Article summary

Summary

Discusses how to create and deploy an Adobe Experience Manager OSGi bundle that consumes data from a third-party Restful web service. In addition, discusses how to invoke an OSGi bundle operation from the client web page.

This article uses an Adobe Maven Archetype project to build an OSGi bundle. If you are not familiar with an Adobe Maven Archetype project, it is recommended that you read the following article: Creating your first AEM Service using an Adobe Maven Archetype project.

This article discusses how to build an OSGi bundle that consumes data from a Restful web service. To learn how to build an OSGi bundle that consumes a SOAP based web service, see Creating Adobe Experience Manager bundles that consume web services.

This article was updated in Dec 2015 to run on AEM 6.1. Included in this update is a 6.1 AEM sample package. 

Digital Marketing Solution(s) Adobe Experience Manager (Adobe CQ)
Audience
Developer (intermediate)
Required Skills
Java, JQuery, Restful HTTP, JSON
Tested On Adobe Experiene Manager 5.5, 5.6, 6.x

Note:

You can download an AEM package that contains code and the OSGi bundle that are used in this article. Download the package and deploy using package manager. The purpose of this code is to show the communtiy these concepts in action. That is, it's to illustrate how to write an OSGi bundle that use Rest to invoke a 3rd party Restful web service.

This community code is for teaching purposes only and not meant to go into production as is. You can view the sample community application by using the following URL: http://localhost:4502/cf#/content/restfulAEMClient.html (assuming you deploy on author). 

Download

Note:

This article uses a JSP to display Restful data. If you are interested in developing an HTL component that displays Restful data for Experience Manager 6.2, see Creating an AEM HTML Template Language Component that displays data from a Restful Web Service.

Introduction

You can create an Adobe Experience Manager bundle that consumes data from a third-party Restful web service and displays the data in an AEM web page. For example, assume that you have a requirement to create an AEM component that calculates the distance between two cities and displays the results in an AEM web page. In this situation, you can develop an OSGi bundle that contains Java classes located in the org.apache.http package that can invoke a third-party Restful web service.

The following illustration shows data being retrieved from a third-party Restful web service and displayed in an AEM web page (JSP).
 

RestBundle2

The use case in this article is to calculate the distance between two cities, return the data within JSON, parse the JSON using JavaScript, and display the results in an AEM web page.

client2

 

To calculate the distance between two cities, the Google Distance Matrix API is used. For information about this API, see:

https://developers.google.com/maps/documentation/distancematrix/

Create an AEM application folder structure 

Create an AEM application folder structure that contains templates, components, and pages by using CRXDE Lite. 

CQAppSetup

The following describes each application folder:

  • application name: contains all of the resources that an application uses. The resources can be templates, pages, components, and so on.
  • components: contains components that your application uses. 
  • page: contains page components. A page component is a script such as a JSP file. 
  • global: contains global components that your application uses.
  • template: contains templates on which you base page components. 
  • src: contains source code that comprises an OSGi component (this development article does not create an OSGi bundle using this folder). 
  • install: contains a compiled OSGi bundles container.
To create an AEM application folder structure:
  1. To view the CQ welcome page, enter the URL http://[host name]:[port] into a web browser. For example, http://localhost:4502.
  2. Select CRXDE Lite (if you are using AEM 5.6, click Tools from the left menu). 
  3. Right-click the apps folder (or the parent folder), select Create, Create Folder.
  4. Enter the folder name into the Create Folder dialog box. Enter restservice
  5. Repeat steps 1-4 for each folder specified in the previous illustration. 
    Click the Save All button.

Note:

You have to click the Save All button when working in CRXDE Lite for the changes to be made.

Create a template 

You can create a template by using CRXDE Lite. A CQ template enables you to define a consistent style for the pages in your application. A template comprises of nodes that specify the page structure. For more information about templates, see Templates

 

To create a template, perform these tasks:

1. To view the CQ welcome page, enter the URL http://[host name]:[port] into a web browser. For example, http://localhost:4502.
2. Select CRXDE Lite (if you are using AEM 5.6, click Tools from the left menu).
3. Right-click the template folder (within your application), select Create, Create
Template.
4. Enter the following information into the Create Template dialog box:

  • Label: The name of the template to create. Enter templateRest
  • Title: The title that is assigned to the template.
  • Description: The description that is assigned to the template.
  • Resource Type: The component's path that is assigned to the template and copied to implementing pages. Enter restservice/components/page/templateRest.
  • Ranking: The order (ascending) in which this template will appear in relation to other templates. Setting this value to 1 ensures that the template appears first in the list.

