import net.sf.jasperreports.engine.util.JRSwapFile; //导入依赖的package包/类
@Before
public void init() {
	JasperReportBuilder report1 = report()
		.title(cmp.text("text1"))
		.pageFooter(cmp.pageNumber());
	JasperReportBuilder report2 = report()
		.title(cmp.text("text2"))
		.pageFooter(cmp.pageNumber());
	JasperReportBuilder report3 = report()
		.title(cmp.text("text3"))
		.pageFooter(cmp.pageNumber());

	JRSwapFile swapFile = new JRSwapFile(System.getProperty("java.io.tmpdir"), 2000, 5000);
	concatenatedReport = concatenatedReport(new JasperPrintListFileHandler(System.getProperty("java.io.tmpdir"), new JRSwapFileVirtualizer(3, swapFile)));
	concatenatedReport.continuousPageNumbering();
	concatenatedReport.concatenate(report1, report2, report3);
}
 

import net.sf.jasperreports.engine.util.JRSwapFile; //导入依赖的package包/类
/**
 * Creates a virtualizer that uses a swap file.
 * <p>
 * The virtualizer will be considered the owner of the swap file.
 * 
 * @param maxSize the maximum size (in JRVirtualizable objects) of the paged in cache.
 * @param swap the swap file to use for data virtualization
 */
public JRSwapFileVirtualizer(int maxSize, JRSwapFile swap)
{
	this(maxSize, swap, true);
}