Formation of a link to a file for download by the user on CMMN

Camunda 7 Topics Discussion & Questions
1

Hello, all happy new year 2020! I am trying to download a file from the INVOICE_DOCUMENT link (the file was previously uploaded there) in a new instance of the process. It turned out to save only the data on the file and its name and type separately. How can I combine these values on a js/html page or in Java code, so that the user can download the source file in different instances (through CaseInstance I call new instances of processes, when starting new instances I use the class to store the necessary information). Thank you for your attention!

2

A solution was found (without using the REST API, at the request of the task). The algorithm is as follows:

  1. Get information about the file through the html form INVOICE_DOCUMENT

  2. We transform the data into an array of bytes and read the name of the file with the extension.

  3. We write the array to the file.
    To generate the link, we use the copied file and, based on its data, create the download link in the INVOICE_DOCUMENT.
    The solution is not the best, but still.
    Hope it helps someone.
    Get file and info:

     ByteArrayInputStream fileData = null;
 FileValueImpl fileMetadata = null;
 fileMetadata = (FileValueImpl)execution.getVariableLocalTyped("INVOICE_DOCUMENT");   
 fileData = (ByteArrayInputStream) execution.getVariable("INVOICE_DOCUMENT");
 FileOutputStream fileOut = null;
 int size_file = fileData.available();
 fileOut = new FileOutputStream(fileMetadata.getFilename());
 byte[] data = new byte[fileData.available()];
 fileData.read(data);  
 fileOut.write(data);

Generation link:

    FileValue typedFileValue = Variables
    .fileValue(fileMetadata.getFilename())
    .file(new File(fileMetadata.getFilename()))
    .mimeType(fileMetadata.getMimeType())
    .encoding(fileMetadata.getEncoding())
    .create();
     execution.setVariable("INVOICE_DOCUMENT", typedFileValue);
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