The document discusses how to use a REST component in Mule applications to perform arithmetic operations like addition, subtraction and multiplication. It provides an example Mule flow configuration that defines a REST endpoint and component class that handles the different arithmetic operations. The component class is annotated with JAX-RS annotations to define the REST resources. The example also shows how to test the REST services by triggering requests to the defined endpoints and paths.

1. How to use REST Component
15-12-2014

2. Abstract
• The main motto of this PPT is How to use REST
Component in our applications.

3. Introduction
• REST stands for Representational State
Transfer. REST exposes a much simpler
interface than SOAP. REST components are
bound with HTTP. So, if you are designing
an application to be used exclusively on the
Web, REST is a very good option. RESTful
applications simply rely on the built-in HTTP
security. A REST design is good for database-
driven applications and also when a client
wants quick integration.

4. SOAP Component POC:
Link: https://youtu.be/h-aJIjt9TcQ
How to do above POC using REST component?

5. Example
ArthematicOperations
a. Addition
b. Subtraction
c. Multiplication

7. .mflow
<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:jersey="http://www.mulesoft.org/schema/mule/jersey"
xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns="http://www.mulesoft.org/schema/mule/core"
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
xmlns:spring="http://www.springframework.org/schema/beans" version="EE-3.4.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/jersey http://www.mulesoft.org/schema/mule/jersey/current/mule-jersey.xsd">
<flow name="RestComponentFlow1" doc:name="RestComponentFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8098" doc:name="HTTP"/>
<logger message="---Entered into the flow" level="INFO" doc:name="Logger"/>
<jersey:resources doc:name="REST">
<component class="com.ArthematicOperations"/>
</jersey:resources>
</flow>
</mule>

8. com.ArthematicOperations:
• package com;
• import javax.ws.rs.Consumes;
• import javax.ws.rs.POST;
• import javax.ws.rs.Path;
• import javax.ws.rs.Produces;
• import javax.ws.rs.core.MediaType;
• import org.codehaus.jackson.JsonNode;
• import org.codehaus.jettison.json.JSONObject;
• @Path("/")
• public class ArthematicOperations {
• @POST
• @Produces(MediaType.APPLICATION_JSON)
• @Consumes(MediaType.APPLICATION_JSON)
• @Path("Addition")
• public Object addition(JsonNode inputJSON) throws Exception {
• JSONObject jsonStatus = new JSONObject();
• jsonStatus.put("Result",(Integer.parseInt(inputJSON.get("Num1").getTextValue())+Integer.parseInt(inputJSON.get("Num2").getTextValue())));
• return jsonStatus.toString();
• }
• @POST
• @Consumes(MediaType.APPLICATION_JSON)
• @Produces(MediaType.APPLICATION_JSON)
• @Path("Subtraction")
• public Object subtraction(JsonNode inputJSON) throws Exception {JSONObject jsonStatus = new JSONObject();
• jsonStatus.put("Result",(Integer.parseInt(inputJSON.get("Num1").getTextValue())-Integer.parseInt(inputJSON.get("Num2").getTextValue())));
• return jsonStatus.toString();
• }
• @POST
• @Consumes(MediaType.APPLICATION_JSON)
• @Produces(MediaType.APPLICATION_JSON)
• @Path("Multiplication")
• public Object multiplication(JsonNode inputJSON) throws Exception {JSONObject jsonStatus = new JSONObject();
• jsonStatus.put("Result",(Integer.parseInt(inputJSON.get("Num1").getTextValue())*Integer.parseInt(inputJSON.get("Num2").getTextValue())));
• return jsonStatus.toString();
• }
• }

9. How to test this?
URLs
Addition: http://localhost:8098/Addition
Subtraction: http://localhost:8098/Subtraction
Multiplication:
http://localhost:8098/Multiplication

10. Trigger the methods:
1. Addition:

11. • Console:
INFO 2015-12-15 18:09:29,554 [main] org.mule.DefaultMuleContext:
**********************************************************************
* Application: RestComponent *
* OS encoding: Cp1252, Mule encoding: UTF-8 *
* *
* Agents Running: *
* Clustering Agent *
* JMX Agent *
**********************************************************************
INFO 2015-12-15 18:09:29,556 [main]
org.mule.module.launcher.MuleDeploymentService:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Started app 'RestComponent' +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
INFO 2015-12-15 18:10:28,825
[[RestComponent].connector.http.mule.default.receiver.02]
org.mule.api.processor.LoggerMessageProcessor: ---Entered into the flow

12. References
• https://docs.mulesoft.com/mule-user-
guide/v/3.7/rest-component-reference