Recently I had some troubles heap error with Jasper Library in a Struts2 project.
In the first moment I think that is a issue with generation way and report size, but in some cases I checked the issue with one page report.
Somehow when the option "Stretch with Overflow" is set in a data field nearest the bottom of detail´s band and when all band´s size fill the page size causes the issue.
Steps to reproduce:
- Create a Jasper report in iReport;
- Set all the bands height to fill the max paper size;
- Create a text data field;
- Move the data field to nearest as you can to detail band´s bottom;
- Set the option "Stretch With Overflow" to this field (Like print screen attached);
- Set the Data linked to field to contains more characters that preset size (To force Overflow);
- Run preview and wait for Java Heap allocation Error;
Thanks in advance