How to merge two pdf documents into a single report in JasperReports?

Question

I am new to JasperReports. I can create a simple PDF document with Javabean datasource. In my project I have created two separate pdf document with separate javabean datasou

Answer 1

Lahiru Nirmal's answer was simple and to the point. Here's a somewhat expanded version that also copies styles and other things (not all of which I'm positive are crucial).

Note that all of the pages are of the same size.

public static JasperPrint createJasperReport(String name, JasperPrint pattern)
{
    JasperPrint newPrint = new JasperPrint();
    newPrint.setBottomMargin(pattern.getBottomMargin());
    newPrint.setLeftMargin(pattern.getLeftMargin());
    newPrint.setTopMargin(pattern.getTopMargin());
    newPrint.setRightMargin(pattern.getRightMargin());
    newPrint.setLocaleCode(pattern.getLocaleCode());
    newPrint.setName(name);
    newPrint.setOrientation(pattern.getOrientationValue());
    newPrint.setPageHeight(pattern.getPageHeight());
    newPrint.setPageWidth(pattern.getPageWidth());
    newPrint.setTimeZoneId(pattern.getTimeZoneId());

    return newPrint;
}

public static void addJasperPrint(JasperPrint base, JasperPrint add)
{
    for (JRStyle style : add.getStyles())
    {
        String styleName = style.getName();
        if (!base.getStylesMap().containsKey(styleName))
        {
            try
            {
                base.addStyle(style);
            }
            catch (JRException e)
            {
                logger.log(Level.WARNING, "Couldn't add a style", e);
            }
        }
        else
            logger.log(Level.FINE, "Dropping duplicate style: " + styleName);
    }

    for (JRPrintPage page : add.getPages())
        base.addPage(page);

    if (add.hasProperties())
    {
        JRPropertiesMap propMap = add.getPropertiesMap();
        for (String propName : propMap.getPropertyNames())
        {
            String propValue = propMap.getProperty(propName);
            base.setProperty(propName, propValue);
        }
    }

    if (add.hasParts())
    {
        PrintParts parts = add.getParts();
        Iterator> partsIterator = parts.partsIterator();
        while (partsIterator.hasNext())
        {
            Entry partsEntry = partsIterator.next();
            base.addPart(partsEntry.getKey(), partsEntry.getValue());
        }
    }

    List bookmarks = add.getBookmarks();
    if (bookmarks != null)
        for (PrintBookmark bookmark : bookmarks)
            base.addBookmark(bookmark);
}

Then, to use it:

JasperPrint combinedPrint = createJasperReport("Multiple Reports",
    print1);
for (JasperPrint addPrint : new JasperPrint[] { print1, print2, print3 })
    addJasperPrint(combinedPrint, addPrint);

// Now do whatever it was you'd do with the JasperPrint.
String combinedXml = JasperExportManager.exportReportToXml(combinedPrint);

I see JasperReports now has a newer "Report Book" feature that might be a better solution, but I haven't used one yet.