编译报告时出错：java.lang.NoClassDefFoundError：javax / servlet / ServletOutputStream

编译报告时出错，错误是：

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: javax/servlet/ServletOutputStream 

这是代码：

 Map parameter = new HashMap(); parameter.put("customerId", notification_table.getValueAt(r, 0).toString()); ReportV sd = new ReportV(); sd.showReport(parameter); 

这是我使用的课程：

 import java.sql.*; import java.util.Map; import javax.swing.*; import static javax.swing.JFrame.EXIT_ON_CLOSE; import net.sf.jasperreports.engine.JasperCompileManager; import net.sf.jasperreports.engine.JasperFillManager; import net.sf.jasperreports.engine.JasperPrint; import net.sf.jasperreports.engine.JasperReport; import net.sf.jasperreports.swing.JRViewer; public class ReportV { Connection conn = null; void showReport(Map parameters) { try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); conn = DriverManager.getConnection("jdbc:odbc:pcn"); JasperReport report = JasperCompileManager.compileReport("recipt.jrxml"); JasperPrint print = JasperFillManager.fillReport(report, parameters, conn); JRViewer viewer = new JRViewer(print); viewer.setOpaque(true); viewer.setVisible(true); //make your JFrame visible this.add(viewer); this.setSize(300, 200); this.setVisible(true); this.setDefaultCloseOperation(EXIT_ON_CLOSE); } catch (Exception ex) { System.out.println("CAUSE: " + ex.getCause()); System.out.println("MESSAGE" + ex.getMessage()); System.out.println("LOCAL MESSAGE" + ex.getLocalizedMessage()); ex.printStackTrace(); } } } 

Answer 1

您尚未导入ServletOutputStream类。

 import javax.servlet.ServletOutputStream; 

我相信这是Java EE的一部分，所以除了标准的java jdk之外，你还需要在类路径中使用lib。