Over a million developers have joined DZone.

MuleSoft: Payload Annotation Usage in Java Component

DZone's Guide to

MuleSoft: Payload Annotation Usage in Java Component

Learn about how to retrieve the JSON payload in the Java component using the @Payload annotation, which controls how a message payload is passed.

· Integration Zone
Free Resource

Modernize your application architectures with microservices and APIs with best practices from this free virtual summit series. Brought to you in partnership with CA Technologies.

@Payload annotation controls how the current message payload is passed into a method by performing automatic transformation of the message payload to match the annotated parameter type. A parameter injection annotation that can be used on component entry points.

The primary goal of this article is to retrieve the JSON payload in the Java component using the@Payload annotation.

I created a Book POJO class under src/main/java.

package com.ss.component;

public class Book {

 private String title;
 private String author;
 private double price;

 public String getTitle() {
  return title;
 public void setTitle(String title) {
  this.title = title;
 public String getAuthor() {
  return author;
 public void setAuthor(String author) {
  this.author = author;
 public double getPrice() {
  return price;
 public void setPrice(double price) {
  this.price = price;
 public String toString() {
  return "Book [title=" + title + ", author=" + author + ", price=" + price + "]";

...and a component class as:

package com.ss.component;

import org.mule.api.annotations.param.Payload;

public class MyComponent {
 public Object process(@Payload Book book) {
  System.out.println("Title:" + book.getTitle());
  System.out.println("Author:" + book.getAuthor());
  System.out.println("Price:" + book.getPrice());

  return book;

Develop the flow as follows:

<?xml version="1.0" encoding="UTF-8"?>
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/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd">
	<http:listener-config name="HTTP_Listener_Configuration" host="localhost" port="9001" doc:name="HTTP Listener Configuration"/>
	<flow name="component_annotationFlow">
		<http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP" allowedMethods="POST"/>
		<json:json-to-object-transformer returnClass="com.ss.component.Book" doc:name="JSON to Object"/>
		<component doc:name="Java">
			<singleton-object class="com.ss.component.MyComponent"/>
		<object-to-string-transformer doc:name="Object to String"/>
		<logger message="#[payload]" level="INFO" doc:name="Logger"/>

And here's the flow diagram:Image title

Run and deploy the flow to Anypoint runtime.

Test the flow with the POSTMAN plug-in:

Image title

Hit the HTTP URL with a POST request with a JSON body as:

        "title": "programming in c",
        "author": "bala guru swamy",
        "price": "100"

We can observe output in the console as:

  • Titleprogramming in c. 

  • Authorbala guru swamy. 

  • Price100.

INFO 2017-03-24 16:30:11,640:

[[component_annotation].HTTP_Listener_Configuration.worker .01]
org.mule.api.processor.LoggerMessageProcessor: Book[title = programming in c, author = bala guru swamy, price = 100.0]

Now, we have accessed the JSON payload in a Java component. 

The Integration Zone is proudly sponsored by CA Technologies. Learn from expert microservices and API presentations at the Modernizing Application Architectures Virtual Summit Series.

mulesoft ,tutorial ,payload annotation ,integration ,json

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}