Development of REST API in Java

An API is a programming interface that makes it possible to use one web application inside another. For example, using this technology, an airline can send information about upcoming flights and their cost to partner sites, and the payment systems API allows you to accept payments on any site.

REST stands for Representational State Transfer. It is an architectural style that is one of the methods for creating APIs using the HTTP protocol. Today, the REST API is used in many large projects, including Google, Amazon and Twitter, and in most cases is the preferred technology due to its low bandwidth.

REST API can be developed in many different programming languages, including Java, Javascript, and Python, but must adhere to six basic REST design principles, which are also known as architectural constraints:

• Separation between client and server. The client is the user interface of a web application, such as a search bar on a website. In REST API technology, the request code always remains on the client side, while the code for accessing information, on the contrary, remains on the server side. This approach greatly simplifies the development of the API, makes it possible to transfer the user interface, and opens up great opportunities for scaling.
• Single interface. Requesting data from the server via a single URL must be done using standard protocols such as HTTP. This makes interaction with the server more transparent and secure, and also simplifies the site architecture.

• No record status. REST APIs are stateless and cannot store any data associated with a client request. Therefore, each new request to the server must contain comprehensive information necessary for its processing, regardless of the history of previous requests.
• Multilevel system. Client and server applications may not interact directly, but through various intermediaries, so REST APIs must be created in such a way that neither the client nor the server can know whether they work with each other directly or not.
• Caching. The request to the server should contain information about whether it is allowed to store data in the frequent request buffer. If so, the client will be able to use the cache when needed. The main idea is to improve the performance of processes.

The REST API is based on HTTP, the standard protocol used to carry most web traffic. To interact with objects on the server, the REST API uses four HTTP methods:

• GET – getting data about an object;

• POST – adding new information or updating existing data;
• DELETE – delete data;
• PUT – regular replacement or updating of data on the server;
• PATCH – partial data update.

Java is a high-level, object-oriented, robust, and secure programming language that has enjoyed high popularity for over 20 years. According to some reports, at the beginning of 2022, the language community exceeded 12 million programmers worldwide.

There are several reasons why you should use the Java programming language in your projects:

• A large set of free tools – frameworks, libraries, etc., which greatly speeds up the production process.
• Backward Compatibility – Java guarantees the stability of all software products written in earlier versions of the language.

• Multithreading – software written in Java can perform several tasks at the same time, which increases the functionality of the software.
• Code written in Java is cross-platform, and can be compiled on different operating systems – Windows, Linux and MacOS, without any additional modifications.
• Java is completely free.

In addition, the Java language has its own specification for developing APIs with a REST architectural pattern called JAX-RS, which greatly speeds up the process of creating programming interfaces.

The development of REST API can be divided into 5 main stages. Let’s consider each of them in more detail:

• Definition of resources. First of all, the developer sets the resources with which the API will work, after which their hierarchy is established.
• Definition of endpoints. They will depend on what actions the user can perform using the API – make payments, book tickets, etc.

• Select the data exchange format. For REST APIs, this is most often JSON.
• Development of successful responses. How exactly the API will respond to client requests in cases where no errors occur.
• Create responses to errors. Sometimes not everything goes according to plan, so developers need to anticipate how the API will work in the event of unforeseen problems.

REST API development in AVADA-MEDIA can be carried out in different programming languages, depending on the needs of a particular project. Our stack includes not only Java, but also Python, JavaScript and many other technologies. If you have any questions about creating software interfaces for your business, please contact us by filling out the feedback form.