ConversionInputException on a complex web application

Question

I've got this ConversionInputException when I invoke both execute() or schedule() methods on a specific converter.

I think the code it's correct because if I execute the code as a simple java application it work perfectly with the same file as input.

When I deploy the code as a jar and call the code from a complex web application I always had this ConversionInputException .

I've also tried with the InputStream insted of File object but I've got the same exception.

I'm able to open the file with MS-Word without any problem, and I also I'm able to convert it in a standalone java application running the same code.

Here is the code I use

private void convert(File inputFile, File outputFile) {
     boolean conversion=false;
     IConverter converter=com.b80.common.d2.wf.utility.CustomConverter.getInstance().getConverter();
     conversion = converter.convert(inputFile).as(DocumentType.MS_WORD)
                          .to(outputFile).as(DocumentType.PDF)
                          .prioritizeWith(1000).execute();
}

And the converter class it's developed as follows - I had to use synchronized methods because that instance of the converter could be accessed by multiple thread on the server:

import java.io.File;
import java.util.concurrent.TimeUnit;
import com.documents4j.api.IConverter;
import com.documents4j.job.LocalConverter;

public class CustomConverter {
    private static IConverter converter=null;
    private static final String CONVERSION_FOLDER="E:\\temp\\document4j";

    private static CustomConverter instance = null;
    private CustomConverter() {
      // Exists only to defeat instantiation.
    }
    public static synchronized CustomConverter getInstance() {
      if(instance == null) {
         instance = new CustomConverter();
      } 
      return instance;
   }

    public synchronized IConverter getConverter() {
    if(converter==null || !converter.isOperational()) {
        converter=LocalConverter.builder().baseFolder(new File(CONVERSION_FOLDER)).workerPool(20, 25, 5, TimeUnit.MINUTES)
                .processTimeout(10, TimeUnit.MINUTES)
                .build(); 
    }       
    return converter;
  }
}

Here is the StackTrace, obviously the exception is on the convert() function.

2016-04-28 16:52:21,483 ERROR [STDERR] (http-0.0.0.0-9080-1) com.documents4j.throwables.ConversionInputException: The input file seems to be corrupt
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.util.Reaction$ConversionInputExceptionBuilder.make(Reaction.java:159)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.util.Reaction$ExceptionalReaction.apply(Reaction.java:75)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.conversion.ExternalConverterScriptResult.resolve(ExternalConverterScriptResult.java:70)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.conversion.ProcessFutureWrapper.evaluateExitValue(ProcessFutureWrapper.java:48)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.conversion.ProcessFutureWrapper.get(ProcessFutureWrapper.java:36)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.conversion.ProcessFutureWrapper.get(ProcessFutureWrapper.java:11)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at com.documents4j.job.AbstractFutureWrappingPriorityFuture.run(AbstractFutureWrappingPriorityFuture.java:78)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
2016-04-28 16:52:21,484 ERROR [STDERR] (http-0.0.0.0-9080-1)    at java.lang.Thread.run(Thread.java:662)

I analyzed more deeply the code and added some logs into word_convert.vbs, I obtained an error message like this:

Error # 424 Object required

I know it's a little bit generic message, but I hope it could help a little more.

Answer 1

I am the author of documents4j and generally, I think this is a user problem as I have run documents4j successfully from many environments and never encountered such a problem.

It is difficult to say what the problem is as I do not know what exactly it is that makes your web application complex . As the response suggests that your file is corrupt and since the converter does work without the complex part of your application, I assume that you do corrupt the file at some point.

What I can suggest you to try for debugging:

1. Implement a pseudo converter that only receives the byte array and sends a dummy file back. Check the received bytes to be equal to the bytes of the original file. Maybe you are cutting off some values?
2. Reduce your application step-by-step to the simple application that works and see what step in the process breaks your premise.