5. Add a path to Allowed Paths. Click on the plus sign and enter the following value: /content(/.*)?
6. Click Next for Allowed Parents.
7. Select OK on Allowed Children.

Create a render component that uses the template 

Components are re-usable modules that implement specific application logic to render the content of your web site. You can think of a component as a collection of scripts (for example, JSPs, Java servlets, and so on) that completely realize a specific function. In order to realize this functionality, it is your responsibility as a CQ developer to create scripts that perform specific functionality. For more information about components, see Components

By default, a component has at least one default script, identical to the name of the component. To create a render component, perform these tasks:

1. To view the CQ welcome page, enter the URL http://[host name]:[port] into a web browser. For example, http://localhost:4502.
2. Select CRXDE Lite (if you are using AEM 5.6, click Tools from the left menu).
3. Right-click /apps/jcrquery/components/page, then select
Create, Create Component.
4. Enter the following information into the Create Component dialog box:

  • Label: The name of the component to create. Enter templateRest
  • Title: The title that is assigned to the component.
  • Description: The description that is assigned to the template.
  • Super Type: foundation/components/page (in AEM 6, you specify this value for page components. In previous versions of AEM, this was not required.)

5. Select Next for Advanced Component Settings and Allowed Parents.
6. Select OK on Allowed Children.
7. Open the templateQueryjsp located at: /apps/restservice/components/page/templateRest/templateRest.jsp.
8. Enter the following JSP code.

<html>
<head>
<title>Hello Restful Service!!!</title>
</head>
<body>
<h1>Hello Restful Service!!!</h1>
<h2>This page will display data returned by a Restful service</h2>
</body>
</html>

Setup Maven in your development environment

You can use Maven to build an OSGi bundle that uses the JCR API and is deployed to Experience Manager. Maven manages required JAR files that a Java project needs in its class path. Instead of searching the Internet trying to find and download third-party JAR files to include in your project’s class path, Maven manages these dependencies for you.

You can download Maven 3 from the following URL:

http://maven.apache.org/download.html

After you download and extract Maven, create an environment variable named M3_HOME. Assign the Maven install location to this environment variable. For example:

C:\Programs\Apache\apache-maven-3.0.4

Set up a system environment variable to reference Maven. To test whether you properly setup Maven, enter the following Maven command into a command prompt:

%M3_HOME%\bin\mvn -version

This command provides Maven and Java install details and resembles the following message:

OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"

Note:

For more information about setting up Maven and the Home variable, see: Maven in 5 Minutes.

Next, copy the Maven configuration file named settings.xml from [install location]\apache-maven-3.0.4\conf\ to your user profile. For example, C:\Users\scottm\.m2\.

You have to configure your settings.xml file to use Adobe’s public repository. For information, see Adobe Public Maven Repository at http://repo.adobe.com/.

The following XML code represents a settings.xml file that you can use.

<?xml version="1.0" encoding="UTF-8"?>

<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

<!--
 | This is the configuration file for Maven. It can be specified at two levels:
 |
 |  1. User Level. This settings.xml file provides configuration for a single user, 
 |                 and is normally provided in ${user.home}/.m2/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -s /path/to/user/settings.xml
 |
 |  2. Global Level. This settings.xml file provides configuration for all Maven
 |                 users on a machine (assuming they're all using the same Maven
 |                 installation). It's normally provided in 
 |                 ${maven.home}/conf/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -gs /path/to/global/settings.xml
 |
 | The sections in this sample file are intended to give you a running start at
 | getting the most out of your Maven installation. Where appropriate, the default
 | values (values used when the setting is not specified) are provided.
 |
 |-->
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <!-- localRepository
   | The path to the local repository maven will use to store artifacts.
   |
   | Default: ~/.m2/repository
  <localRepository>/path/to/local/repo</localRepository>
  -->

  <!-- interactiveMode
   | This will determine whether maven prompts you when it needs input. If set to false,
   | maven will use a sensible default value, perhaps based on some other setting, for
   | the parameter in question.
   |
   | Default: true
  <interactiveMode>true</interactiveMode>
  -->

