RESTEasy hello world example

RESTEasy, JBoss project, implementation of the JAX-RS specification. In this tutorial, we show you how to use RESTEasy framework to create a simple REST style web application.

Technologies and Tools used in this article:

  1. RESTEasy 2.2.1.GA
  2. JDK 1.6
  3. Maven 3.0.3
  4. Eclipse 3.6
What’s REST?
Read this, this and this to understand what’s REST.

1. Directory Structure

Review final directory structure of this tutorial. Just a standard web project structure.

directory structure

2. Standard Web Project

Create a standard Maven web project structure.


mvn archetype:generate -DgroupId=com.mkyong.common -DartifactId=RESTfulExample 
	-DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false

Convert to Eclipse web project.


mvn eclipse:eclipse -Dwtpversion=2.0

3. Project Dependencies

Declares JBoss public Maven repository and “resteasy-jaxrs” in your Maven pom.xml file. That’s all you need to use RESTEasy.

File : pom.xml


<project ...">

	<repositories>
	   <repository>
		  <id>JBoss repository</id>
		  <url>https://repository.jboss.org/nexus/content/groups/public-jboss/</url>
	   </repository>
	</repositories>

	<dependencies>

		<dependency>
			<groupId>org.jboss.resteasy</groupId>
			<artifactId>resteasy-jaxrs</artifactId>
			<version>2.2.1.GA</version>
		</dependency>

	</dependencies>
</project>

4. REST Service

A simple REST service. See demo at the end of the article, it should be self-explanatory.


package com.mkyong.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Response;

@Path("/message")
public class MessageRestService {

	@GET
	@Path("/{param}")
	public Response printMessage(@PathParam("param") String msg) {

		String result = "Restful example : " + msg;

		return Response.status(200).entity(result).build();

	}

}

5. web.xml

Now, configure listener and servlet to support RESTEasy. Read this JBoss documentation for detail explanation.

File : web.xml


<web-app id="WebApp_ID" version="2.4"
	xmlns="http://java.sun.com/xml/ns/j2ee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
	http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
	<display-name>Restful Web Application</display-name>

	<!-- Auto scan REST service -->
	<context-param>
		<param-name>resteasy.scan</param-name>
		<param-value>true</param-value>
	</context-param>
	
	<!-- this need same with resteasy servlet url-pattern -->
	<context-param>
		<param-name>resteasy.servlet.mapping.prefix</param-name>
		<param-value>/rest</param-value>
	</context-param>

	<listener>
		<listener-class>
			org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap
		</listener-class>
	</listener>
	
	<servlet>
		<servlet-name>resteasy-servlet</servlet-name>
		<servlet-class>
			org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
		</servlet-class>
	</servlet>
     
	<servlet-mapping>
		<servlet-name>resteasy-servlet</servlet-name>
		<url-pattern>/rest/*</url-pattern>
	</servlet-mapping>

</web-app>
Note
You need to set the “resteasy.servlet.mapping.prefix” if your servlet-mapping for the resteasy servlet has a url-pattern other than “/*“.

In above example, the resteasy servlet url-pattern is “/rest/*“, so you have to set the “resteasy.servlet.mapping.prefix” to “/rest” as well, otherwise, you will hit resource not found error message.

Note
Remember to set “resteasy.scan” to true, so that RESTEasy will find and register your REST service automatically.

6. Demo

In this example, web request from “projectURL/rest/message/” will match to “MessageRestService“, and “projectURL/rest/message/{any values}” will match to @PathParam parameter.

Test 1 : http://localhost:8080/RESTfulExample/rest/message/mkyong

example 1

Test 2 : http://localhost:8080/RESTfulExample/rest/message/hello%20world

example 2

Alternative REST Service Registration

In above example, you are register REST service via “ResteasyBootstrap” listener. Here i show you another way.

Create a class and extends javax.ws.rs.core.Application, and add your REST service manually.


package com.mkyong.app;

import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.core.Application;
import com.mkyong.rest.MessageRestService;

public class MessageApplication extends Application {
	private Set<Object> singletons = new HashSet<Object>();

	public MessageApplication() {
		singletons.add(new MessageRestService());
	}

	@Override
	public Set<Object> getSingletons() {
		return singletons;
	}
}

File : web.xml , no more listener, configure your application class like below :


<web-app id="WebApp_ID" version="2.4"
	xmlns="http://java.sun.com/xml/ns/j2ee" 
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
	http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
	<display-name>Restful Web Application</display-name>

	<context-param>
		<param-name>resteasy.servlet.mapping.prefix</param-name>
		<param-value>/rest</param-value>
	</context-param>

	<servlet>
		<servlet-name>resteasy-servlet</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.mkyong.app.MessageApplication</param-value>
		</init-param>
	</servlet>

	<servlet-mapping>
		<servlet-name>resteasy-servlet</servlet-name>
		<url-pattern>/rest/*</url-pattern>
	</servlet-mapping>

</web-app>

Done.

