What can I do with 0k or empty files?

Question

Hello.  How can I get Qvera to read empty files?

 

The project I'm working on is for HL7 messages being read from a folder but sometimes a 0k file will be sent and I need a way for Qvera to read them then generate an error with the file name.  As best as I can tell, Qvera ignores empty files and leaves them in the source folder without generating an error.

 

Thank you!  I am very new to Qvera and this is my first posted question.

Answer 1

Very good question.  You are correct, QIE ignores empty files since they don't actually contain a message.  For your situation, I would use a scheduled script to monitor the directory for empty files.

Select the green source node, and select the Scheduled Scripts tab.

Click Insert to create a new Scheduled Script.  Set the following fields:

Name:

Error Empty Files

CRON String: 

0 0 * * * *

Script: 

var srcDirectoryPath = "C:\\Qvera\\In\\";

var extension = "txt";

 

File = java.io.File;

var FileUtils = org.apache.commons.io.FileUtils;

 

function isFileEmpty(fileName) {

   var FileInputStream = java.io.FileInputStream;

   var fis;

   var empty = false;

   try {

      fis = new FileInputStream(new File(fileName));

      empty = fis.read() == -1;

   } finally {

      try {

         fis.close();

      } catch (err) {

         qie.info('Failed to close file: ' + fileName);

      }

   }

   return empty;

}

 

var timeThreshhold = new java.util.Date().getTime() - (3 * 60 * 1000); // 3 minutes old

var extensions = java.lang.reflect.Array.newInstance(java.lang.String, 1);

extensions[0] = new java.lang.String(extension);

var srcDirectory = new File(srcDirectoryPath);

qie.debug('Script looking in ' + srcDirectoryPath + ', for extension \'txt\', and threshhold of ' + timeThreshhold);

 

var listFiles = FileUtils.convertFileCollectionToFileArray(FileUtils.listFiles(srcDirectory, extensions, false));

qie.debug('found ' + listFiles.length + ' files!');

for (var i = 0; i < listFiles.length; i++) {

   var currentFile = listFiles[i];

   qie.debug(currentFile + ', older?' + FileUtils.isFileOlder(currentFile, timeThreshhold) + ', empty?' + isFileEmpty(currentFile.getAbsolutePath()));

   if (FileUtils.isFileOlder(currentFile, timeThreshhold) && isFileEmpty(currentFile.getAbsolutePath())) {

      var fileName = currentFile.getName();

      qie.warn('Empty File Found: ' + fileName);

      qie.addInboundMessage('Empty File Found: ' + fileName, fileName);

      if (!FileUtils.deleteQuietly(currentFile)) {

         qie.error('Failed to delete empty file: ' + fileName);

      }

   }

}

It should look something like this:

 

My test channel is looking in for files C:\Qvera\In\*.txt.  In your script, you will need to change the values for srcDirectoryPath, and the extension.

 

This script will do the following:

1. Run at the top of the hour (based on the CRON String)

2. Find files in the srcDirectoryPath, with the extension which are at least 3 minutes old

3. Add a new message of "Empty File Found: " followed by the fileName

4. Remove the empty file from the directory

This was a lot of fun making this solution. :)  I hope you enjoy it.