  <!-- offline
   | Determines whether maven should attempt to connect to the network when executing a build.
   | This will have an effect on artifact downloads, artifact deployment, and others.
   |
   | Default: false
  <offline>false</offline>
  -->

  <!-- pluginGroups
   | This is a list of additional group identifiers that will be searched when resolving plugins by their prefix, i.e.
   | when invoking a command line like "mvn prefix:goal". Maven will automatically add the group identifiers
   | "org.apache.maven.plugins" and "org.codehaus.mojo" if these are not already contained in the list.
   |-->
  <pluginGroups>
    <!-- pluginGroup
     | Specifies a further group identifier to use for plugin lookup.
    <pluginGroup>com.your.plugins</pluginGroup>
    -->
  </pluginGroups>

  <!-- proxies
   | This is a list of proxies which can be used on this machine to connect to the network.
   | Unless otherwise specified (by system property or command-line switch), the first proxy
   | specification in this list marked as active will be used.
   |-->
  <proxies>
    <!-- proxy
     | Specification for one proxy, to be used in connecting to the network.
     |
    <proxy>
      <id>optional</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>proxyuser</username>
      <password>proxypass</password>
      <host>proxy.host.net</host>
      <port>80</port>
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
    -->
  </proxies>

  <!-- servers
   | This is a list of authentication profiles, keyed by the server-id used within the system.
   | Authentication profiles can be used whenever maven must make a connection to a remote server.
   |-->
  <servers>
    <!-- server
     | Specifies the authentication information to use when connecting to a particular server, identified by
     | a unique name within the system (referred to by the 'id' attribute below).
     | 
     | NOTE: You should either specify username/password OR privateKey/passphrase, since these pairings are 
     |       used together.
     |
    <server>
      <id>deploymentRepo</id>
      <username>repouser</username>
      <password>repopwd</password>
    </server>
    -->
    
    <!-- Another sample, using keys to authenticate.
    <server>
      <id>siteServer</id>
      <privateKey>/path/to/private/key</privateKey>
      <passphrase>optional; leave empty if not used.</passphrase>
    </server>
    -->
  </servers>

  <!-- mirrors
   | This is a list of mirrors to be used in downloading artifacts from remote repositories.
   | 
   | It works like this: a POM may declare a repository to use in resolving certain artifacts.
   | However, this repository may have problems with heavy traffic at times, so people have mirrored
   | it to several places.
   |
   | That repository definition will have a unique id, so we can create a mirror reference for that
   | repository, to be used as an alternate download site. The mirror site will be the preferred 
   | server for that repository.
   |-->
  <mirrors>
    <!-- mirror
     | Specifies a repository mirror site to use instead of a given repository. The repository that
     | this mirror serves has an ID that matches the mirrorOf element of this mirror. IDs are used
     | for inheritance and direct lookup purposes, and must be unique across the set of mirrors.
     |
    <mirror>
      <id>mirrorId</id>
      <mirrorOf>repositoryId</mirrorOf>
      <name>Human Readable Name for this Mirror.</name>
      <url>http://my.repository.com/repo/path</url>
    </mirror>
     -->
  </mirrors>
  
  <!-- profiles
   | This is a list of profiles which can be activated in a variety of ways, and which can modify
   | the build process. Profiles provided in the settings.xml are intended to provide local machine-
   | specific paths and repository locations which allow the build to work in the local environment.
   |
   | For example, if you have an integration testing plugin - like cactus - that needs to know where
   | your Tomcat instance is installed, you can provide a variable here such that the variable is 
   | dereferenced during the build process to configure the cactus plugin.
   |
   | As noted above, profiles can be activated in a variety of ways. One way - the activeProfiles
   | section of this document (settings.xml) - will be discussed later. Another way essentially
   | relies on the detection of a system property, either matching a particular value for the property,
   | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a 
   | value of '1.4' might activate a profile when the build is executed on a JDK version of '1.4.2_07'.
   | Finally, the list of active profiles can be specified directly from the command line.
   |
   | NOTE: For profiles defined in the settings.xml, you are restricted to specifying only artifact
   |       repositories, plugin repositories, and free-form properties to be used as configuration
   |       variables for plugins in the POM.
   |
   |-->
  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting
     | to accomplish, particularly when you only have a list of profile id's for debug.
     |
     | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo.
    <profile>
      <id>jdk-1.4</id>

