Java, a versatile and robust programming language, continues to be a cornerstone of the software development landscape. With an ever-expanding ecosystem of libraries, developers can leverage powerful tools to streamline their workflow, enhance code quality, and build scalable and efficient applications.
In this blog post, we will explore the top 10 Java libraries that are essential for developers to know. These libraries can be used to perform a variety of useful tasks and are utilized by the finest Java developers.
Top 10 Java Libraries You Must Know
Staying updated with the latest Java libraries is crucial for developers to stay competitive and build efficient, scalable, and maintainable applications.
The libraries mentioned below cover a wide range of functionalities, from web development to data processing, making them essential tools in the modern Java developer’s toolkit.
1. Logging Libraries
This is a very common type of Java library, as one needs them in almost every project. Logging libraries are crucial for server-side applications because the logs are placed in locations where one can precisely see what is happening in the application.
There are certainly better alternatives available, even though the JDK has its own logging library. But, most importantly, every Java developer should be aware of the pros and cons of logging libraries.
2. JSON Parsing libraries
JSON parsing has undoubtedly become the go-to protocol in this 21st century of IoT and web services, carrying information from the client to the server. XML has been replaced as the most preferred way to transform information in a platform-independent manner. However, it is unfortunate that a JSON library is not included in the JDK.
Though there are many good third-party libraries, a Java developer should know at least one of these libraries that allows them to parse and create JSON messages.
Unfortunately, a JSON library is not included in the JDK. However, there are many good third-party libraries, and a Java developer should be familiar with at least one of these libraries that allows them to parse and create JSON messages.
3. Unit Testing Libraries
The one most important thing that separates an average developer from a good developer is the knowledge of unit testing libraries. Unit testing is essentially a process or a method of testing a piece of code, which is the smallest unit in a system that can be logically isolated. A unit is the smallest testable part of any software that has a single output or one or more inputs.
To make the software perform according to one’s desires, it is important to validate each unit. Programmers often give many excuses to avoid writing unit tests, with the most common one being the lack of knowledge and experience with popular unit testing libraries, including PowerMock, JUnit, and Mockito.
4. General-Purpose Libraries
Many Java libraries simplify numerous tasks, including general-purpose or third-party libraries available to Java developers, such as Google Guava and Apache Commons.
In “Effective Java,” Joshua Bloch emphasizes the importance of preferring tried and tested libraries over creating routines repeatedly, as there is no point in reinventing the wheel. Therefore, it is an excellent opportunity for a Java developer to become familiar with the Apache Commons library and the Google Guava library.
5. HTTP Libraries
If there is one drawback of the JDK, it is the lack of support for HTTP. Although the java.net package can establish an HTTP connection using classes, it is not as seamless or user-friendly as open-source third-party libraries like HttpCore Apache and HttpClient.
Every Java developer should strongly consider becoming familiar with HTTP client libraries, including HttpCore and HttpClient, as JDK 9 is bringing better support for HTTP and also providing support for HTTP 2.0.
6. XML Parsing Libraries
XML Parsing Libraries consist of a lightweight set of reusable functions designed for the general purpose of checking, parsing, and creating XML files. It supports SAX or DOM parsing styles and can handle stream orientation. Additionally, they include an optional graphical schema generator and XSD schema validator.
There are numerous XML parsing libraries, including Xstream, Xerces, Dom4j, JAXB, and JAXP. In the Apache Xerces family, Xerces2 represents the next generation of fully compliant XML parsers, offering high performance.
This new version introduces a framework designed for building parser components and configurations that are extremely easy to program and highly modular, known as the Xerces Native Interface (XNI). XNI serves as the reference implementation of the Apache Xerces2 parser.
7. Excel Reading Libraries
The Excel Reading Library is a robust tool that facilitates both writing and reading XLS files from a Java program. In the realm of real-world applications, interaction with Microsoft Office is inevitable.
Excel is among the essential components required for the operation of many applications. It is necessary to incorporate the functionality to export data in Excel, and for this purpose, the Apache POI API becomes crucial when performing the same task within a Java application.
8. Bytecode Libraries
It enables Java programs to modify a class file and define a new class at runtime before the JVM loads it. One needs a bytecode library when interacting with bytecode or when writing a framework or libraries that generate code, eventually allowing the modification and reading of bytecode generated by an application. Javassist and Cglib Nodep are among the popular bytecode libraries in the world of Java.
Java bytecode manipulation becomes straightforward thanks to Javassist (JAVA programming ASSISTant), making it one of the best libraries for editing bytecode in Java. Another useful bytecode editing library is ASM.
9. Database Connection Pool Libraries
It feels like something is missing if one is not using a database connection pool library while interacting with the database from a Java application. It is advisable to use database connection libraries, as creating a database connection at runtime makes the requesting process slower and also consumes a significant amount of time. Pool and DBCP are among the popular ones.
While a web server typically provides this functionality in a web application, a database connection pool library is necessary when working in a Java application. To effectively use the database connection pool, one needs to include all these connection pool libraries.
10. Messaging Libraries
Messaging is also an intrinsic characteristic of many real-world Java applications, akin to database connection and logging. Java provides JMS or the Java Messaging Service. It is not part of the JDK; for this, one needs a separate JMS.jar, which is provided by Java.
Similarly, if one is using Tibco RV, a third-party messaging protocol, then one needs to include the third-party JAR in the application classpath.
Conclusion
Every Java developer needs to know the field of Java libraries, as every Java application requires these libraries. Though there are many more libraries of this kind, the ones mentioned here are among the top and best Java libraries to make applications easier.
