Convert an AEM asset into byte[] in AEM 6.4?

[singhprabhakar]

Hi,

How can I convert an AEM asset into a byte[]?

I'm using AEM 6.4 for this project and this is something that I'm doing currently. 

I checked in debug mode - the param values -'asset' & 'filename' received are good. However, 'asset.getRendition(fileName)' throw's Null Pointer Exception. ;/

-Thanks In Advance.

[VeenaVikraman]

What is the argument you are passing to the method ? It should be the name of the rendition file for your asset like below

It will be present under your renditions folder

[smacdonald2008]

For ppl reading this thread - you can also covert an Asset- that is used in a workflow to an InputStream. See this community article for details: Modifying Digital Assets using Adobe Experience Manager Workflows

For this question - try Veena suggestion. I will test that too.

[smacdonald2008 · Accepted solution]

The below code works and was tested by getting rendition and placing it into another DAM folder.

Full example:

package com.community.test.core;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.StringWriter;

import java.util.Iterator;

import java.util.List;

import java.util.ArrayList;

import javax.jcr.Repository;

import javax.jcr.SimpleCredentials;

import javax.jcr.Node;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.IOException;

import org.apache.jackrabbit.commons.JcrUtils;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import javax.jcr.RepositoryException;

import org.apache.jackrabbit.commons.JcrUtils;

import javax.jcr.Session;

import javax.jcr.Node;

import org.osgi.framework.Constants;

import com.adobe.granite.workflow.WorkflowException;

import com.adobe.granite.workflow.WorkflowSession;

import com.adobe.granite.workflow.exec.WorkItem;

import com.adobe.granite.workflow.exec.WorkflowData;

import com.adobe.granite.workflow.exec.WorkflowProcess;

import com.adobe.granite.workflow.metadata.MetaDataMap;

//AssetManager

import com.adobe.granite.asset.api.AssetManager;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

//Sling Imports

import org.apache.sling.api.resource.ResourceResolverFactory ;

import org.apache.sling.api.resource.ResourceResolver;

import org.apache.sling.api.resource.Resource;

import com.day.cq.wcm.api.Page;

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

import org.apache.felix.scr.annotations.Property;

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

import org.apache.felix.scr.annotations.Property;

import org.apache.felix.scr.annotations.Properties;

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

//import org.osgi.service.component.annotations.Service;

import org.apache.felix.scr.annotations.Reference;

//import org.osgi.service.component.annotations.Property;

import java.util.HashMap;

import java.util.Map;

import com.adobe.granite.asset.api.Asset;

import com.adobe.granite.asset.api.Rendition;

import java.io.InputStream;  

@Component

@Service

public class GetAssetImpl implements GetAsset {

//Inject a Sling ResourceResolverFactory

@Reference

private ResourceResolverFactory resolverFactory;

/** Default log. */

protected final Logger log = LoggerFactory.getLogger(this.getClass());

public String getAsset(){

ResourceResolver resolver = null;

Map<String, Object> param = new HashMap<String, Object>();

param.put(ResourceResolverFactory.SUBSERVICE, "datawrite");

try {

        //Invoke the adaptTo method to create a Session used to create a QueryManager

        resolver = resolverFactory.getServiceResourceResolver(param);

        log.info("Cretae the Asset");

        //Use AssetManager to place the file into the AEM DAM

        AssetManager assetMgr = resolver.adaptTo(AssetManager.class);

       Asset myAsset = assetMgr.getAsset("/content/dam/we-retail/en/people/womens/women_6.jpg");

        Rendition myRen = myAsset.getRendition("/content/dam/we-retail/en/people/womens/women_6.jpg/jcr:content/renditions/cq5dam.thumbnail.140.100.png");

       InputStream is = myRen.getStream();

        //Cretae a new Asste with the Rendition

      //Use AssetManager to place the file into the AEM DAM

        com.day.cq.dam.api.AssetManager assetMgr2 = resolver.adaptTo(com.day.cq.dam.api.AssetManager.class);

       String newFile = "/content/dam/travel/test.png" ;

       assetMgr2.createAsset(newFile, is,"image/jpeg", true);

        return ("New Asset Created");

        // Return the path to the file was stored

}    

catch(Exception e)

{

e.printStackTrace();

}

return "ERROR";

}

}