      <activation>
        <jdk>1.4</jdk>
      </activation>

      <repositories>
        <repository>
          <id>jdk14</id>
          <name>Repository for JDK 1.4 builds</name>
          <url>http://www.myhost.com/maven/jdk14</url>
          <layout>default</layout>
          <snapshotPolicy>always</snapshotPolicy>
        </repository>
      </repositories>
    </profile>
    -->

    <!--
     | Here is another profile, activated by the system property 'target-env' with a value of 'dev',
     | which provides a specific path to the Tomcat instance. To use this, your plugin configuration
     | might hypothetically look like:
     |
     | ...
     | <plugin>
     |   <groupId>org.myco.myplugins</groupId>
     |   <artifactId>myplugin</artifactId>
     |   
     |   <configuration>
     |     <tomcatLocation>${tomcatPath}</tomcatLocation>
     |   </configuration>
     | </plugin>
     | ...
     |
     | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to
     |       anything, you could just leave off the <value/> inside the activation-property.
     |
    <profile>
      <id>env-dev</id>

      <activation>
        <property>
          <name>target-env</name>
          <value>dev</value>
        </property>
      </activation>

      <properties>
        <tomcatPath>/path/to/tomcat/instance</tomcatPath>
      </properties>
    </profile>
    -->
  

<profile>

                <id>adobe-public</id>

                <activation>

                    <activeByDefault>true</activeByDefault>

                </activation>

                <repositories>

                  <repository>

                    <id>adobe</id>

                    <name>Nexus Proxy Repository</name>

                    <url>http://repo.adobe.com/nexus/content/groups/public/</url>

                    <layout>default</layout>

                  </repository>

                </repositories>

                <pluginRepositories>

                  <pluginRepository>

                    <id>adobe</id>

                    <name>Nexus Proxy Repository</name>

                    <url>http://repo.adobe.com/nexus/content/groups/public/</url>

                    <layout>default</layout>

                  </pluginRepository>

                </pluginRepositories>

            </profile>

</profiles>

  <!-- activeProfiles
   | List of profiles that are active for all builds.
   |
  <activeProfiles>
    <activeProfile>alwaysActiveProfile</activeProfile>
    <activeProfile>anotherAlwaysActiveProfile</activeProfile>
  </activeProfiles>
  -->
</settings>

Create an Experience Manager archetype project 

You can create an Experience Manager archetype project by using the Maven archetype plugin. In this example, assume that the working directory is C:\AdobeCQ.

plugin1

To create an Experience Manager archetype project, perform these steps::

1. Open the command prompt and go to your working directory (for example, C:\AdobeCQ).

2. Run the following Maven command:

mvn archetype:generate -DarchetypeRepository=https://repo.adobe.com/nexus/content/groups/public/ -DarchetypeGroupId=com.day.jcr.vault -DarchetypeArtifactId=multimodule-content-package-archetype -DarchetypeVersion=1.0.2 -DgroupId=com.adobe.restservice  -DartifactId=restful -Dversion=1.0-SNAPSHOT -Dpackage=com.adobe.restservice  -DappsFolderName=myproject -DartifactName="My Project" -DcqVersion="5.6.1" -DpackageGroup="My Company"

3. When prompted for additional information, specify Y.

4. Once done, you will see a message like:

[INFO] Finished at: Wed Mar 27 13:38:58 EDT 2013
[INFO] Final Memory: 10M/184M

5. Change the command prompt to the generated project. For example: C:\AdobeCQ\restful. Run the following Maven command:

mvn eclipse:eclipse

After you run this command, you can import the project into Eclipse as discussed in the next section.

Add Java files to the Maven project using Eclipse 

To make it easier to work with the Maven generated project, import it into the Eclipse development environment, as shown in the following illustration.

import

Note:

Delete all packages and files that were created by the Maven archetype project. Keep only the com.adobe.restservice package and the Java files created in this section. 

The next step is to add Java files to the com.adobe.restservice package. The Java files that you create in this section use the Apache HttpClient API. This API lets you perform a GET operation to get data from the Restful Google service. For information about the Apache HttpClient API, see http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/.

Add the following Java files to the com.adobe.restservice package:

  • A Java interface named Distance.
  • A Java class named DistanceImpl that extends the Distance interface.

Distance interface

The following code represents the Distance interface. This interface contains a method signatures named getDistance. The implementation logic for this method is located in the DistanceImpl class. The getDistance method uses the Apache HTTPClient API to invoke the Google Restful Service.

