Applet加载错误-碧玉报告

Question

I have encountered an error with my applet that I can not figure out solution. I am loading my java applet which encompass a simple jasper viewer in it. When the applet is loaded it throws following exception:

SEVERE: Servlet.service() for servlet JasperReportServlet threw exception
java.lang.ClassNotFoundException: org.apache.commons.collections.ReferenceMap
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    at net.sf.jasperreports.extensions.DefaultExtensionsRegistry.<init>(DefaultExtensionsRegistry.java:96)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at java.lang.Class.newInstance0(Class.java:355)
    at java.lang.Class.newInstance(Class.java:308)
    at net.sf.jasperreports.engine.util.ClassUtils.instantiateClass(ClassUtils.java:59)
    at net.sf.jasperreports.extensions.ExtensionsEnvironment.createDefaultRegistry(ExtensionsEnvironment.java:80)
    at net.sf.jasperreports.extensions.ExtensionsEnvironment.<clinit>(ExtensionsEnvironment.java:68)
    at net.sf.jasperreports.engine.util.JRStyledTextParser.<clinit>(JRStyledTextParser.java:76)
    at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:182)
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:77)
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:87)
    at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:57)
    at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:142)
    at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:78)
    at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:624)
    at com.dbhl.app.report.generator.JobUpdateGenerator.getJasperPrintObject(JobUpdateGenerator.java:279)
    at com.dbhl.app.report.JasperReportServlet.processJobUpdate(JasperReportServlet.java:153)
    at com.dbhl.app.report.JasperReportServlet.getJasperPrintObjectByLedgerType(JasperReportServlet.java:79)
    at com.dbhl.app.report.JasperReportServlet.service(JasperReportServlet.java:50)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)

Below is my applet configuration and I am loading applet using standard java deployment toolkit.

<script type="text/javascript" src="<%=basePath%>js/deployJava.js">
</script>

<script>
  var user = '<%=request.getParameter("user")%>';

  var attributes = {
    code : 'applet.EmbeddedViewerApplet.class',
    archive : '<%=basePath%>resources/appletviewer.jar,<%=basePath%>resources/jasperreports-applet-4.0.0.jar,<%=basePath%>resources/jasperreports-4.0.0.jar,<%=basePath%>resources/commons-collections-3.2.1.jar,<%=basePath%>resources/commons-logging-1.0.4.jar,<%=basePath%>resources/commons-beanutils-1.8.0.jar,<%=basePath%>resources/commons-digester-1.7.jar,<%=basePath%>resources/commons-javaflow-20060411.jar,<%=basePath%>resources/org-netbeans-core.jar',
    width : "100%",
    height : 600
  };

  var parameters = {
    fontSize : 16,
    REPORT_URL : '<%=basePath%>servlet/JasperReportServlet?startDate=<%=request.getParameter("startDate")%>&endDate=<%=request.getParameter("endDate")%>&user=' + user + '&reportType=<%=request.getParameter("reportType")%>'
  };

  var version = '1.4';
  deployJava.runApplet(attributes, parameters, version);
</script>

All the jars I need in the applet exist in the resource folder of my webroot, which are

• appletviewer.jar
• commons-beanutils-1.8.0.jar
• commons-collections-3.2.1.jar
• commons-digester-1.7.jar
• commons-javaflow-20060411.jar
• commons-logging-1.0.4.jar
• jasperreports-4.0.0.jar
• jasperreports-applet-4.0.0.jar
• org-netbeans-core.jar

All the jars are signed today, so no validity expires. I have double checked everything, but it always shows the above error. In iReport I can view the report and it is compiled to jasper object with no error.

The java console from control panel

I checked in the temp cache that the collections file is downloaded successfully and in the above console log it shows that the jars are successfully downloaded to the host computer. Why is the ClassNotFoundException happening?

Answer 1

错误来自服务器端，我在跟踪控制台日志后才知道，在我的服务器类路径comons-collections中丢失了，我添加了它，并且一切运行正常。