Download Source Code

Download it – RESTEasy-Hello-World-Example.zip (7 KB)

References

  1. RESTEasy Framework
  2. RESTEasy installation and configuration
  3. IBM : RESTful Web services: The basics
  4. RESTful Web Services
  5. Wiki : Representational State Transfer

About the Author

author image
mkyong
Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

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avatar
newest oldest most voted
harikrishnan
Guest
harikrishnan

how do you given this url?? can you please explain….?
http://localhost:8080/RESTfulExample/rest/message/hello%20world

Luke
Guest
Luke

The second link in ‘What’s REST?’ is broken. The correct link is: https://www.ibm.com/developerworks/library/ws-restful/index.html

Watchut Awkin
Guest
Watchut Awkin
Thanks for this site. I have learnt a lot from here, both from mkyong and the other readers. I am still new to programming web services and would like to know why mvn generates FOUR projects, namely rest, ejb, rest-web & model.. Please advise which artifacts goes into each of these projects as everywhere I find examples on rest web services, I find everything in a single project and I am sure there has to be some reason for mvn to generate four separate projects… however, I am too less knowledge to figure it out.. and online searches gives me… Read more »
ThinkingInJava
Guest
ThinkingInJava

Thanks for the nice tutorial. Can you please publish a tutorial on the following?

RESTEasy + Spring Security 4.x + OAuth2

It will really be helpful if you can publish it as I did not find any blog/tutorial on this combination on Web.

karl
Guest
karl

Thanks mykong, I use your site all the time. You are great.

Ranjit Jadhav
Guest
Ranjit Jadhav

Hi all. I have created rest service but i am facing cross origin problem when i am trying to accessing through ajax call please help me to fix this

Shivangi Aneja
Guest
Shivangi Aneja

Hi..
I am trying to run this example using using Tomcat and Eclipse, but when server gets started Error 404 occurs.
Also when hit correct URL, then also 404 occurs..
No jar error in console…
Please help asap..
Its urgent………

Rich
Guest
Rich

What does it mean when you get a “404 not found” when you run the first demo “http://localhost:8080/RESTfulExample/rest/message/mkyong” ?

Shivangi Aneja
Guest
Shivangi Aneja

I am also facing the same issue..
Any idea how to solve it

Pramod Kumar
Guest
Pramod Kumar

It means,,,resource is not available for the particular URL on the server, which u r requesting.

AB
Guest
AB

great post. On TomEE if you make this war it works. If you copy the war and rename it re.war and deploy that as well. Only one of the sites produced works.
Why can’t two sites with restful services work?

vikash
Guest
vikash

How many ways we can bootstrap my Jax-RS runtime using Resteasy implementation.

markzona
Guest
markzona

Does not work for me in Wildfly 8.2.0.Final. The only thing I had to do was to add

an “activator” class, to not use a web.xml and no Maven dependencies were needed.

That’s all to get JaxRs running in Wildfly 8.2.0:

@ApplicationPath(“/rest”)
public class JaxRsActivator extends Application
{
}

Zhimeng Jin
Guest
Zhimeng Jin

For people using JBoss Wildfly 8.2.0.Final & Maven POM, due to the automatic deployment for RestEasy in JBoss Wildfly, the scope of RestEasy dependency in Maven POM needs to be set “Provided” to avoid module conflicts.

org.jboss.resteasy
resteasy-jaxrs
3.0.10.Final
provided

More info., please refer to this question: http://stackoverflow.com/questions/15603662/asynchronousdispatcher-error

Hope it helps!

Sandeep K Nair
Guest
Sandeep K Nair
Hi MKyong, Thank you for this awesome tutorial. I have a question. How can we redirect to a page when we hit this service urls (I am trying to develop an application which has services & a monitoring page for the services) For example lets say my URL is http://localhost:8080/TestApp/rest/monitor When i hit this URL i wanted the application to navigate to sample-monitor.jsp I tried the above approach using so, but i was not getting the page that i requested Service class: @Path(“/”) public class TestAppService{ @GET @Path(“/monitor”) public void getPage(){ try { HttpServletRequest req = ResteasyProviderFactory.getContextData(HttpServletRequest.class); HttpServletResponse res =… Read more »
Sandeep K Nair
Guest
Sandeep K Nair

Found the issue.

I had the following in my web.xml

resteasy.servlet.mapping.prefix
/

which intercepted all the request as a rest call.

i modified it as below, which makes rest call when url is prefixed with rest/* and ignores other requests (example request for any pages)

resteasy.servlet.mapping.prefix
/rest/*

which fixed my problem.