The following Java code represents the Distance interface.  

package com.adobe.restservice;

public interface Distance {
	
	//Returns JSON encoded data that represents the distance between two cities
	public String getDistance(); 

}

DistanceImpl class

The DistanceImp class uses the following Apache Felix SCR annotations to create the OSGi component:

  • @Component – defines the class as a component
  • @Service - defines the service interface that is provided by the component

In this development article, a DefaultHttpClient instance is created. Next, a HTTPGET object is created. This object specifies the URL of the Google Restful request, as shown here.

HttpGet getRequest = new HttpGet("http://maps.googleapis.com/maps/api/distancematrix/json?origins=Vancouver%20BC&destinations=San%20Francisco&sensor=false");
getRequest.addHeader("accept", "application/json");

The Restful request is sent by using the DefaultHttpClient object's  execute and passing the HttpGet object.

HttpResponse response = httpClient.execute(getRequest);

The return data is encoded as JSON, as shown here:

{ "destination_addresses" : [ "San Francisco, CA, USA" ],
  "origin_addresses" : [ "Vancouver, BC, Canada" ],
  "rows" : [ { "elements" : [ { "distance" : { "text" : "1,526 km",
                  "value" : 1526076
                },
              "duration" : { "text" : "14 hours 32 mins",
                  "value" : 52305
                },
              "status" : "OK"
            } ] } ],
  "status" : "OK"
}

Note:

This is the JSON data returned by the Google service. This is the data returned by the getDistance method. The JSON data is parsed by the AEM page component and the values are displayed in the AEM web page.

To retrieve the JSON data, you use the HTTPResponse object, as shown here.

BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));

String output;
String myJSON="" ;
while ((output = br.readLine()) != null) {

    //Get the JSON data
     myJSON = myJSON + output;
}


The following data represents the DistanceImpl class that extends the Distance interface.

package com.adobe.restservice;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Service;

//This is a component so it can provide or consume services
@Component
  
   
@Service

public class DistanceImpl implements Distance {

	@Override
	public String getDistance() {
		// TODO Auto-generated method stub
		
		try
		{
			DefaultHttpClient httpClient = new DefaultHttpClient();
			 
		    HttpGet getRequest = new HttpGet("http://maps.googleapis.com/maps/api/distancematrix/json?origins=Vancouver%20BC&destinations=San%20Francisco&sensor=false");
			getRequest.addHeader("accept", "application/json");

			HttpResponse response = httpClient.execute(getRequest);

			if (response.getStatusLine().getStatusCode() != 200) {
			                throw new RuntimeException("Failed : HTTP error code : "
			                        + response.getStatusLine().getStatusCode());
			            }

			BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));

			String output;
			 String myJSON="" ;
	            while ((output = br.readLine()) != null) {
	                //System.out.println(output);
	                myJSON = myJSON + output;
	            }

			 
			httpClient.getConnectionManager().shutdown();
			return myJSON ;
		}
		
		catch (Exception e)
		{
			e.printStackTrace() ; 
		}
		
		return null;
	}

}

Including HTTP client packages to CQ

Depending on what OSGi bundles that you have deployed to CQ, you may have to include additional client HTTP packages to CQ so that the service that invokes the Restful web service can be placed into an active state. By default, there may be missing packages, such as org.apache.http.client.methods, that will prevent you from placing the OSGi bundle into an active state.

To include the client HTTP packages, first download these JAR files: httpclient-4.0.jar (or an older version) and httpcore-4.3.2.jar. Next, place these files into a bundle. To create an OSGi bundle that contains client HTTP packages, perform these tasks:

1. Start Eclipse (Indigo works best). The steps below have been tested on Eclipse Java EE IDE for Web Developers version Indigo Service Release 1.

2. Select File, New, Other.

3. Under the Plug-in Development folder, choose Plug-in from Existing JAR Archives. Name your project httpBundle.

4. In the JAR selection dialog, click the Add external button, and browse to the HTTP JAR files that you downloaded.

5. Click Next.

6. In the Plug-in Project properties dialog, ensure that you check the checkbox for Analyze library contents and add dependencies.

7. Make sure that the Target Platform is the standard OSGi framework.

8. Ensure the checkboxes for Unzip the JAR archives into the project and Update references to the JAR files are both checked.

