Define the domain class Employee.
package com.javainuse.model;
public class Employee {
private int empId;
private String name;
private String designation;
private double salary;
public Employee() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDesignation() {
return designation;
}
public void setDesignation(String designation) {
this.designation = designation;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public int getEmpId() {
return empId;
}
public void setEmpId(int empId) {
this.empId = empId;
}
}
Expose the service using the Controller. We will be exposing 2 API's here-
-
The GET API will accept an id as a request parameter and create an employee object using the passed id and return it as response.
-
The POST API will accept an employee object as request body. Using the parameters of the employee object it will create another employee
object and return it as response.
package com.javainuse.controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import com.javainuse.model.Employee;
@RestController
public class TestController {
@RequestMapping(value = "/employee", method = RequestMethod.GET)
public Employee firstService(@RequestParam int id) {
Employee emp = new Employee();
emp.setName("emp1");
emp.setDesignation("manager");
emp.setEmpId(id);
emp.setSalary(3000);
return emp;
}
@RequestMapping(value = "/employee", method = RequestMethod.POST)
public Employee secondService(@RequestBody Employee employee) {
System.out.println("Inside POST Method");
Employee emp = new Employee();
emp.setName(employee.getName());
emp.setDesignation(employee.getDesignation());
emp.setEmpId(employee.getEmpId());
emp.setSalary(employee.getSalary());
return emp;
}
}
Finally define the Spring Boot Main class
package com.javainuse;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringBootHelloWorldApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootHelloWorldApplication.class, args);
}
}
Apache Camel Module for consuming REST API's
The project structure we would be creating will be as follows-
The pom.xml will be as follows-
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.javainuse</groupId>
<artifactId>apache-camel-consume</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-spring</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-http</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jackson</artifactId>
<version>2.12.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
</plugin>
</plugins>
</build>
</project>
Define the domain class Employee.
package com.javainuse.model;
public class Employee {
private int empId;
private String name;
private String designation;
private double salary;
public Employee() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDesignation() {
return designation;
}
public void setDesignation(String designation) {
this.designation = designation;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public int getEmpId() {
return empId;
}
public void setEmpId(int empId) {
this.empId = empId;
}
}
Create the camel processor which will create an Employee object and then marshal it to JSON. This will be required
for POST call-
package com.javainuse.processor;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import com.javainuse.model.Employee;
public class CreateEmployeeProcessor implements Processor {
public void process(Exchange exchange) throws Exception {
System.out.println(exchange.getIn().getBody(String.class));
Employee emp = new Employee();
emp.setName("camel-employee");
emp.setDesignation("camel-manager");
emp.setEmpId(111);
emp.setSalary(30000);
exchange.getIn().setBody(emp);
}
}
Create the SimpleRouteBuilder class that extends
RouteBuilder and configures the camel route.
package com.javainuse.route;
import org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.jackson.JacksonDataFormat;
import com.javainuse.model.Employee;
import com.javainuse.processor.CreateEmployeeProcessor;
import com.javainuse.processor.MyProcessor;
public class SimpleRouteBuilder extends RouteBuilder {
JacksonDataFormat jsonDataFormat = new JacksonDataFormat(Employee.class);
@Override
public void configure() throws Exception {
// route for REST GET Call
from("file:C:/inputFolderREST?noop=true").setHeader(Exchange.HTTP_METHOD, simple("GET"))
.to("http://localhost:8080/employee?id=5").process(new MyProcessor());
// route for REST POST Call
from("file:C:/inboxPOST?noop=true").process(new CreateEmployeeProcessor()).marshal(jsonDataFormat)
.setHeader(Exchange.HTTP_METHOD, simple("POST"))
.setHeader(Exchange.CONTENT_TYPE, constant("application/json")).to("http://localhost:8080/employee")
.process(new MyProcessor());
}
}
Create the camel processor which will be printing the response returned after consuming the REST API
package com.javainuse.processor;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
public class MyProcessor implements Processor {
public void process(Exchange exchange) throws Exception {
System.out.println(exchange.getIn().getBody(String.class));
}
}
Create the application context that calls the Java DSL RouteBuilder
class using the routeBuilder
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://camel.apache.org/schema/spring
http://camel.apache.org/schema/spring/camel-spring.xsd">
<bean id="routeBuilder" class="com.javainuse.route.SimpleRouteBuilder" />
<bean id="processor" class="com.javainuse.processor.MyProcessor" />
<camelContext xmlns="http://camel.apache.org/schema/spring">
<routeBuilder ref="routeBuilder" />
</camelContext>
</beans>
Finally load the context file to start the Java DSL camel route.
package com.javainuse.main;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApp {
public static void main(String[] args) {
AbstractApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-camel.xml");
ctx.start();
System.out.println("Application context started");
try {
Thread.sleep(5 * 60 * 1000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
ctx.stop();
ctx.close();
}
}
-
Start the Spring Boot Module which exposes the REST API.
-
Start the Apache Camel Module-
Copy some data in C:/inputFolderREST folder. The REST GET API consumption route gets triggered
Copy some data in C:/inputFolderPOST folder. The REST POST API consumption route gets triggered
Download Source Code
Download it -
Apache Camel Consume REST API Module
Download it -
Spring Boot Expose REST API Module
See Also
Spring Boot Hello World Application- Create simple controller and jsp view using Maven
Spring Boot Tutorial-Spring Data JPA
Spring Boot + Simple Security Configuration
Pagination using Spring Boot Simple Example
Spring Boot + ActiveMQ Hello world Example
Spring Boot + Swagger Example Hello World Example
Spring Boot + Swagger- Understanding the various Swagger Annotations
Spring Boot Main Menu
Spring Boot Interview Questions