Hope this will be helpful for someone :)

Gio
Guest
Gio

Thank you so much. I have spent days trying to properly configure JBoss for Rest Services. I had the same problem with ResteasyBootstrap as Dilip, but alternative method worked well with a little tweaking. I had to manually install some jar libraries, change compiler version in pom, do mvn install on pom.xml, then run on JBoss 7.1. Thanks again.

Claudius Gothicus
Guest
Claudius Gothicus

Worked well :) On to tinkering with it.

Venkat
Guest
Venkat

Do you have steps for deploying rest service in weblogic 10.3 server. i have below code and need to deploy the same in weblogic server

package com.RS;
import javax.ws.rs.GET;
import javax.ws.rs.Produces;
import javax.ws.rs.Path;
@Path(“/TestHello”)
public class TestJAXRS_Hello {
@GET
@Produces(“text/html”)
public String getString(){
return “TEST JAX-RS”;
}
}

Appreciate your help

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[…] RESTEasy hello world example RESTEasy framework to create a simple REST style web application. […]

Shrestha
Guest
Shrestha
I am using Restful web service in eclipse. Few days ago it is running smoothly. But today, something goes wrong. Web services are running properly but when I modified something on web service program it does not reflect after invoking the web service. I have noticed earlier that whenever I changed small code in my program the server starts automatically and it reflects on the fly. Now my web service starts but seems like it runs from cache. Whatever I modified in the program it does not show in output. I have restart (stop & start) the server and even… Read more »
Anadi Kumar
Guest
Anadi Kumar

Hey folks,

you need the following jars:

A few of the above jars are not included in the .classpath file.

Regards,

Anadi Kumar
mail – anadikumar@gmail.com

Pavan
Guest
Pavan

Hello mkyong,

This is a nice and simple explanation. I appreciate it.

I have one question regarding the implementation. Is it possible to remove project name in the URL ? (RESTfulExample in your case) to make the URL simple by any means of configuration.

Thanks

Pavan

Smith Wilson
Guest
Smith Wilson

Yes, rename your project to ROOT, and done.

Sachin
Guest
Sachin

Hey
This is very nice tutorial ,But i need simple token base oAuth in my web service.I had rest easy web services running on tomcat.Can anyone suggest me how can i implement that.

Note – Suppose that oAuth in jboss as7 and web services on tomcat.

Thanks in advance.

http://mototai.ru/
Guest
http://mototai.ru/

Valuable info. Fortunate me I discovered your site by accident,
and I’m shocked why this coincidence didn’t happened in advance!
I bookmarked it.

comparecarinsurancee11.com
Guest
comparecarinsurancee11.com

Awesome! Its truly amazing post, I have got
much clear idea regarding from this post.

Ed
Guest
Ed

Great tutorial, but could use some info on packaging and running.

mvn package

and then to run it and test it quickly from the command line, I added the jetty plugin to the pom

RESTfulExample

org.mortbay.jetty
maven-jetty-plugin

then

mvn jetty:run-war

Thanks!

Ed
Guest
Ed

looks like the jetty plugin xml did not render…
I’ll try again:

RESTfulExample

org.mortbay.jetty
maven-jetty-plugin

Ed
Guest
Ed

Still didn’t render. I did use the “to post source code in comment tags, but the xml did not render. Sorry.

Steve
Guest
Steve

Thanks for this. It worked fine for me.

In case anyone wants to build the war using gradle rather than maven create the following build.gradle file and add this to it:

apply plugin: ‘java’
apply plugin: ‘war’

repositories {
mavenCentral()
}

dependencies {
providedCompile ‘javax.servlet:servlet-api:2.5’
compile ‘javax:javaee-web-api:6.0’
runtime ‘javax.servlet:jstl:1.1.2’
}

Then the command ‘gradle build’ will create the war file in the directory build/libs

Praveen
Guest
Praveen

Is it possible to have multiple prefixes

like /rest /core

Ravi
Guest
Ravi

Hi,

Do you have a tutorial to setup RESTEasy on Tomcat and not on JBoss AS?

Thanks,
Ravi

Ravi
Guest
Ravi

Well, got it working by simple dropping the war into tomcat’s webapps dir. I thought we had to do something extra for configuring and using resteasy when not using with jboss AS.

Mohan
Guest
Mohan

Hi,
I have deployed the application in Tomcat6.0 , while running the application
i am getting below error
ERROR:”HTTP Status 500 – Wrapper cannot find servlet class org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
or a class it depends on”

please suggest me which plug in i need to add to resolve this.

mohan
Guest
mohan

Hi Ravi,
I have copied the above application in Tomact 6.0 , i have added the jars also.
After deploying while running the application i am getting below error.Please share
what are the extra configurations we need to do at Tomcat End.

Peter
Guest
Peter

Same; I didn’t know RESTEasy won’t run on Tomcat. I’m wondering how to configure Tomcat…

Leo
Guest
Leo

Does it work in cross-origin request (CORS)? I couldn’t make it work…

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Foster
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Foster

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