我正在处理 Jasper 报告。我尝试生成 excel 文件，但下面的代码出现异常。
JasperReport jasperReport = JasperCompileManager.compileReport("C:\\jasper files\\report1.jrxml");
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, new HashMap(), new JREmptyDataSource());
JRXlsExporter exporterXLS = new JRXlsExporter();
exporterXLS.setParameter(JRXlsExporterParameter.JASPER_PRINT, jasperPrint);
exporterXLS.setParameter(JRXlsExporterParameter.OUTPUT_STREAM, "sample1.xls");
exporterXLS.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.TRUE);
exporterXLS.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND, Boolean.FALSE);
exporterXLS.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS, Boolean.TRUE);
exporterXLS.exportReport();
例外是Caused by: java.lang.ClassNotFoundException: org.apache.poi.ss.usermodel.Sheet
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 1 more