[MSHARED-269] File locking problem on the file associated to 'getOutpuName()', even if the report is external

[jira-importer]

Baptiste Gaillard opened MSHARED-269 and commented

Creating a Maven Report Mojo which extends the AbstractMavenReport class and returns 'true' in the 'isExternalReport' locks the file associated to the name returned by the 'getOutputName()' function of the Mojo.

The locking problems appears inside the 'executeReport(...)' function of the Mojo, I'm not sure if its normal or not but I have to delete this file to generate a documentation with JSDuck (Javascript documentation).

A full description of the problem is provided here http://www.mail-archive.com/users@maven.apache.org/msg127863.html

I provide two Maven projects which allow to reproduce the problem :

• bug-maven-plugin : A very simple plugin which only tries to delete the 'index.html' file, that's to say the name provided by the 'getOutputName()' function.
• bug-site-project : A very simple project which uses the 'bug-maven-plugin' Reporting Plugin, running 'mvn site' on it allow to show the file locking problem I encounter.

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Affects: maven-reporting-impl-2.2

Attachments:

• FileLock.zip (5.16 kB)

Issue Links:

• DOXIASITETOOLS-103 Don't create outputFile in case of an external report

[jira-importer]

Olivier Lamy commented

did you try with last doxia snapshots ?
I try to find possible lock but no luck (and impossible for me to reproduce as I use an os without issue for files locking :-) )

[jira-importer]

Baptiste Gaillard commented

Hi Olivier and sorry for the delay, I had a lot of work...

When I created this issue I was using Windows 7 and calling Maven using the M2Eclipse plugin (inside Eclipse 4.2.1).

Now I'm using Windows 8, running 'mvn site' on the sample project 'bug-site-maven' also causes the error :

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.0:site (default-site) on project bug-site-project:
Error during page generation: Error rendering Maven report: Fail to delete the previously generated 'C:\dev_tools\Sources\workspace\bug-site-project\target\site\bug\index.html' ! -> [Help 1]

I believe this problem is not due to M2Eclipse because I also encounter it outside Eclipse (using the command line).

I tried to update all the dependencies I had in the two sample projects I've provided.

Now in the 'bug-maven-project' I use the following deps:

• org.apache.maven:maven-plugin-api:3.1-SNAPSHOT
• org.apache.maven.reporting:maven-reporting-impl:2.3-SNAPSHOT
• org.apache.maven.shared:maven-shared-utils:0.3-SNAPSHOT
• org.apache.maven.doxia:doxia-sink-api:1.4-SNAPSHOT

In the 'bug-site-project' I use the following site plugins :

• org.apache.maven.plugins:maven-project-info-reports-plugin:2.7-SNAPSHOT
• org.apache.maven.plugins:maven-site-plugin:3.3-SNAPSHOT
• com.gomoob.maven.plugins:bug-maven-plugin:1.0

Is this the right thing to do to use the last doxia snapshot deps ?

The use of those SNAPSHOT deps has no effect and the file lock is still there...

If you do not encounter this bug under a UNIX machine I suspect something like a Class Loader locking problem.

This is common undex Windows Java VM and perhaps the 'index.html' created by the Maven site plugins is handled by a URLClassloader somewhere ? (http://docs.oracle.com/javase/7/docs/api/java/net/URLClassLoader.html)

Sadly I do not have much more time to study this problem in details today.

As I'm not a Maven plugin expert can you provide me guides to help me know how can I retrieve references to the class loaders which are used during the execution of a 'mvn site' command ?

I'll try to see which on of the class loaders handles the 'index.html' file...

Thanks,

Baptiste

[jira-importer]

Robert Scholte commented

I can still reproduce it, though I think it is an Doxia issue. http://maven.apache.org/doxia/doxia-sitetools/doxia-site-renderer/xref/org/apache/maven/doxia/siterenderer/DefaultSiteRenderer.html#L307 looks good to me, although I'm interested in what the WriterFactory actually creates and if the close() call has any effect.

[jira-importer]

Robert Scholte commented

Fixed in Doxia Core with DOXIASITETOOLS-103.
Root cause was the FileWriter, which creates the outputFile since the idea is that with Sink calls you build up the document. I've decided that in case of an external report no outputfile is created. The MavenReport itself is responsible for creating it.
There's no change in this project required. Once doxia-sitetools is released, the maven-site-plugin just need to update the dependencies to that version.