9. Click Next, and then Finish.

10. Click the Runtime tab.

11. Make sure that the Exported Packages list is populated.

12. Make sure these packages have been added under the Export-Package header in MANIFEST.MF. Remove the version information in the MANIFEST.MF file. Version numbers can cause conflicts when you upload the OSGi bundle.

13. Also make sure that the Import-Package header in MANIFEST.MF is populated.
14. Save the project.

15. Build the OSGi bundle by right-clicking the project in the left pane, choose Export, Plug-in Development, Deployable plug-ins and fragments, and click Next.

16. Select a location for the export (C:\TEMP) and click Finish. (Ignore any error messages).

17. In C:\TEMP\plugins, you should now find the OSGi bundle.

18. Login to the Apache Felix Web Console at http://server:port/system/console/bundles (default admin user = admin with password= admin).

19. Sort the bundle list by Id and note the Id of the last bundle.

20. Click the Install/Update button.

21. Check the Start Bundle checkbox.

22. Browse to the bundle JAR file you just built. (C:\TEMP\plugins).

23. Click Install.

24. Click the Refresh Packages button.

25. Check the bundle with the highest Id.

26. Your new bundle should now be listed with the status Active.

27. If the status is not Active, check the error.log for exceptions. If you get “org.osgi.framework.BundleException: Unresolved constraint” errors, check the MANIFEST.MF for strict version requirements which might follow: javax.xml.namespace; version=”3.1.0”

28. If the version requirement causes problems, remove it so that the entry looks like this: javax.xml.namespace.

29. If the entry is not required, remove it entirely.

30. Rebuild the bundle.

31. Delete the previous bundle and deploy the new one.

Modify the Maven POM file

Modify the POM files to successfully build the OSGi bundle. In the POM file located at C:\AdobeCQ\restfulservice\bundle, add the following dependencies.

  • org.apache.felix.scr
  • org.apache.felix.scr.annotations
  • org.apache.httpcomponents
  • org.apache.sling

The following XML represents this POM file.

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <!-- ====================================================================== -->
    <!-- P A R E N T P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->
    <parent>
        <groupId>com.adobe.restservice</groupId>
        <artifactId>restful</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <!-- ====================================================================== -->
    <!-- P R O J E C T D E S C R I P T I O N -->
    <!-- ====================================================================== -->

    <artifactId>restful-bundle</artifactId>
    <packaging>bundle</packaging>
    <name>My Project Bundle</name>

    <dependencies>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.compendium</artifactId>
        </dependency>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.felix</groupId>
            <artifactId>org.apache.felix.scr.annotations</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>
           
            
        <dependency>
         <groupId>org.apache.felix</groupId>
     
         <artifactId>org.osgi.core</artifactId>
     
         <version>1.4.0</version>
      </dependency>
           
          
            
    <dependency>
    <groupId>org.apache.jackrabbit</groupId>
    <artifactId>jackrabbit-core</artifactId>
    <version>2.4.3</version>
    </dependency>
         
    <dependency>
    <groupId>org.apache.jackrabbit</groupId>
    <artifactId>jackrabbit-jcr-commons</artifactId>
    <version>2.4.3</version>
    </dependency>
   <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
         
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.1.1</version>
    </dependency>
             
    <dependency>
            <groupId>org.apache.sling</groupId>
            <artifactId>org.apache.sling.api</artifactId>
            <version>2.2.4</version>
            <scope>provided</scope>
        </dependency>
        </dependencies>

    <!-- ====================================================================== -->
    <!-- B U I L D D E F I N I T I O N -->
    <!-- ====================================================================== -->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-scr-plugin</artifactId>
                <executions>
                    <execution>
                        <id>generate-scr-descriptor</id>
                        <goals>
                            <goal>scr</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <Bundle-SymbolicName>com.adobe.restservice.restful-bundle</Bundle-SymbolicName>
                    </instructions>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.sling</groupId>
                <artifactId>maven-sling-plugin</artifactId>
                <configuration>
                    <slingUrl>http://${crx.host}:${crx.port}/apps/myproject/install</slingUrl>
                    <usePut>true</usePut>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                 <configuration>
                    <excludePackageNames>
                        *.impl
                    </excludePackageNames>
                 </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Build the OSGi bundle using Maven 

To build the OSGi component by using Maven, perform these steps:

  1. Open the command prompt and go to the C:\AdobeCQ\restservice folder.
  2. Run the following maven command: mvn clean install.
  3. The OSGi component can be found in the following folder: C:\AdobeCQ\restservice\bundle\target. The file name of the OSGi component is restfulservice-bundle-1.0-SNAPSHOT.jar.

