Baeldung Pro – NPI EA (cat = Baeldung)
announcement - icon

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.

Partner – Microsoft – NPI EA (cat = Baeldung)
announcement - icon

Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.

Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.

To learn more about Java features on Azure Container Apps, visit the documentation page.

You can also ask questions and leave feedback on the Azure Container Apps GitHub page.

Partner – Microsoft – NPI EA (cat= Spring Boot)
announcement - icon

Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.

Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.

To learn more about Java features on Azure Container Apps, you can get started over on the documentation page.

And, you can also ask questions and leave feedback on the Azure Container Apps GitHub page.

Partner – Orkes – NPI EA (cat=Spring)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

Partner – Orkes – NPI EA (tag=Microservices)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
announcement - icon

Let's get started with a Microservice Architecture with Spring Cloud:

>> Join Pro and download the eBook

eBook – Mockito – NPI EA (tag = Mockito)
announcement - icon

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:

Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
announcement - icon

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 – Reactive – NPI EA (cat=Reactive)
announcement - icon

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:

>> Join Pro and download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
announcement - icon

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 – Jackson – NPI EA (cat=Jackson)
announcement - icon

Do JSON right with Jackson

Download the E-book

eBook – HTTP Client – NPI EA (cat=Http Client-Side)
announcement - icon

Get the most out of the Apache HTTP Client

Download the E-book

eBook – Maven – NPI EA (cat = Maven)
announcement - icon

Get Started with Apache Maven:

Download the E-book

eBook – Persistence – NPI EA (cat=Persistence)
announcement - icon

Working on getting your persistence layer right with Spring?

Explore the eBook

eBook – RwS – NPI EA (cat=Spring MVC)
announcement - icon

Building a REST API with Spring?

Download the E-book

Course – LS – NPI EA (cat=Jackson)
announcement - icon

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

>> LEARN SPRING
Course – RWSB – NPI EA (cat=REST)
announcement - icon

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)
announcement - icon

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 – All Access – NPI EA (cat= Spring)
announcement - icon

All Access is finally out, with all of my Spring courses. Learn JUnit is out as well, and Learn Maven is coming fast. And, of course, quite a bit more affordable. Finally.

>> GET THE COURSE
Course – LSD – NPI EA (tag=Spring Data JPA)
announcement - icon

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:

>> CHECK OUT THE COURSE

Partner – LambdaTest – NPI EA (cat=Testing)
announcement - icon

End-to-end testing is a very useful method to make sure that your application works as intended. This highlights issues in the overall functionality of the software, that the unit and integration test stages may miss.

Playwright is an easy-to-use, but powerful tool that automates end-to-end testing, and supports all modern browsers and platforms.

When coupled with LambdaTest (an AI-powered cloud-based test execution platform) it can be further scaled to run the Playwright scripts in parallel across 3000+ browser and device combinations:

>> Automated End-to-End Testing With Playwright

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
announcement - icon

Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

>> EXPLORE ACCESS NOW

Course – Spring Sale 2025 – NPI (cat=Baeldung)
announcement - icon

Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

>> EXPLORE ACCESS NOW

1. Overview

When we manipulate Strings in Java, we often need to remove whitespace from a String.

In this tutorial, we’ll explore common scenarios for removing whitespace from a String in Java.

2. Introduction to the Problem

To understand the problem easier, let’s first see a string example:

String myString = "   I    am a    wonderful String     !   ";

The example above shows that the myString variable contains multiple leading, trailing spaces, and whitespace characters in the middle.

Usually, when we need to deal with a string like myString in Java, we often face these two requirements:

  • removing all whitespace characters from the given string -> “IamawonderfulString!”
  • replacing consecutive whitespace characters with a single space, and removing all leading and trailing whitespace characters -> “I am a wonderful String !”

Next, we’ll address two approaches for each case: using the handy replaceAll() method from the String class, and the StringUtils class from the widely used Apache Commons Lang3 library.

To keep it simple in this tutorial, we won’t cover whitespace characters in the Unicode character set when we talk about whitespace. Furthermore, we’ll use test assertions to verify each solution.

Now let’s see them in action.

3. Removing All Whitespace From a String

3.1. Using String.replaceAll()

First, we’ll remove all whitespace from a string using the replaceAll() method.

replaceAll() works with regular expressions (regex). We can use the regex character class ‘\s‘ to match a whitespace character. We can replace each whitespace character in the input string with an empty string to solve the problem: inputString.replaceAll(“\\s”, “”).

