eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
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Let's get started with a Microservice Architecture with Spring Cloud:

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eBook – Mockito – NPI EA (tag = Mockito)
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Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.

Get started with mocking and improve your application tests using our Mockito guide:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

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eBook – Reactive – NPI EA (cat=Reactive)
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Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:

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eBook – Java Streams – NPI EA (cat=Java Streams)
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Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

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eBook – Jackson – NPI EA (cat=Jackson)
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Do JSON right with Jackson

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eBook – HTTP Client – NPI EA (cat=Http Client-Side)
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Get the most out of the Apache HTTP Client

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eBook – Maven – NPI EA (cat = Maven)
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Get Started with Apache Maven:

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eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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eBook – RwS – NPI EA (cat=Spring MVC)
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Building a REST API with Spring?

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Course – LS – NPI EA (cat=Jackson)
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Get started with Spring and Spring Boot, through the Learn Spring course:

>> LEARN SPRING
Course – RWSB – NPI EA (cat=REST)
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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

>> The New “REST With Spring Boot”

Course – LSS – NPI EA (cat=Spring Security)
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Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.

I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.

You can explore the course here:

>> Learn Spring Security

Course – LSD – NPI EA (tag=Spring Data JPA)
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Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.

Get started with Spring Data JPA through the guided reference course:

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Partner – Moderne – NPI EA (cat=Spring Boot)
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Refactor Java code safely — and automatically — with OpenRewrite.

Refactoring big codebases by hand is slow, risky, and easy to put off. That’s where OpenRewrite comes in. The open-source framework for large-scale, automated code transformations helps teams modernize safely and consistently.

Each month, the creators and maintainers of OpenRewrite at Moderne run live, hands-on training sessions — one for newcomers and one for experienced users. You’ll see how recipes work, how to apply them across projects, and how to modernize code with confidence.

Join the next session, bring your questions, and learn how to automate the kind of work that usually eats your sprint time.

Course – LJB – NPI EA (cat = Core Java)
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Code your way through and build up a solid, practical foundation of Java:

>> Learn Java Basics

Partner – LambdaTest – NPI EA (cat= Testing)
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Distributed systems often come with complex challenges such as service-to-service communication, state management, asynchronous messaging, security, and more.

Dapr (Distributed Application Runtime) provides a set of APIs and building blocks to address these challenges, abstracting away infrastructure so we can focus on business logic.

In this tutorial, we'll focus on Dapr's pub/sub API for message brokering. Using its Spring Boot integration, we'll simplify the creation of a loosely coupled, portable, and easily testable pub/sub messaging system:

>> Flexible Pub/Sub Messaging With Spring Boot and Dapr

1. Overview

Temporary directories come in handy when we need to create a set of files that we can later discard. When we create temporary directories, we can delegate to the operating system where to put them or specify ourselves where we want to place them.

In this short tutorial, we’ll learn how to create temporary directories in Java using different APIs and approaches. All the examples in this tutorial will be performed using plain Java 7+, Guava, and Apache Commons IO.

2. Delegate to the Operating System

One of the most popular approaches used to create temporary directories is to delegate the destination to the underlying operating system. The location is given by the java.io.tmpdir property, and every operating system has its own structure and cleanup routines.

In plain Java, we create a directory by specifying the prefix we want the directory to take:

String tmpdir = Files.createTempDirectory("tmpDirPrefix").toFile().getAbsolutePath();
String tmpDirsLocation = System.getProperty("java.io.tmpdir");
assertThat(tmpdir).startsWith(tmpDirsLocation);

Using Guava, the process is similar, but we can’t specify how we want to prefix our directory:

String tmpdir = Files.createTempDir().getAbsolutePath();
String tmpDirsLocation = System.getProperty("java.io.tmpdir");
assertThat(tmpdir).startsWith(tmpDirsLocation);

Apache Commons IO doesn’t provide a way to create temporary directories. It provides a wrapper to get the operating system temporary directory, and then, it’s up to us to do the rest:

String tmpDirsLocation = System.getProperty("java.io.tmpdir");
Path path = Paths.get(FileUtils.getTempDirectory().getAbsolutePath(), UUID.randomUUID().toString());
String tmpdir = Files.createDirectories(path).toFile().getAbsolutePath();
assertThat(tmpdir).startsWith(tmpDirsLocation);

In order to avoid name clashes with existing directories, we use UUID.randomUUID() to create a directory with a random name.

3. Specifying the Location

Sometimes we need to specify where we want to create our temporary directory. A good example is during a Maven build. Since we already have a “temporary” build target directory, we can make use of that directory to place temporary directories our build might need:

Path tmpdir = Files.createTempDirectory(Paths.get("target"), "tmpDirPrefix");
assertThat(tmpdir.toFile().getPath()).startsWith("target");

Both Guava and Apache Commons IO lack methods to create temporary directories at specific locations.

It’s worth noting that the target directory can be different depending on the build configuration. One way to make it bullet-proof is to pass the target directory location to the JVM running the test.

As the operating system isn’t taking care of the cleanup, we can make use of File.deleteOnExit():

tmpdir.toFile().deleteOnExit();

This way, the file is deleted once the JVM terminates, but only if the termination is graceful.

4. Using Different File Attributes

Like any other file or directory, it’s possible to specify file attributes upon the creation of a temporary directory. So, if we want to create a temporary directory that can only be read by the user that creates it, we can specify the set of attributes that will accomplish that:

FileAttribute<Set> attrs = PosixFilePermissions.asFileAttribute(
  PosixFilePermissions.fromString("r--------"));
Path tmpdir = Files.createTempDirectory(Paths.get("target"), "tmpDirPrefix", attrs);
assertThat(tmpdir.toFile().getPath()).startsWith("target");
assertThat(tmpdir.toFile().canWrite()).isFalse();

As expected, Guava and Apache Commons IO do not provide a way to specify the attributes when creating temporary directories.

It’s also worth noting that the previous example assumes we are under a Posix Compliant Filesystem such as Unix or macOS.

More information about file attributes can be found in our Guide to NIO2 File Attribute APIs.

5. Conclusion

In this short tutorial, we explored how to create temporary directories in plain Java 7+, Guava, and Apache Commons IO. We saw that plain Java is the most flexible way to create temporary directories as it offers a wider range of possibilities while keeping the verbosity to a minimum.

The code backing this article is available on GitHub. Once you're logged in as a Baeldung Pro Member, start learning and coding on the project.
Baeldung Pro – NPI EA (cat = Baeldung)
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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
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The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints. Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:

>> Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

Explore the eBook

Course – LS – NPI EA (cat=REST)

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Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (tag=Refactoring)
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Modern Java teams move fast — but codebases don’t always keep up. Frameworks change, dependencies drift, and tech debt builds until it starts to drag on delivery. OpenRewrite was built to fix that: an open-source refactoring engine that automates repetitive code changes while keeping developer intent intact.

The monthly training series, led by the creators and maintainers of OpenRewrite at Moderne, walks through real-world migrations and modernization patterns. Whether you’re new to recipes or ready to write your own, you’ll learn practical ways to refactor safely and at scale.

If you’ve ever wished refactoring felt as natural — and as fast — as writing code, this is a good place to start.

eBook Jackson – NPI EA – 3 (cat = Jackson)