Create a Maven project named rest with the following structure:

Declare the dependencies needed for the demo REST service in the pom.xml of the Java project (you can go to the eXo Platform repository to check the artifact versions).

The pom.xml file now looks like:

<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/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>exo.rest.service</groupId>

    <artifactId>rest</artifactId>

    <packaging>jar</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>maven</name>

    <url>http://maven.apache.org</url>

    <dependencies>

        <dependency>

            <groupId>org.exoplatform.ws</groupId>

            <artifactId>exo.ws.rest.core</artifactId>

            <version>2.3.7-GA</version>

            <scope>provided</scope>

        </dependency>    

        <dependency>

            <groupId>org.exoplatform.core</groupId>

            <artifactId>exo.core.component.organization.api</artifactId>

            <version>2.6.0-GA</version>

            <scope>provided</scope>

        </dependency>

        <dependency>

            <groupId>javax.annotation</groupId>

            <artifactId>jsr250-api</artifactId>

            <version>1.0</version>

            <scope>provided</scope>

        </dependency>

        <dependency>

            <groupId>com.metaparadigm</groupId>

            <artifactId>json-rpc</artifactId>

            <version>1.0</version>

            <scope>provided</scope>

        </dependency>

    </dependencies>

</project>

Edit the java/exo/rest/service/RestUserService.java file.

package exo.rest.service;


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.CacheControl;

import javax.ws.rs.core.Context;

import javax.ws.rs.core.MediaType;

import javax.ws.rs.core.Response;

import javax.ws.rs.core.SecurityContext;


import javax.annotation.security.RolesAllowed;


import org.exoplatform.commons.utils.ListAccess;

import org.exoplatform.container.ExoContainer;

import org.exoplatform.container.ExoContainerContext;

import org.exoplatform.services.organization.OrganizationService;

import org.exoplatform.services.organization.User;

import org.exoplatform.services.organization.UserHandler;

import org.exoplatform.services.rest.resource.ResourceContainer;

import org.exoplatform.services.security.Identity;

import org.exoplatform.services.security.IdentityRegistry;

import org.json.JSONArray;

import org.json.JSONObject;


/**

 * Rest User Service!

 */

@Path("/demo")

@Produces("application/json")

public class RestUserService implements ResourceContainer {


  @GET

  @Path("/hello/{name}")

  @RolesAllowed({"administrators"}) 

  public String hello(@PathParam("name")

  String name) {

    return "Hello " + name;

  }


  @GET

  @Path("/listusers/{offet}")

  public Response getListUserName(@Context  SecurityContext sc,@PathParam("offet") Integer offset) {

    JSONArray list = new JSONArray();

    JSONObject jsonObject = new JSONObject();

    String groupToCheck = "/platform/administrators";

CacheControl cacheControl = new CacheControl();       cacheControl.setNoCache(true);

    cacheControl.setNoStore(true);


    if (sc.getUserPrincipal() == null || !this.isMemberOf(sc.getUserPrincipal().getName(), groupToCheck)) {


      jsonObject.put("rights","NOT-ALLOWED");

      list.put(jsonObject);


    } else {


      OrganizationService organizationService = (OrganizationService) ExoContainerContext.getCurrentContainer()

                                                                                         .getComponentInstanceOfType(OrganizationService.class);

      UserHandler userHandler = organizationService.getUserHandler();

      try {

        ListAccess<User> allUsers = userHandler.findAllUsers();

        

        if(offset == null || offset < 0)

          offset = 0;

        int limit = 1000;

        int total = limit + offset;

        int totalUsers = allUsers.getSize();

      

        if(offset < totalUsers && total > totalUsers){

          total = totalUsers;

        }

        User[] users = null;


        for (int i = offset; i < total; i++) {

          users = allUsers.load(i,1);

          jsonObject = new JSONObject();

          jsonObject.put("username", users[0].getUserName());

          list.put(jsonObject);

        }

      } catch (Exception e) {

        // TODO Auto-generated catch block

        e.printStackTrace();

      }

      

    }

    

    return Response.ok(list.toString(), MediaType.APPLICATION_JSON).cacheControl(cacheControl).build();


  }


  private boolean isMemberOf(String username, String role) {

    ExoContainer container = ExoContainerContext.getCurrentContainer();

    IdentityRegistry identityRegistry = (IdentityRegistry) container.getComponentInstanceOfType(IdentityRegistry.class);

    Identity identity = identityRegistry.getIdentity(username);

    return identity.isMemberOf(role);

  }


}

In the above code, ResourceContainer needs to be implemented. This is used to make eXo services (for example, the components deployed inside eXo Container) simply and transparently accessible via HTTP in a RESTful manner. In other words, these services should be viewed as a set of REST Resources-endpoints of the HTTP request-response chain. Those services are called ResourceContainers.

Edit the resources/conf/portal/configuration.xml file that declares the REST service component in the portal container.

<?xml version="1.0" encoding="ISO-8859-1"?>

<configuration>

    <component>

        <type>exo.rest.service.RestUserService</type>

    </component>

</configuration>

Build the Maven project using the command: mvn clean install.

Put the .jar file into the eXo Platform package.

Restart the server, then open http://mycompany.com:8080/portal/rest/demo/listusers/0 in your browser.