Intro Tutorial

A great way to get introduced to Reststop is to work through this tutorial, which walks you through the creation of an Reststop based web app. The app implements a simple REST UserService with an front-end.

Create an Reststop applikasjon

• Create an initial project using:

  • mvn -U org.kantega.reststop:reststop-maven-plugin:RELEASE:create

• Goto http://localhost:8080/helloworld

Look ma, no restarts!

• Open project in your IDE
• Edit HelloworldResource.java and adds some politeness to the greeting: Resource should output "Hello dear world"
• Reload the page in your browser
• Edit HelloworldResource.java: Resource should output "Hello dear Trondheim"
• Reload the page in your browser
• What happened? Find the relevant test and update it
• Reload and see the updated output
• Add compile error to HelloWorldResource.java and reload the page. What do you see?

Looking at the Maven structure

• plugins/helloworld/ is... a plugin!
• plugins/pom.xml: Common build configuration for all plugins
• webapp/pom.xml:
  • List of plugins (yours or others) to include: <plugins>..</plugins>
  • Configuration of jetty:run

Creating an service-interface

• Define a service interface UserService.java in the API plugin:

public interface UserService {
     List<User> getAllUsers();
}

• Define the User class:

public class User {
    private String username;
    private String fullName;
     // TODO: Add getters and setters
}

Create a plugin for implementing UserService

• mvn reststop:create-plugin
  • name: userservice
• userservice-plugin needs to have a <dependency> on the api plugin. Make sure the to add <scope>provided</scope>
• Implement a mock UserServiceImpl returning a few User objects
• In your UserServicePlugin constructor, create a new UserServiceImpl and assign it to a field
• Export the UserService field using the @Export annotation
• Creation of a new plugins or dependency changes currently requires a server restart, so stop the jetty instance, change to root of project and run:
  • mvn install and mvn -f webapp/pom.xml jetty:run

Create a rest-plugin which will consume UserService

• mvn reststop:create-plugin
  • name: rest
• Add dependency on Reststop's jaxrs-api plugin:

<dependency>
    <groupId>org.kantega.reststop</groupId>
    <artifactId>reststop-jaxrs-api</artifactId>
    <version>${reststop.version}</version>
    <scope>provided</scope>
</dependency>

• You'll also need a dependency on the API plugin here
• Import the UserService into RestPlugin by adding it to the RestPlugin constructor.
• In RestPlugin.java, add a JAX-RS singleton resource which outputs the UserService's list of users on the path /users
  • Tip: See helloworld plugin's ExamplePlugin.java for how to add JAX-RS resources

Front-end

• mvn reststop:create-plugin
  • name: ui
• Create plugins/ui/src/main/resources/assets/users/index.html
• Create plugins/ui/src/main/resources/assets/users/users.js
• Goto http://localhost:8080/assets/users/index.html
• Use your-favorite.js to fetch users and list them in HTML
  • Tips: Use Webjars to add AngularJS to your app:

<plugin>
   <groupId>org.kantega.reststop</groupId>
   <artifactId>reststop-webjars-plugin</artifactId>
   <version>${reststop.version}</version>
</plugin>

• Then add a normal <dependency> on the AngularJS Webjar in plugins/ui/pom.xml:

<dependency>
   <groupId>org.webjars</groupId>
   <artifactId>angularjs</artifactId>
   <version>1.4.3</version>
</dependency>

• After mvn install and mvn -f webapps/pom.xml jetty:run restart, Angular should be available at http://localhost:8080/webjars/angularjs/1.4.3/angular.min.js

Configuration

• The rest plugin should output a maximum of N (say 10) users. Add a config property for this limit in RestPlugin.java. Annotate it with @Config and give it a defaultValue of 10.
  • Tip: See how @Config is used in ExamplePlugin
• Verify that you can override the defaultvalue by adding a property in webapp/src/config/exampleservice.conf

Development console

• Goto http://localhost:8080/dev
• Shows information about plugin dependencies and other Reststop related information.