Compare two xml files and return the difference tags

[former_member750254]

Hi 7a519509aed84a2c9e6f627841825b5a , engswee.yeoh

I am trying to find out the difference between two xml files and return the difference tags.

To Achieve this I am storing the xml files in Datastore and to find out the difference I am using the below Groovy script.

import com.sap.gateway.ip.core.customdev.util.Message
//Imports for DataStoreService-class
import com.sap.it.api.asdk.datastore.*
import com.sap.it.api.asdk.runtime.*
/*import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.output.XMLOutputter;*/
import org.jdom2.*;
import org.xmlunit.diff.*;
Message processData(Message message)
{
def service = new Factory(DataStoreService.class).getService()

//Check if valid service instance was retrieved
if( service != null) {
//Read data store entry via id
def dsEntry = service.get("MetadataStorage","Metadata")
def result = new String(dsEntry.getDataAsArray())
//message.setBody(body)
def dsEntry1 = service.get("MetadataCurrent","CurrentData")
def result1 = new String(dsEntry1.getDataAsArray())
//message.setBody(body)

DifferenceEngine diff = new DOMDifferenceEngine();
diff.addDifferenceListener(new ComparisonListener() {
        public void comparisonPerformed(Comparison comparison, ComparisonResult outcome) {
            Assert.fail("found a difference: " + comparison);
        }
    });
diff.compare(result, result1);
}
   // return message
}

Below is the Error I am Getting. Kindly let me know if we are missing anything/ suggest me how to get the difference between two xml files.

Note: I have imported JDOM and XMLUNIT Jar files.Error Details

javax.script.ScriptException: java.lang.Exception: java.lang.NullPointerException: Cannot invoke method getDataAsArray() on null object@ line 22 in compareXML.groovy, cause: java.lang.NullPointerException: Cannot invoke method getDataAsArray() on null object 

[MortenWittrock]

Hi

If you are relatively new to Groovy scripting, I think you should do yourself a favour and make the code simpler. Don't try to do everything at once.

For instance, instead of trying to extract the documents from the data store in code, retrieve them using two data store Get operations and store them in properties before the script step, which you can then access in the code. This has the added benefit that you are not using undocumented APIs.

Then ask yourself if you really need the differences between the documents, or only need to know whether they are identical. The latter is a lot simpler and in that case, you probably need the org.custommonkey.xmlunit.Diff class.

Then store the result of the comparison (hopefully just true or false) in a property and remember to return the Message object from the method.

If you are indeed new to scripting and Groovy, there's no way around spending some time on learning the basics. Otherwise it is going to be a very frustrating experience, when it could instead be a lot of fun.

Regards,

Morten