Can't open or delete a pdf report generated within a Django 5.0 application

[PabrodzamDEV]

Greetings! First and foremost, I hope you will understand that I am a novice in the field of software development, particularly when it comes to web applications. Also, English is not my native language.

I am using PyReportJasper within the context of a Django 5.0 web application, and I am able to successfully generate and save the report as a PDF file. However, I am facing an issue where I encounter a java.io.IOException when attempting to open or delete the file from my file system. Interestingly, I am able to preview the file within my PyCharm IDE. The only way I can open or delete the file is by shutting down the local Django server.

I understand this is not a problem with the library, since I generated reports outside the django application in simple .py files and this issue did not arise, but since there are people way more experienced than me here I thought posting here is my best shot at finding a solution :)

I have included my code below, and I will also provide some screenshots to further illustrate the problem.

@admin.action(description="Generate report with the selected poems")
def generate_monthly_poems_report(modeladmin, request, queryset):
    # Get the earliest date
    date_range = queryset.aggregate(
        earliest_date=Min('updated_at')
    )

    earliest_date_year = int(date_range['earliest_date'].strftime("%Y"))
    earliest_date_month = int(date_range['earliest_date'].strftime("%m"))

    input_file = os.path.join(JRXML_DIR, 'poems.jasper')
    output_file = os.path.join(REPORTS_DIR,
                               f'monthly_poems {earliest_date_year}-{earliest_date_month}_{timezone.now().strftime("%H%M%S")}')
    pyreportjasper = PyReportJasper()
    conn = {
        'driver': 'mysql',
        'username': 'root',
        'password': 'root',
        'host': 'localhost',
        'database': 'dickinsonproject',
        'port': '3306',
        'jdbc_driver': 'com.mysql.cj.jdbc.Driver',
        'jdbc_url': 'jdbc:mysql://localhost:3306/dickinsonproject'
    }
    pyreportjasper.config(
        input_file,
        output_file,
        output_formats=["pdf"],
        parameters={'YEAR': earliest_date_year, 'MONTH': earliest_date_month, 'CONTEXT': JRXML_DIR},
        db_connection=conn
    )
    pyreportjasper.process_report()
    output_file = output_file + '.pdf'
    if os.path.isfile(output_file):
        print('Report generated successfully!')

[PabrodzamDEV]

Okay, so after an incredible amount of hours and frustration I got things working!

I just closed output_stream at the end of the export_pdf() method from the Report class:

report.py

def export_pdf(self):
    output_stream = self.get_output_stream('.pdf')
    output_stream_pdf = self.get_output_stream_pdf()
    output_stream_pdf.writeTo(output_stream)
    output_stream_pdf.flush() # if no buffer used, it can be ignored.
    output_stream_pdf.close()
    output_stream.close() # I closed output_stream