Explanation of what Java API is ❓ Types. Examples

When the two most viable and essential application/software development comes together, programmers are allowed to have unmatched functionality. Java API (Application Programming Interface) is the perfect example of how to attain this. Acknowledged as a crucial entity for internal and open development, it is an expedient way to achieve flawless development.

What is Java?

It is unarguably one of the most globally recognized and widely-used object-oriented (OO) programming languages granting the least possible implementation-related dependencies. It’s famous in the developer’s community due to its WORA concept, meaning Write Once and Run Anywhere model.

With Java, developers need to invest efforts only once and use the existing code infinite times. Its congeniality with all the commonly used e-devices comes from JVMs or Java Virtual Machines.

It stands second to none when adaptability is considered as it automatically adapts as per the nature of hosting OS.

API in Java

API in Java is delivered via Java Development Kit or JDK. JDK is made up of three entities.

  1. Java compiler: A pre-quoted program used for breaking the complex user-written codes into simple and computer-understandable codes, known as byte-code.
  2. Java Virtual Machine (JVM): Allotted to process the byte code and generate an easy-to-understand output.
  3. Java API: The pre-integrated software components used for establishing a communication between desired software/platforms/components.

Java brings multiple pre-designed components into action for accomplishing the development process. Its API connects to included components and enable programmers to use their functionality so that they can make most of them.

Developers can refer to the classes and packages of available APIs and speed up the process of explaining the classes and packages for the planned program.

The Importance of Using APIs in Java

API is more than any other ordinary entity. It’s a way to make development smooth and enhance the development experience. Here is what significance API holds in Java.

  • API in Java makes key operational techniques and processes streamlined than ever. The live example of this is The Develop Social Intelligent Inbox. By simply login on to this platform, using Facebook and Twitter, allows one to pay attention to the messages, revert to the tagged posts, and operate on the search items. As the platform is developed using Java API, all these details are presented in a unified view saving time and effort.
  • Use of API in Java grants access to a wide range of SQL support.
  • Java API brings customization of high quality accessible for developers.

The Java REST API work

REST API is one of the most widely used API in Java, along with Web API, Java Help, Facebook.4J, and Twitter.4J. It makes code available and usable for every related application/program. While one is using REST API in Java, the basic rules to be followed are:

  • Stateless: REST follows client-server architecture to remain state-independent.
  • Uniform interface: Applications using REST API in Java and beyond will be requiring the undeviating client and server interface via HTTP and URIs
  • Client-server: Client and servers, involved in the communication, are independent of each other.
  • Cache: Cache is an imperative part of REST API in Java as its presence makes recording intermediate responses easier than ever.
  • Layered: REST API features layered structure and each layer is independent.

Types of Java APIs

The five acceptable types of Java API are explained next:

  1. Public Java APIs are often referred to as open Java API as they are part of JDK and don’t need any extra payment. Also, they are free from the areas and use cases of their implementation.
  2. Private or internal Java API is designed by a particular developer/organization and is accessible only to authorized professionals.
  3. Partner Java APIs are the third-party APIs offered to businesses for specific operations.
  4. Composite Java API is basically microservices developed using clubbing different kinds of APIs.
  5. Web Java API is accessed via HTTP protocol and is used to establish a communication bridge for browser-based applications/services like web storage and web notifications.

Java API example

APIs in Java can be custom as well as open-source packages. For the APIs your developer or a service provider has created, you will have to learn relevant functions and get to know how to fetch data or perform functions through it. However, Java’s own API have detailed descriptions and guidance available on Oracle’s official website and throughout the internet.

Let’s take the example of JDBC API. It is the API that lets you access your project’s database and fetch data using various legit queries. It has 2 packages, namely — java.sql and javax.sql.

To use the classes in these packages in your code, you must first import these in the beginning of your file. For this, the code will be:

import java.sql.*
import javax.sql.*

If you want to use a few specific classes from any of these APIs, you can perform the import using following function:

import java.sql.Connection;
import java.sql.SQLException;

In above example, imported classes are SQLException and Connection. These both belong to java.sql package of JDBC API.

Here is an example code that uses data received using the Java JDBC API:

public static void commit() {	
Connection chk_con = this.get();
if (chk_con != null) {
try {
} catch (SQLException e) {
throw new RuntimeException("Transaction related exception occurred when tried to establish a connection…");

Advantages of API in Java

The direct impact of using API in Java is expedient the development as it makes pre-defined classes and packages available for intended programs. However, that’s not the only advantage. There are many more, such as:

  • Java APIs keep human involvement as least as possible and empower computers so much that they take care of the entire development job. Java API deploys automaton of highest grade into action and makes crucial workflow quick and error-free.
  • Service delivery is much more flexible with Java APIs as these APIs are available for every component and lift all the data access restrictions. Additionally, the content or code generated using Java API is set to be released and work. All the related channels are allowed to access this freshly-generated content. This makes development quick from the ground level.
  • Java APIs exhibit unmatched integration abilities as they are ready-to-be-embedded in any software/program/website. The high-end integration makes data fluid enough to be used at any platform wherever enhanced user-experience goal fulfillment demands.

Securing APIs in Java

APIs, lacking security, bear high risks for the developed applications. This is why developers are allowed to adopt key API security practices without any compromise. There are several frameworks for this job. For instance, if REST API is used in Java then Apache Shiro is a great choice to make.
Using this framework, one can easily execute API token security of your choice. Java EE and Spring offer a robust security framework for Java API. However, one has to make tedious efforts to bring these frameworks into action to reap the benefits. This is why Wallarm is the most preferred choice. It endows developers with tailored-made API security solutions that can protect all sorts of Java API, regardless of the nature of OS.

Originally published at https://www.wallarm.com.



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Ivan Novikov

CEO at Wallarm. Application security platform to prevent threats and discover vulnerabilities in a real-time.