Deploy the bundle to Experience Manager

Once you deploy the OSGi bundle, you are able to invoke the getDistance method defined in the DistanceImpl class (this is shown later in this development article). After you deploy the OSGi bundle, you will be able to see it in the Apache Felix Web Conole.

OSGI_Console

Deploy the OSGi bundle by performing these steps:

  1. Login to the Apache Felix Web Console at http://server:port/system/console/bundles (default admin user = admin with password= admin).
  2. Click the Bundles tab, sort the bundle list by Id, and note the Id of the last bundle.
  3. Click the Install/Update button.
  4. Browse to the bundle JAR file you just built using Maven. (C:\AdobeCQ\restservice\bundle\target).
  5. Click Install.
  6. Click the Refresh Packages button.
  7. Check the bundle with the highest Id.
  8. Click Active. Your new bundle should now be listed with the status Active.
  9. If the status is not Active, check the CQ error.log for exceptions.

 

Note:

The name of the service defined within the OSGi bundle is com.adobe.restservice.Distance.

Add JQuery files to a CQ:ClientLibraryFolder node  

You add a JQuery framework file to a cq:ClientLibraryFolder node that is used by the client JSP. The JQuery framework file that is added is named jquery-1.6.3.min.js. To add the JQuery framework, add a new node named clientlibs to your component (as discussed later). Add these two properties to this node.

Name  Type  Value 
dependencies  String[]  cq.jquery 
categories  String[]  jquerysamples 

The dependencies property informs Experience Manager to include the CSS files and JQuery libraries in the page. The categories property informs Experience Manager which clientlibs must be included.

After you create the Clientlibs folder, add the JQuery library files, and a map text file. The names of the text files is js.txt. The js.txt file contains the JS file name: jquery-1.6.3.min.js.

Add the files to the ClientLibs folder:

  1. Right-click /apps/jcrquery/components then select New, Node.
  2. Make sure that the node type is cq:ClientLibraryFolder and name the node clientlibs.
  3. Right click on clientlibs and select Properties. Add the two properties specified in the previous table to the node.
  4. On your file system, navigate to the folder where the JQuery JS file is located. Drag and drop the JS files to the clientlibs node by using CRXDE.

Modify the Client JSP to invoke the getDistance method

To create the AEM client that displays data returned by the Restful service, create these files:

  • query.json.jsp: contains application logic that calls the OSGi bundle's getDistance method.
  • templateRest.jsp: contains application logic that parses the JSON data and displays data returned by the getDistance method.  

Create the query.json.jsp 

Add a new JSP file named query.json.jsp to the following JCR path:

/apps/restservice/components/page/templateRest

In query.json.jsp, you create a Distance instance by using the sling.getService method, as shown in the following example:

com.adobe.restservice.Distance cs = sling.getService(com.adobe.restservice.Distance.class);

You pass the fully qualified name of the service to sling.getService method. After you create a Distance object by using sling.getService, you can invoke the getDistance method exposed by the service.

The following code represents the query.json.jsp file. 

<%@include file="/libs/foundation/global.jsp"%>
<%@ page import="org.apache.sling.commons.json.io.*,org.w3c.dom.*" %><%
String filter = request.getParameter("filter");
  
com.adobe.restservice.Distance cs = sling.getService(com.adobe.restservice.Distance.class);
  
String myJSON= cs.getDistance() ; 
   
//Send the data back to the client 
JSONWriter writer = new JSONWriter(response.getWriter());
writer.object();
writer.key("json");
writer.value(myJSON);
  
writer.endObject();
%>

Modify the templateRest.jsp 

Modify the templateRest.jsp file to call the query.json.jsp. In this example, a JQuery Ajax HTTP request is used. Notice that the JSON data (returned by the getDistance method) is parsed in the success method of the AJAX call.  