Then we’ll create a test to see if this idea works with our example string:

String result = myString.replaceAll("\\s", "");
assertThat(result).isEqualTo("IamawonderfulString!");

If we run the test, it passes. So the replaceAll() method solves the problem. Next, let’s solve the problem using Apache Commons Lang3.

3.2. Using the Apache Commons Lang3 Library

The Apache Commons Lang3 library ships with a StringUtils utility, which allows us to manipulate strings conveniently.

To get started using Apache Commons Lang 3, let’s add the Maven dependency:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.14.0</version>
</dependency>

If we check the methods in the StringUtils class, there’s one method called deleteWhitespace(). The name implies that it’s the method we’re looking for.

Next, we’ll remove all whitespace from a string using StringUtils.deleteWhitespace():

String result = StringUtils.deleteWhitespace(myString);
assertThat(result).isEqualTo("IamawonderfulString!");

The test passes when we execute it. So the deleteWhitespace() does the job.

4. Replacing Consecutive Whitespace Characters With One Single Space

4.1. Using String.replaceAll()

Now let’s look at the other scenario. We can solve this problem in two steps:

  • replacing consecutive whitespace with one single space
  • trimming the result of the first step

It’s worth mentioning that we can also first trim the input string, and then replace consecutive whitespace. So it doesn’t matter which step we take first.

For the first step, we can still use replaceAll() with a regex to match consecutive whitespace characters and set one space as the replacement.

The regex ‘\s+’ matches one or more whitespace characters. Therefore, we can call the replaceAll(“\\s+”, ” “) method to finish the first step. Then we can invoke the String.trim() method to apply the trim operation.

Next, we’ll create a test to check if our idea can solve the problem. To make it clear, we write two assertions for the two steps:

String result = myString.replaceAll("\\s+", " ");
assertThat(result).isEqualTo(" I am a wonderful String ! ");
assertThat(result.trim()).isEqualTo("I am a wonderful String !");

If we run it, the test passes. So the approach works as expected.

Finally, let’s solve the problem using the Apache Commons Lang 3 library.

4.2. Using the Apache Commons Lang3 Library

The StringUtils.normalizeSpace() method trims the input string and then replaces sequences of whitespace characters with a single space. Therefore, we can directly call this method to solve the problem:

String result = StringUtils.normalizeSpace(myString);
assertThat(result).isEqualTo("I am a wonderful String !");

The test passes when we execute it. As we can see, StringUtils.normalizeSpace() is pretty straightforward to use.

5. Remove Only Leading and Trailing Whitespace

5.1. Using strip()

The strip() method is used to remove leading and trailing whitespace from a string. This method was introduced in Java 11 and is more Unicode-aware than the older trim() method, which only removes the standard ASCII whitespace characters.

Let’s see how we can use this method to remove leading and trailing whitespace from a string:

String result = myString.strip();
assertThat(result).isEqualTo("I am a wonderful String !");

In this example, strip() removes only the leading and trailing whitespace. It doesn’t remove whitespace within the string.

5.2. Using stripLeading() and stripTrailing()

Java 11 also introduced stripLeading() and stripTrailing() methods to remove whitespace only from the beginning or end of the string, respectively:

String result = myString.stripLeading();
assertThat(result).isEqualTo("I am a wonderful String !   ");

String result = myString.stripTrailing();
assertThat(result).isEqualTo("   I am a wonderful String !");

In the above code example, we remove the leading and trailing whitespaces using stripLeading() and stripTrailing() methods.

6. Conclusion

In this article, we learned how to remove whitespace characters from a string in Java.

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)
announcement - icon

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.

Partner – Microsoft – NPI EA (cat = Spring Boot)
announcement - icon

Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.

Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.

To learn more about Java features on Azure Container Apps, visit the documentation page.

You can also ask questions and leave feedback on the Azure Container Apps GitHub page.

Partner – Orkes – NPI EA (cat = Spring)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

Partner – Orkes – NPI EA (tag = Microservices)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
announcement - icon

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)
announcement - icon

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)
announcement - icon

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)
announcement - icon

Working on getting your persistence layer right with Spring?

Explore the eBook

Course – LS – NPI EA (cat=REST)

announcement - icon

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

>> CHECK OUT THE COURSE

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
announcement - icon

Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

>> EXPLORE ACCESS NOW

Course – Spring Sale 2025 – NPI (All)
announcement - icon

Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

>> EXPLORE ACCESS NOW

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