How to resolve this: pyreportjasper: ImportError: DLL load failed while importing jpy: The specified module could not be found

Question

I want to use Jasper Reports with a python-flask app.

I have followed the installation instructions on this page: https://pypi.org/project/pyreportjasper/

It fails on the line import jpy, I am getting the error:

ImportError: DLL load failed while importing jpy: The specified module could not be found.

I am using 32 bit python Python: 3.8.6rc1. 32 bit JDK: javac 1.8.0_261

When I run pip install pyreportjasper, it says: Requirement already satisfied: jpy in c:\users....

Any ideas?

Answer 1

It seems that you need to import jpyutil and then initialize the JVM prior to calling import jpy. The following fixed this error for me. One step closer.

import jpyutil
jpyutil.init_jvm(jvm_maxmem='512M')
import jpy

UPDATE: so while the above statement is true, it doesn't directly address the issue of running the example code at the project page: https://pypi.org/project/pyreportjasper/

As I dug into the code I found that jasperpy.py is attempting to import jpy BEFORE the __init__ method is run and therefore BEFORE the JVM is initialized via the jpyutil.init_jvm() method call. So I edited jasperpy.py and moved import jpy from line 14 to line 56, directly after the call to jpyutil.init_jvm() and before the call to jpy.get_type('java.io.File') and I am able to successfully run Jasper reports from python via the example code shown. Here is what my jasperpy.py looks like now.

# -*- coding: utf-8 -*-
# GNU GENERAL PUBLIC LICENSE
#
# Copyright (c) 2020 Jadson Bonfim Ribeiro <[email protected]>
#

import os
import subprocess
import re
import xml.etree.ElementTree as ET

import tempfile
import jpyutil
#import jpy
import json
from requests import Request, Session

FORMATS = (
    'pdf',
    'rtf',
    'xls',
    'xlsx',
    'docx',
    'odt',
    'ods',
    'pptx',
    'csv',
    'html',
    'xhtml',
    'xml',
    'jrprint',
)

EXECUTABLE = 'jasperstarter'

class JasperPy:

    _FORMATS_JSON = ('pdf')

    _FORMATS_METHODS_REQUEST = ('GET', 'POST', 'PUT')

    def __init__(self, resource_dir=False, jvm_maxmem='512M', jvm_classpath=None):
        self.WINDOWS = True if os.name == 'nt' else False
        self.SCRIPT_DIR = os.path.abspath(os.path.dirname(__file__))
        self.LIBS = os.path.join(self.SCRIPT_DIR, 'jasperstarter', 'lib')
        if not os.path.isdir(self.LIBS):
            raise NameError('Unable to find lib in {0}'.format(self.LIBS))
        self.CLASSPATH = os.path.join(self.LIBS, 'jasperstarter.jar')
        if not os.path.exists(self.CLASSPATH):
            raise NameError('Unable to find jasperstarter in {0}'.format(self.LIBS))
        if jvm_classpath is None:
            jpyutil.init_jvm(jvm_maxmem=jvm_maxmem, jvm_classpath=[self.CLASSPATH])
        else:
            jpyutil.init_jvm(jvm_maxmem=jvm_maxmem, jvm_classpath=[self.CLASSPATH, jvm_classpath])
        # IMPORT jpy HERE AFTER init_jvm
        import jpy
        self.jvFile = jpy.get_type('java.io.File')
        self.jvArrays = jpy.get_type('java.util.Arrays')
        self.jvReport = jpy.get_type('de.cenote.jasperstarter.Report')
        self.jvConfig = jpy.get_type('de.cenote.jasperstarter.Config')
        self.jvDsType = jpy.get_type('de.cenote.jasperstarter.types.DsType')
        self.jvApplicationClasspath = jpy.get_type('de.cenote.tools.classpath.ApplicationClasspath')
        self.jvHashMap = jpy.get_type('java.util.HashMap')
        self.jvLocale = jpy.get_type('java.util.Locale')
        self.jvJasperFillManager = jpy.get_type('net.sf.jasperreports.engine.JasperFillManager')
        self.jvDb = jpy.get_type('de.cenote.jasperstarter.Db')
        self.jvJsonQueryExecuterFactory = jpy.get_type('net.sf.jasperreports.engine.query.JsonQueryExecuterFactory')
        self.jvJasperExportManager = jpy.get_type('net.sf.jasperreports.engine.JasperExportManager')
.
.
.
.

This file is located in your Python directory under Lib\site-packages\pyreportjasper-2.0.2-py3.8.egg\pyreportjasper. While this is currently a hack to make it work, there obviously needs to be a fix to the package which I will attempt to address on the pyreportjasper github page.