$('#submit').click(function() {
    var failure = function(err) {
      
        alert("Unable to retrive data "+err);
          
    };
   
   //Set the Request to query.json   
    var url = location.pathname.replace(".html", "/_jcr_content.query.json");
  
    $.ajax(url, {
        dataType: "text",
        success: function(rawData, status, xhr) {
            var data;
            try {
            	//Get the values from JSON encoded Data
                var json = JSON.parse(rawData);
            	var json2 = jQuery.parseJSON(json.json);
        	var orginalCity=json2.origin_addresses[0];;
            	var destinCity=json2.destination_addresses[0];
            	var distance = json2.rows[0].elements[0].distance.text ; 
                  
            	
                //Set the fields in the HTML form
                $('#destination').val(destinCity);
                $('#original').val(orginalCity);
                $('#distance').val(distance);
               
             
            } catch(err) {
                failure(err);
            }
        },
        error: function(xhr, status, err) {
            failure(err);
        } 
    });

The following code represents the entire TemplateRest.jsp file.

<%@include file="/libs/foundation/global.jsp"%>
<cq:includeClientLib categories="jquerysamples" />
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Adobe CQ Restful Service example</title>
<script>
$(document).ready(function() {

    $('body').hide().fadeIn(5000);
      
$('#submit').click(function() {
    var failure = function(err) {
      
        alert("Unable to retrive data "+err);
          
    };
   
   //Set the Request to query.json   
    var url = location.pathname.replace(".html", "/_jcr_content.query.json");
  
    $.ajax(url, {
        dataType: "text",
        success: function(rawData, status, xhr) {
            var data;
            try {
            	var json = JSON.parse(rawData);

            	var json2 = jQuery.parseJSON(json.json);


            	//Get the values from JSON encoded Data
            	var orginalCity=json2.origin_addresses[0];;
                
            	var destinCity=json2.destination_addresses[0];
            	var distance = json2.rows[0].elements[0].distance.text ; 
                  
            	
                //Set the fields in the forum
                $('#destination').val(destinCity);
                $('#original').val(orginalCity);
                $('#distance').val(distance);
               
             
            } catch(err) {
                failure(err);
            }
        },
        error: function(xhr, status, err) {
            failure(err);
        } 
    });
  });
 


  
}); // end ready
</script>
 
</head>
<body>
<div class="wrapper">
   
    <div class="main">
    <h1>Adobe Experience Manager Restful Service Example</h1>
    <h3>Calculate the distance between San Francisco CA and Vancouver BC</h3>
      
    <form name="signup" id="signup">
     <table>
     <tr>
    <td>
    <label for="last">Destination City:</label>
    </td>
     <td>
    <input type="destination" id="destination" name="destination" value="" />
    </td>
    </tr>
    <tr>
    <td>
    <label for="last">Original City:</label>
    </td>
     <td>
    <input type="original" id="original" name="original" value="" />
    </td>
    </tr>
    
    <tr>
    <td>
    <label for="first">Distance:</label>
    </td>
     <td>
    <input type="distance" id="distance" name="distance" value="" />
    </td>
    </tr>
   
     
</table>
            <div>
                <input type="button" value="Get Distance!"  name="submit" id="submit" value="Submit">
            </div>
      </form>
      </div>
    </div>
   
</body>
</html>

Modify the templateRest.jsp file.

  1. To view the welcome page, enter the URL: http://[host name]:[port] into a web browser. For example, http://localhost:4502.
  2. Select CRXDE Lite. (If you are using AEM 5.6, click Tool in the left menu).
  3. Double-click apps/restservice/components/page/templateRest/templateRest.jsp.
  4. Replace the JSP code with the new code shown in this section.
  5. Click Save All.

 

Create an AEM web page that displays data returned by the getDistance method 

The final task is to create a site that contains a page that is based on the templateRest (the template created earlier in this development article). When the user clicks the getDistance button button, the data is displayed.


App


Create an AEM web page that displays data returned by the getDistance method:

  1. Go to the Websites page at http://localhost:4502/siteadmin#/content.
  2. Select New Page.
  3. Specify the title of the page in the Title field.
  4. Specify the name of the page in the Name field.
  5. Select templateRest from the template list that appears. This value represents the template that is created in this development article. If you do not see it, then repeat the steps in this development article. For example, if you made a typing mistake when entering in path information, the template will not show up in the New Page dialog box.
  6. Open the new page that you created by double-clicking it in the right pane. The new page opens in a web browser. You should see a page similar to the previous illustration.

See also

Congratulations, you have just created an AEM OSGi bundle by using an Adobe Maven Archetype project. Please refer to the AEM community page for other articles that discuss how to build AEM services/applications by using an Adobe Maven Archetype project.

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