Spring 4 + RESTEasy 3 + Jackson JSON Integration Example with Tomcat
March 14, 2015
Software Required to Run Example
To run the example, we are using following software.1. Java 7
2. Tomcat 8
3. Gradle
4. Eclipse
Project Structure in Eclipse
Find the project structure in eclipse which we are using in our example.
Gradle File for Spring Boot, RESTEasy JAR and Jackson Provider
Find the Gradle file to resolve dependencies of Spring, RESTEasy and Jackson provider.build.gradle
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'war'
archivesBaseName = 'resteasyservice'
version = '1'
repositories {
mavenCentral()
}
dependencies {
compile 'org.jboss.resteasy:resteasy-jaxrs:3.0.10.Final'
compile 'org.jboss.resteasy:resteasy-spring:3.0.10.Final'
compile 'org.springframework.boot:spring-boot-starter-web:1.2.2.RELEASE'
compile 'org.jboss.resteasy:resteasy-jackson2-provider:3.0.10.Final'
}
web.xml: Declare SpringContextLoaderListener after ResteasyBootstrap
RESTEasy provides SpringContextLoaderListener to integrate Spring. In web.xml, we need to declare SpringContextLoaderListener after ResteasyBootstrap.resteasy.servlet.mapping.prefix: Context parameter to assign prefix for URL mapping used by RESTEasy.
contextConfigLocation: Context parameter used by spring to find XML file.
org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap: ResteasyBootstrap initializes ServletContext.
org.jboss.resteasy.plugins.spring.SpringContextLoaderListener: RESTEasy provides SpringContextLoaderListener for spring integration which must be declared after ResteasyBootstrap because SpringContextLoaderListener uses ServletContext initialized by ResteasyBootstrap.
org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher: Dispatcher used by RESTEasy.
Find the web.xml file.
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<context-param>
<param-name>resteasy.servlet.mapping.prefix</param-name>
<param-value>/employee</param-value>
</context-param>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
</context-param>
<listener>
<listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
</listener>
<listener>
<listener-class>org.jboss.resteasy.plugins.spring.SpringContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>RESTEasyService</servlet-name>
<servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.concretepage.EmployeeApplication</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>RESTEasyService</servlet-name>
<url-pattern>/employee/*</url-pattern>
</servlet-mapping>
</web-app>
Create Spring Bean
In our project we are creating a class to fetch employee. Find the employee repository interface.EmployeeRepository.java
package com.concretepage;
import java.util.Map;
public interface EmployeeRepository {
Map<String,String> getEmpDetail(String id);
}
EmployeeRepositoryImpl.java
package com.concretepage;
import java.util.HashMap;
import java.util.Map;
import org.springframework.stereotype.Service;
@Service
public class EmployeeRepositoryImpl implements EmployeeRepository {
@Override
public Map<String,String> getEmpDetail(String id){
Map<String,String> map = new HashMap<String,String>();
map.put("Id", id);
map.put("Name", "Arvind Rai");
map.put("Location", "Varanasi");
return map;
}
}
Spring XML
Find the spring XML.dispatcher-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
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-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.concretepage" />
</beans>
Create Web Service Class
We are creating a web service to fetch employee and for that we are creating a JAX-RS method. To get return type as JSON, we need to provide content type as application/json . RESTEasy will use Jackson provider to return JSON response. To be considered as Spring component, we need to annotate our web service class with spring @Component annotation. And in this way, we will be able to inject our spring service or bean in RESTEasy service class.EmployeeService.java
package com.concretepage;
import java.util.Map;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
@Path("/manage" )
@Component
public class EmployeeService {
@Autowired
private EmployeeRepository employeeRepository;
@GET
@Path("/{id}")
@Produces("application/json")
public Response getEmp(@PathParam("id") String id) {
Map<String,String> map = employeeRepository.getEmpDetail(id);
return Response.ok(map).build();
}
}
EmployeeApplication.java
package com.concretepage;
import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.core.Application;
public class EmployeeApplication extends Application {
private Set<Object> singletons = new HashSet<Object>();
public EmployeeApplication() {
singletons.add(new EmployeeService());
}
@Override
public Set<Object> getSingletons() {
return singletons;
}
}
Output
Run Gradle file to create WAR and deploy it into Tomcat 8 and access the URL ashttp://localhost:8080/resteasyservice-1/employee/manage/222
And we will get JSON response as
{"Name":"Arvind Rai","Location":"Varanasi","Id":"222"}
