Mulesoft, the Anypoint Platform execution engine, is a lightweight Java-based business services bus (ESB) and an integration platform that facilitates developers to attach applications quickly and easily, allowing them to replace data. It permits easy integration of already present systems, regardless of the various technologies utilized by the applications, consisting of JMS, web services, JDBC, HTTP and many more. The ESB can be position anywhere, can incorporate and arrange events in real time or groups, and has universal connections. The Mulesoft development offers various features required by the majority of companies.
The significant benefits of an ESB are that it permits various applications to converse with everyone by acting as a transportation system to transfer data between applications within a particular company or via the Internet.
Mule has powerful abilities that include:
- Creation and hosting of services: expose and host reusable services, with the ESB as a container of light services
- Service mediation: protect services from message formats and protocols, separate business logic from messages, and enable service calls independent of location
- Message routing: routing, filtering, adding and reordering messages according to content and rules
- Data transformation: exchange data through various formats and transport protocols.
Design and Development Tools:
- Anypoint Studio: a graphic development environment based on Eclipse to design, test and execute Mule flows. It contains two types of editors for development: visual editor and an XML editor.
- Any point Enterprise Security: a set of functions related to security for secure access and transactions to Mule applications.
- Mule Healthcare Toolkit: provided to process standard HL7 messages utilize in healthcare organizations.
- Mule IDE (now disused): -a set of Eclipse add-ons to develop, implement and manage Mule projects.
Mule is lightweight but extremely expandable, allowing people to begin small and connect many applications over time. The ESB direct all interactions among applications and components transparently, in spite of whether they are present in a similar virtual machine or via the Internet, and independently of the underlying transport protocol used.
Mule offers many advantages over competitors, including:
- Mule components can be of the type a company wants. People can effortlessly integrate anything from an "old and unformatted Java object" (POJO) to an element from another framework.
- Mule and the ESB model allow significant reuse of the components. Just like other frames, Mule enables the company to utilize its existing components without any significant modifications. The elements do not need any particular Mule code to run on Mule, and a programmatic API is not compulsory. The business logic remains completely disconnect from the messaging logic.
- Messages can be in any layout or format, from SOAP to binary image files. Mule does not compel any design restrictions on the architect, like XML messaging or WSDL service contracts.
- The company can implement Mule in a multiple of topologies, not just in ESB. Because it is lightweight and integrable, Mule can dramatically reduce time to marketplace and enhance project productivity to offer secure and expandable applications that adapt to modify and can scale as required.
Expressions used in Mule
MEL (Mule Expression Language) is the most commonly used expression language in Mule. The mule expressions that are a part of the language are designed to provide developers with a standardized way to work with the variables, properties, and payload of Mule. One of the biggest benefits that this expression language offers is the ease of use. And the biggest reason for this is the language uses context objects that are specific to Mule.
The language’s expressions used in Mule are simple. This, in turn, makes it easy for developers to dynamically test their applications without any technical hassle. MEL, in itself, is an expression evaluator that can also be considered as default. As such, the expression language helps maintain consistency when developers access information on the message. Actions taken by the message processor of Mule, including filtering and routing are seamless and accurate. This is because the expressions included in MEL work in sync with the message processor.
However, it is important to know that MEL hasn’t always been the go-to expression language for Mule. During the early versions of Mule, using evaluator-based syntax was one of the common ways on how to write expressions in Mule. Not only was this approach prone to errors but also was highly time-consuming. Apart from that, learning to precisely use these types of syntax would be time-consuming for developers.
MEL expressions are now written according to the following format:
If you are a beginner and don't know anything about MEL, learning the expression language isn't difficult at all. On the other hand, if you have a basic or high-level of understanding of Java, MEL-based Mule learning becomes highly easy for you. But regardless of whether you are a beginner or are competent in Java, it's important to follow a structured learning approach in order to get a strong grasp of the platform as well as the expression language.
One of the tried and true ways on how to learn Mule and MEL to first understand how the messaging structure of Mule works. This will work wonders in helping you develop a strong foundation of understanding which, in turn, boosts your understanding of MEL in the specific context of Mule. In a simple context, Mule message is a data form that uses one or more flows to pass through an application. The data form has different variables and properties which can be manipulated. You can get a good understanding of Mule message over here.
Learning Mule machine language, including the expression language MEL, gets easier if you build a strong foundation of message understanding. By developing proficiency and understanding the type of data included in the message, it becomes easier for you as a developer to make articulated and informed decisions. After you are done building a good understanding of the basics of Mule as well as MEL, you can then proceed to learn the basics syntax of Mule Expression Language. This document will make it easy for you to simplify your learning on MEL basic syntax.