[JCR-3984] Overriding of processResponseBody, and using getResponseBodyAsDocument(), causes a NullPointerException

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.12.1
• Component/s: jackrabbit-webdav
• Environment: Oracle_JVM 1.8.0_91, jackrabbit-webdav-2.12.1
• Assignee: Unassigned
• Reporter: Ankush Mishra
• Created: 04/Jun/16 18:51
• Updated: 05/Jun/16 02:22

Description

So, since, WebDAV-Sync Report Method RFC 6578 hasn't been included yet. I decided to go along and make a method, which extends ReportMethod. I had to override processResponseBody in DavMethodBase because RFC 6578 overrides the MultiStatus element to include other than MultiStatusResponses but also a sync token. For Example:

<D:multistatus>
<D:response>...</D:response>
<D:response>...</D:response>
<D:sync-token> ... </D:sync-token>
</D:multistatus>

To parse I need to getResponseBodyasDocument. But problem lies in the fact that it can't be used more than once, by definition. Thus, I have to override the Sync Method class to also include a private multistatus variable, where as, if this wasn't done and DavMethodBase.processResponseBody was used, then it would yield a NullPointerException.

The solution to this, I found is that in the function DavMethodBase.getResponseBodyasDocument has a check for responseDocument, but responseDocument is never set after reading

DavMethodBase.java

getResponseBodyasDocument(){
if (responseDocument != null)

Unknown macro: { return responseDocument; // response has already been read }

....
....
InputStream in = getResponseBodyAsStream();
if (in != null) {
// read response and try to build a xml document
try {
return DomUtil.parseDocument(in);

which simply put returns the document without setting it. A minor update to this solution would be:

DavMethodBase.java

getResponseBodyasDocument(){
if (responseDocument != null)

Unknown macro: { return responseDocument; // response has already been read }

....
....
InputStream in = getResponseBodyAsStream();
if (in != null) {
// read response and try to build a xml document
try {
responseDocument = DomUtil.parseDocument(in);
return responseDocument;

Hopefully, this makes sense and is updated. in DavMethodBase#getResponseBodyasDocument