How to programmatically access the AEM JCR

Last update: April 17, 2024

Topics:
Developing,JCR

CREATED FOR:

Developer

You can programmatically modify nodes and properties located within the Adobe CQ repository, which is part of the Adobe Experience Cloud. To access the CQ repository, you use the Java™ Content Repository (JCR) API. You can use the Java™ JCR API to create, replace, update, and delete (CRUD) content located within the Adobe CQ repository. For more information about the Java™ JCR API, see https://jackrabbit.apache.org/jcr/jcr-api.html.

NOTE

This development article modifies the Adobe CQ JCR from an external Java™ application. In contrast, you can modify the JCR from within an OSGi bundle using the JCR API. For details, see Persisting CQ data in the Java™ Content Repository.

NOTE

To use the JCR API, add the jackrabbit-standalone-2.4.0.jar file to your Java™ application’s class path. You can obtain this JAR file from the Java™ JCR API web page at https://jackrabbit.apache.org/jcr/jcr-api.html.

NOTE

To learn how to query the Adobe CQ JCR using the JCR Query API, see Querying Adobe Experience Manager Data using the JCR API.

Create a Repository instance

Although there are different ways to connect to a repository and establish a connection, this development article uses a static method that belongs to the org.apache.jackrabbit.commons.JcrUtils class. The name of the method is getRepository. This method takes a string parameter that represents the URL of the Adobe CQ server. For example, http://localhost:4503/crx/server.

The getRepository method returns a Repository instance, as shown in the following code example.

//Create a connection to the AEM JCR repository running on local host
Repository repository = JcrUtils.getRepository("http://localhost:4503/crx/server");

Create a Session instance

The Repository instance represents the CRX repository. You use the Repository instance to establish a session with the repository. To create a session, invoke the Repository instance’s login method and pass a javax.jcr.SimpleCredentials object. The login method returns a javax.jcr.Session instance.

You create a SimpleCredentials object by using its constructor and passing the following string values:

The user name;
The corresponding password

When passing the second parameter, call the String object’s toCharArray method. The following code shows how to call the login method that returns a javax.jcr.Sessioninstance.

//Create a Session instance
javax.jcr.Session session = repository.login( new SimpleCredentials("admin", "admin".toCharArray()));

Create a Node instance

Use a Session instance to create a javax.jcr.Node instance. A Node instance lets you perform node operations. For example, you can create a node. To create a node that represents the root node, invoke the Session instance’s getRootNode method, as shown in the following line of code.

//Create a Node
Node root = session.getRootNode();

Once you create a Node instance, you can perform tasks such as creating another node and adding a value to it. For example, the following code creates two nodes and adds a value to the second node.

// Store content
Node day = adobe.addNode("day");
day.setProperty("message", "Adobe CQ is part of the Adobe Digital Marketing Suite!");

Retrieve Node Values

To retrieve a node and its value, invoke the Node instance’s getNode method and pass a string value that represents the fully qualified path to the node. Consider the node structure created in the previous code example. To retrieve the day node, specify adobe/day, as shown in the following code:

// Retrieve content
Node node = root.getNode("adobe/day");
System.out.println(node.getPath());
System.out.println(node.getProperty("message").getString());

Create nodes in the Adobe CQ Repository

The following Java™ code example represents a Java™ class that connects to Adobe CQ, creates a Session instance, and adds new nodes. A node is assigned a data value and then the value of the node and its path is written out to the console. When you are done with the Session, be sure to log out.

/*
 * This Java Quick Start uses the jackrabbit-standalone-2.4.0.jar
 * file. See the previous section for the location of this JAR file
 */

import javax.jcr.Repository;
import javax.jcr.Session;
import javax.jcr.SimpleCredentials;
import javax.jcr.Node;

import org.apache.jackrabbit.commons.JcrUtils;
import org.apache.jackrabbit.core.TransientRepository;

public class GetRepository {

public static void main(String[] args) throws Exception {

try {

    //Create a connection to the CQ repository running on local host
    Repository repository = JcrUtils.getRepository("http://localhost:4503/crx/server");

   //Create a Session
   javax.jcr.Session session = repository.login( new SimpleCredentials("admin", "admin".toCharArray()));

  //Create a node that represents the root node
  Node root = session.getRootNode();

  // Store content
  Node adobe = root.addNode("adobe");
  Node day = adobe.addNode("day");
  day.setProperty("message", "Adobe CQ is part of the Adobe Digital Marketing Suite!");

  // Retrieve content
  Node node = root.getNode("adobe/day");
  System.out.println(node.getPath());
  System.out.println(node.getProperty("message").getString());

  // Save the session changes and log out
  session.save();
  session.logout();
  }
 catch(Exception e){
  e.printStackTrace();
  }
 }
}

After you run the full code example and create the nodes, you can view the new nodes in the CRXDE Lite, as shown in the following illustration.

chlimage_1-68