Why Java Web Services Are Considered As A Smart Choice?

Java web servicesare server and client applications that communicate over HyperText Transfer Protocol (HTTP), providing a standard means for interoperating between different software applications that are running on a wide variety of frameworks and platforms. The components render a set of operations within a said application for use by a connecting third party application. Web services are characterized by their key extensibility and interoperability features, as well as descriptions that can be machine processed; thanks to their use of XML. Web services can be loosely coupled to help achieve complex operations, while programs offering simple services can seamlessly interact with each other to render value-added services.   

Types of Java Web Services

Typically, there are two types of web services – “Big” web services and “RESTful” web services. These are discussed in details herewith:

“Big” Web Services

In Java EE6, the functionality of “Big” web services is provided by JAX-WS. It uses XML messages that follow the Simple Object Access Protocol or SOAP standard. SOAP is an XML language that defines a message format and architecture. Big web services often contain machine-readable descriptions of different operations offered by the service, and written in the Web Services Description Language or WSDL, an XML language that defines interfaces syntactically.

Of late, the SOAP message format and WSDL interface definition language have gained much popularity. There are many development tools like NetBeans IDE that can minimize the complexity of building web service applications. SOAP-based web services much incorporate the following elements:

The architecture should address the non-functional and complex requirements. Several web service specifications address such requirements, and establish a single vocabulary for them. For instance, transactions, addressing, security, coordination, trust, etc.

It is crucial to establish a formal contract to describe the interfaces the web service offers. Here, WSDL can be used for describing the details of the contract, which may include operations, messages, location, and bindings of the web service. SOAP messages can also be processed in JAX-WS service without the need to publish WSDL.

The architecture must efficiently handle asynchronous invocation and processing. In this case, the infrastructure such as Web Services Reliable Messaging and APIs such as JAX-WS, with client-side asynchronous invocation support, can be easily leveraged in a unique way.

 RESTful Web Services

In Java, JAX-RS offers the functionality for Representational State Transfer or RESTful web services. REST is the ideal option for ad hoc and basic integration scenarios. Therefore, RESTful web services are better integrated with HTTP as compared to SOAP-based services, and do not require WSDL service, XML messages or API definitions.

RESTful web services use well-established W3C and Internet Engineering Task Force (IETF) standards such as HTTP, URI, XML and MIME. Additionally, they have a lightweight infrastructure that facilitates services to be designed with minimalist tooling. All these features make developing RESTful web services cost-efficient, and therefore, they have a very low barrier to adoption. One can also use a development tool like NetBeans IDE to further minimize the complexity to build RESTful web services.

A successfully built RESTfulJava web servicesmay have the following conditions met:

• It is a caching infrastructure that can be efficiently leveraged for performance. In scenarios where the data returned by the web service is not generated dynamically and can be cached, the infrastructure can be leveraged to enhance performance.

• Web services are stateless. It is important for developers to consider whether such interaction can seamlessly survive restart of the server.

• In RESTful web services, bandwidth is key, and needs to be limited.

• The service consumer and service producer should have a mutual understanding of the content and context being passed along.

The functioning of Java web servicesis based on the notion that the key functionalities of one application can be exposed easily to another client application, irrespective of what language is used and how it will use data.