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:
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:
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:
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:
Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:
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:
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:
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.
Regression testing is an important step in the release process, to ensure that new code doesn't break the existing functionality. As the codebase evolves, we want to run these tests frequently to help catch any issues early on.
The best way to ensure these tests run frequently on an automated basis is, of course, to include them in the CI/CD pipeline. This way, the regression tests will execute automatically whenever we commit code to the repository.
In this tutorial, we'll see how to create regression tests using Selenium, and then include them in our pipeline using GitHub Actions:, to be run on the LambdaTest cloud grid:
1. Overview
In this article, we’ll be looking at the Jasypt (Java Simplified Encryption) library.
Jasypt is a Java library which allows developers to add basic encryption capabilities to projects with minimum effort, and without the need of having an in-depth knowledge about implementation details of encryption protocols.
2. Using Simple Encryption
Consider we’re building a web application in which user submits an account private data. We need to store that data in the database, but it would be insecure to store plain text.
One way to deal with it is to store an encrypted data in the database, and when retrieving that data for a particular user decrypt it.
To perform encryption and decryption using a very simple algorithm, we can use a BasicTextEncryptor class from the Jasypt library:
BasicTextEncryptor textEncryptor = new BasicTextEncryptor();
String privateData = "secret-data";
textEncryptor.setPasswordCharArray("some-random-data".toCharArray());Then we can use an encrypt() method to encrypt the plain text:
String myEncryptedText = textEncryptor.encrypt(privateData);
assertNotSame(privateData, myEncryptedText);If we want to store a private data for given user in the database, we can store a myEncryptedText without violating any security restrictions. Should we want to decrypt data back to a plain text, we can use a decrypt() method:
String plainText = textEncryptor.decrypt(myEncryptedText);
assertEquals(plainText, privateData);We see that decrypted data is equal to plain text data that was previously encrypted.
3. One-way Encryption
The previous example is not an ideal way to perform authentication, that is when we want to store a user password. Ideally, we want to encrypt the password without a way to decrypt it. When the user tries to log into our service, we encrypt his password and compare it with the encrypted password that is stored in the database. That way we do not need to operate on plain text password.
We can use a BasicPasswordEncryptor class to perform the one-way encryption:
String password = "secret-pass";
BasicPasswordEncryptor passwordEncryptor = new BasicPasswordEncryptor();
String encryptedPassword = passwordEncryptor.encryptPassword(password);
Then, we can compare an already encrypted password with a password of a user that perform login process without a need to decrypt password that is already stored in the database:
boolean result = passwordEncryptor.checkPassword("secret-pass", encryptedPassword);
assertTrue(result);4. Configuring Algorithm for Encryption
We can use a stronger encryption algorithm but we need to remember to install Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files for our JVM (installation instructions are included in the download).
In Jasypt we can use strong encryption by using a StandardPBEStringEncryptor class and customize it using a setAlgorithm() method:
StandardPBEStringEncryptor encryptor = new StandardPBEStringEncryptor();
String privateData = "secret-data";
encryptor.setPassword("some-random-passwprd");
encryptor.setAlgorithm("PBEWithMD5AndTripleDES");Let’s set the encryption algorithm to be PBEWithMD5AndTripleDES.
Next, the process of encryption and decryption looks the same as the previous one using a BasicTextEncryptor class:
String encryptedText = encryptor.encrypt(privateData);
assertNotSame(privateData, encryptedText);
String plainText = encryptor.decrypt(encryptedText);
assertEquals(plainText, privateData);5. Using Multi-Threaded Decryption
When we’re operating on the multi-core machine we want to handle processing of decryption in parallel. To achieve a good performance we can use a PooledPBEStringEncryptor and the setPoolSize() API to create a pool of digesters. Each of them can be used by the different thread in parallel:
PooledPBEStringEncryptor encryptor = new PooledPBEStringEncryptor();
encryptor.setPoolSize(4);
encryptor.setPassword("some-random-data");
encryptor.setAlgorithm("PBEWithMD5AndTripleDES");It’s good practice to set pool size to be equal to the number of cores of the machine. The code for encryption and decryption is the same as previous ones.
6. Usage in Other Frameworks
A quick final note is that the Jasypt library can be integrated with a lot of other libraries, including of course the Spring Framework.
We only need to create a configuration to add encryption support into our Spring application. And if we want to store sensitive data into the database and we are using Hibernate as the data access framework, we can also integrate Jasypt with it.
Instructions about these integrations, as well as with some other frameworks, can be found in the Guides section on the Jasypt’s home page.
7. Conclusion
In this article, we were looking at the Jasypt library that helps us create more secure applications by using an already well know and tested cryptography algorithms. It is covered with the simple API that is easy to use.
