin
- All
- Kotlin-Java Interop (3)
- Kotlin Strings (2)
- Kotlin Collections (2)
- Testing (1)
- Spring (1)
- Libraries (1)
- Kotlin IO (1)
- Kotlin Functions (1)
- Kotlin Concurrency (1)
- Kotlin Classes and Objects (1)
- Kotlin (1)
- Asynchronous Programming (1)
Get Character by Index in a Kotlin String
Filed under Kotlin Strings
Learn several ways to get a character from a Kotlin String by index.
Convert List to String in Kotlin
Filed under Kotlin Collections, Kotlin Strings
Learn several ways to convert Lists to Strings using only core Kotlin and the Collections API.
Launching Kotlin Coroutines: With a Result or a Side Effect
Filed under Asynchronous Programming
Learn the differences between how the async and launch scope functions behave when running coroutines in Kotlin.
Guide to Kotlin’s yield Function
Filed under Kotlin Concurrency
Learn how the yield function works in Kotlin through examples with two use cases: building sequences and cooperative multitasking.
Log Request/Response Body in Spring WebFlux with Kotlin
Filed under Spring
Learn how to log request and response bodies of a Spring Webflux application in Kotlin using a custom WebFilter.
Java vs. Kotlin
Filed under Kotlin-Java Interop
Learn several key differences between Java and Kotlin, the two most popular languages for the JVM.
Difference Between Classes and Singleton Objects in Kotlin
Filed under Kotlin Classes and Objects
Learn how Kotlin classes and objects differ at both the language and bytecode levels.
Converting a Kotlin File to Java
Filed under Kotlin-Java Interop
Learn how to convert a Kotlin file to Java using the Fernflower tool from the command line or within IntelliJ IDEA.
Console I/O in Kotlin
Filed under Kotlin IO
Learn how to handle I/O in Kotlin using its standard library or one of several classes from the Java standard library.
Baeldung on Ops
- All
- Jenkins (2)
How to Configure RBAC in Jenkins
Filed under Jenkins
Explore various ways to configure RBAC for Jenkins users.
Setting Up a Jenkins Slave Node
Filed under Jenkins
Understand the concept of distributed builds in Jenkins Architecture and how we can configure Jenkins master-slave architecture.