OneThousandAndOne!! bug found - JRDataProvider

[kjhuebner]

In attempting to bind and test connection to a JRDataProvider class within IReport, I get an error message which reads:

 

"TestProvider" is not a subclass of "net.sf.jasperreports.engine.JRDataSourceProvider"

 

First, the JRDataSourceProvider is an interface. You cannot have a subclass of an interface.

 

More importantly, my TestProvide class implements this interface correctly. I compile it and make it available in IReport classpath. Here's a sample snippet:

 

public class TestDataSourceProvider implements JRDataSourceProvider

 

See doc for more details.

 

THanks,

Ken

[file name=JRDataSourceProvider_error.doc size=64512]http://www.jasperforge.org/components/com_joomlaboard/uploaded/files/JRDataSourceProvider_error.doc[/file]

[Giulio Toffoli]

Hi Ken,

 

I don't know why you get this error...

I tried your classes and iReport recognizes it as a DataSource provider without problems.

 

 

I got a couple of problems using your datasource (but I'm sure you have to finish it).

 

I used iReport 1.2.5 and I compiled your files stripping out the package (only to speed up my test).

 

 

Problem 1:

the getFields method in the TestDataSourceFactory return two times the same field (Address), this becuase you do not make a new field, but simply

change the attributes of the same object:

 

Code:

jrField.setName("Name"«»);
    jrField.setValueClass(String.class);
    list.add(jrField);
    
// You should put here a:
// jrField = new new JRDesignField();

    jrField.setName("Address"«»);
    jrField.setValueClass(String.class);
    list.add(jrField);

 

Problem 2:

there is a classCastException on line 143:

 

Code:

[code] map= (Map)map.get("Tasks"«»);

 

this returns a List of Map objects, not a single Map.

 

Code:

[code] Error filling print... ENTERED TestDataSourceFactory.getTheDatasource() ENTERED TestDataSource() CONSTRUCTOR ENTERED TestDataSource getFieldValue() java.lang.ClassCastException: java.util.ArrayList at TestDataSource.getFieldValue(TestDataSource.java:143) at net.sf.jasperreports.engine.fill.JRFillDataset.setOldValues(JRFillDataset.java:788) at net.sf.jasperreports.engine.fill.JRFillDataset.next(JRFillDataset.java:752) at net.sf.jasperreports.engine.fill.JRBaseFiller.next(JRBaseFiller.java:1019) at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:126) at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:758) at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:685) at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:89) at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:601) at it.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:742) at java.lang.Thread.run(Thread.java:595) Print not filled. Try to use an EmptyDataSource...!

 

Finally, the message (wrong, you right) is generated from the following code:

 

Code:

[code] Object obj = Class.forName((String)jTextFieldJRDataSourceProvider.getText().trim(), true, MainFrame.getMainInstance().getReportClassLoader()).newInstance(); if (!(obj instanceof net.sf.jasperreports.engine.JRDataSourceProvider)) { JOptionPane.showMessageDialog((Component)getParent(),""" + jTextFieldJRDataSourceProvider.getText() + "" is not a subclass ofnnet.sf.jasperreports.engine.JRDataSourceProvider.","Error",JOptionPane.ERROR_MESSAGE); return; }

 

Don't ask me why iReport thinks that your class is not an instance of JRDataSourceProvider on your machine...

 

 

Giulio

[kjhuebner]

Hi Giulio,

I started up my machine again this morning and tried out my custom JRDataSourceProvider again. It worked this time! No exception appeared when I clicked Test.

 

I've ran across quite a few problems like this before.

There must be many refresh-related bugs in IReport. I think my strategy going forward is to shutdown and restart IReport whenever I see weird behaviour. At least until you guys fix the bugs I'm seeing!

 

Thanks again,

Ken

[djsiders]

Any changes made in your provider class are only loaded into Ireports at startup. Guessing it reads the classpath setting and loads all. I think IReports is expecting a completed and tested data provider, and isn't really meant to be a development tool for that (although it would be nice)