Top 9 Java Libraries Will Save Your More Time

IT industries are using hybrid applications mostly in all the companies. Hybrid applications mean, on frontend/backend/database — on these 3 layers they are using some other technologies.

JHipster is a development platform to quickly generate, develop, & deploy modern web applications & microservice architectures. It is a Full Stack Platform for the Modern Developer!

For example, if you want to generate, develop, and deploy Spring/Spring Boot + Angular Web applications, jHipster will perfectly fit your requirement most of the time.

Oh, Dude! this one can save you months of development. I could definitely say that this one is my personal favorite and that I keep a special place for it in my heart. It basically generates your whole application from your front-end to the back-end. The only thing you need to add is the business logic behind the architecture. The main and most important libraries, which are included in the generated project are:

• Spring Boot — helps you accelerate and facilitate application development
• Angular / AngularJS — JavaScript framework

You can find more about JHipster here.

You must be aware of Apache Software Foundation. Yes, It’s the world’s largest open-source foundation and worldwide largest community for developers. There are 350+ projects maintained by this community, Isn’t it so big? Do you still have doubts? Just visit here and try to remember 10 projects daily. It will take a whole 1.5-2 months to remember all the project names.

Maven is a software project management and comprehension tool. Honestly, Maven is really great repository. If you’ve never used Maven before, you’re missing out. Sometimes, I wonder how it was even possible to create enterprise applications before its creation.

Maven can manage all your project dependencies, configurations, and build configurations and even documentation only by specifying them in a single pom.xml file. pom.xml is not just for configuring your project, you can do thousands of things by using it.

Maven’s primary goal is to allow a developer to comprehend the complete state of a development effort in the shortest period of time. To attain this goal, Maven deals with several areas of concern:

• Making the build process easy
• Providing a uniform build system
• Providing quality project information
• Encouraging better development practices

You can find more about Maven here.

We already praised Apache Software Foundation above. Let me come to the point.

Apache Commons is an Apache project focused on all aspects of reusable Java components. We can say it is a whole project focused on creating Java libraries.

There are tonnes of libraries under this project, you can utilize to achieve your purpose according to your requirements. Here is a shortlist of some of the best and most commonly used libraries:

• Commons IO — it is being used for easier execution of input/output operations. Checking at least the ReversedLinesFileReader is definitely worth it.
• Commons CSV — whatever you are developing, at some point you are going to face the necessity of using CSV files. This includes opening, reading, editing, saving, and creating them. I suggest using the RFC 4180 format from the CSVFormat class and UTF-8 encoding when saving/creating files.
• Commons Math: The Apache Commons Mathematics Library — the name says it all: this library contains components allowing advanced mathematics and statistics operations and computations
• Commons CLI — provides API for parsing command-line arguments. Why will you even bother creating an application without the ability to pass parameters and control its behavior?!
• Email — In your normal user-management kind of system, you just need to notify your user using emails, this library will definitely help you to send emails easily with less code. You just need to do configurations for the required parameters.

You can find more about Apache Commons here.

Google-Gson helps convert Java objects to JSON and vice versa.

You don’t need to take care of serialization/deserialization while converting Java Objects into JSON and back. It will automatically handle everything.

This library is especially helpful when developing mobile applications and creating/using REST APIs as well as in any case you would need to convert a Java Object to its JSON representation and vice versa.

Here are some shortlisted goals:

• Extensive support of Java Generics (I know, you hate generics!)
• Allow custom representations for objects
• Provide simple toJson() and fromJson() methods to convert Java objects to JSON and vice-versa
• Allow pre-existing unmodifiable objects to be converted to and from JSON
• Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)

You can find more about google-gson here.

Hibernate-ORM is an object-relational mapper. It’s used for persisting data in relational databases. It provides an easier and more abstract way of doing that for the developers. It uses JDBC in its implementation. Hibernate is also an implementation of the JPA (Java Persistence API) specification.

Hibernate supports lazy initialization, numerous fetching strategies, and optimistic locking with automatic versioning and time stamping. Hibernate requires no special database tables or fields and generates much of the SQL at system initialization time instead of at runtime.

Hibernate consistently offers superior performance over straight JDBC code, both in terms of developer productivity and runtime performance.

Do you think that JPA can replace the original Hibernate? — comment your thoughts below in the comments/response section.

You can find more about Hibernate ORM here.

It’s the next generation of JUnit. This includes focusing on Java 8 and above, as well as enabling many different styles of testing.

JUnit is a free Java framework for writing unit tests. It provides functionality for conducting repeatable tests on your code. You just need to be careful not to get obsessed with the numbers (% code coverage). Bigger code coverage does not always mean better and bug-less code.

You can use sonarqube to measure estimated code coverage by writing the test cases using JUnit. (Below article contains how to set up sonarqube for your angular and java projects.)

You can find more about JUnit here.

Despite the name, Mockito is not an alcohol-free mixed drink but instead a mocking framework. Hope some pickup lines may put more interest while reading the articles.

However, Mockito enables you to create mocks and write tests easier with simpler and cleaner code. What I felt while exploring JUnit is that “Writing great tests has never been easier! But using Mockito — it made my life tasty!”

It will also provide you better readability while writing test cases and also produces clean verification errors, so you never lose track while finding any anonymous errors.

You can find more about Mockito here.

The two of these are both logging frameworks. Slf4j represents an abstraction for other logging frameworks (such as Log4j ). On the other hand, Log4j is just a simple logging framework. The latest version of Log4j is Log4j2, and it has awesome features to reduce your code load.

Do you know what you can do with these two library frameworks?

• You can log your methods executions in external files, It will help you with reviewing/debugging the errors — Real-time Productions logs are much important to track issues.
• You can send email notifications through the log4j2.xml file itself.
• You can format your logs, error, info, warning, debug, etc. log levels.

You can find more about Log4j here and Slf4j here.

How can we forget the base of java, the standard libraries? They are also used by millions of developers worldwide. Lots of people underestimate the core libraries or maybe because of lacking knowledge with such libraries they never use it!

Let me put some light on major libraries:

• Use java.util, you can find all the collections and data structures available in Java
• Use java.math provides functionality for working with arbitrary-precision decimal (BigDecimal) and integer (BigInteger) values
• Use java.lang, it is always implicitly being imported as it contains everything you basically cannot program without String, Double, Enum, Math, etc.
• Use java.net, it is being used for working with sockets, creating connections, or in short — creating networking applications
• In Java we also have libraries for working with GUI : javax.swing (extension of the older java.awt)
• We even can play music and create MIDI (Musical Instrument Digital Interface) files with java.sound
• Use java.io, for reading files, working with pipes, Internal Memory Buffer Access, Inter-Thread Communication (Pipes), Buffering, Filtering, streams, and Network access.
• Use java.nio, which actually is the alternative to java.io and stands for non-blocking I/O. It allows intensive use of the input/output operations as you might guess.

You can find more about the Java Standard library here.

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References: Research and R&D from below documents/communities/websites.
Apache commons, Apache logging, Angulario official documents, Jhipster official website, Google Gson, Apache maven, oracle official documents, Junit Mockito official community and spring io documents.