我正在开发基于Struts 2的应用程序，该应用程序在Chrome和Mozilla firefox中运行良好，但是在IE 11中发生了什么，当我按下IE的后退按钮时，它首先显示了如下所示的异常
org.apache.jasper.JasperException: An exception occurred processing JSP page /jsp/ComparativeSiteAnalysis.jsp at line 97
94: <td><table width="100%" border="0" cellpadding="0" cellspacing="0">
95: <tr>
96: <td width="19%" class="chart_head_1"> </td>
97: <td width="81%" colspan="7" class="chart_head_1"><%=((String)request.getAttribute("divName")).replace(" "," ")%> <%= manager.getValue(langSelected+AppConstants.HEADING_COMPARATIVE_CHART) %></td>
98: <td align="right" ><a href="#" onclick="back();" class="back_link"><img src="./images/Right Arrow.png" width="12" height="12" border="0" /> <%= manager.getValue(langSelected+AppConstants.BACK) %></a></td></tr>
99: <tr>
100: <td class="chart_head_2" colspan="9">
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:154)
org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:361)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:265)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
org.displaytag.filter.ResponseOverrideFilter.doFilter(ResponseOverrideFilter.java:125)
root cause
java.lang.NullPointerException
org.apache.jsp.jsp.ComparativeSiteAnalysis_jsp._jspService(ComparativeSiteAnalysis_jsp.java:214)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
后退代码
@Override
public String getComparativeSiteAnalysis(Integer divId, String lang, int selectedYear) {
// System.out .println("getComparativeSiteAnalysis lang="+lang);
maxSizeSiteName = "";
if (divId != null) {
List<Frequency> freqList = null;
List<Site> sites = null;
int year = -1;
try {
//PLEANTY OF CODE
} catch (CustomException e) {
logger.error("Error in getComparativeSiteAnalysis Method", e);
}
if (sites == null || sites.isEmpty()) {
return "";
}
dataCount = sites.size();
// System.out.println("dataCount:"+dataCount);
List<String> colList = new ArrayList<String>();
Collections.sort(sites, new UniversalComparator("isStatus", 1));
for (Iterator<Site> iterator = sites.iterator(); iterator.hasNext();) {
site = iterator.next();
if (site.getName().length() > maxSizeSiteName.length()) {
maxSizeSiteName = site.getName();
}
int naSiteDataCount = 0;
logger.debug("SITE NAME===>>" + site.getName());
Utility.getInstance().computeSite(site, true, null, false, null, year);
// System.out.println(" sitename: "+site.getName()+" semi annual compliance:
// "+site.getSemiAnnualCompliance());
String link = "JavaScript:getSiteWiseMonthlyChapterAnalysis('"
+ StringEscapeUtils.escapeXml(site.getName()) + "'," + site.getId() + ","
+ manager.getValue(AppConstants.MONTHLY) + ",'" + monthlyFreqName + "')";
rowList.add(site.getName());
siteComparativeChart = utility.addHeapMapDataSetNode(site.getName(), monthlyFreqName,
String.valueOf(roundTwoDecimals(site.getMonthlyCompliance())), link, siteComparativeChart,
site.getComparativeColorMonthly());
int monthlyDataCount = site.getComparativeColorMonthly().equalsIgnoreCase("White") ? 1 : 0;
link = "JavaScript:getSiteWiseQuarterlyChapterAnalysis('" + StringEscapeUtils.escapeXml(site.getName())
+ "'," + site.getId() + "," + manager.getValue(AppConstants.QUATERLY) + ",'" + quaterlyFreqName
+ "')";
siteComparativeChart = utility.addHeapMapDataSetNode(site.getName(), quaterlyFreqName,
String.valueOf(roundTwoDecimals(site.getQuarterlyCompliance())), link, siteComparativeChart,
site.getComparativeColorQuarterly());
int quaterlyDataCount = site.getComparativeColorQuarterly().equalsIgnoreCase("White") ? 1 : 0;
link = "JavaScript:getSiteWiseSemiAnnualChapterAnalysis('" + StringEscapeUtils.escapeXml(site.getName())
+ "'," + site.getId() + "," + manager.getValue(AppConstants.SEMI_ANNUAL) + ",'"
+ semiAnnualFreqName + "')";
siteComparativeChart = utility.addHeapMapDataSetNode(site.getName(), semiAnnualFreqName,
String.valueOf(roundTwoDecimals(site.getSemiAnnualCompliance())), link, siteComparativeChart,
site.getComparativeColorSemiAnnual());
int semiAnnualDataCount = site.getComparativeColorSemiAnnual().equalsIgnoreCase("White") ? 1 : 0;
link = "JavaScript:getSiteWiseAnnualChapterAnalysis('" + StringEscapeUtils.escapeXml(site.getName())
+ "'," + site.getId() + "," + manager.getValue(AppConstants.ANNUAL) + ",'" + annualFreqName
+ "')";
siteComparativeChart = utility.addHeapMapDataSetNode(site.getName(), annualFreqName,
String.valueOf(roundTwoDecimals(site.getAnnualCompliance())), link, siteComparativeChart,
site.getComparativeColorAnnual());
int annualDataCount = site.getComparativeColorAnnual().equalsIgnoreCase("White") ? 1 : 0;
naSiteDataCount = monthlyDataCount + quaterlyDataCount + semiAnnualDataCount + annualDataCount;
naSiteDataList.add(naSiteDataCount);
naSiteCounter.add(naSiteDataCount);
site.setNaSiteCount(naSiteDataList);
site.setNaSiteCounter(naSiteCounter);
System.out.println("datacount is" + naSiteDataCount);
}
// Collections.sort(sites, new UniversalComparator("getNaSiteCount", 1));
for (Integer count : site.getNaSiteCount()) {
System.out.println("ALL NA COUNT" + count);
}
for (Integer count1 : site.getNaSiteCounter()) {
System.out.println("ALL NA COUNT" + count1);
}
this.maxSizeSiteName = maxSizeSiteName.replaceAll(" ", ".");
this.maxSizeSiteName = maxSizeSiteName.replaceAll("-", ".");
String xml = utility.getHeapMapXML1(manager.getValue(lang + AppConstants.LABEL_FREQUENCY),
divisionName + "-" + manager.getValue(lang + AppConstants.LABEL_SITES), colList, rowList, "0",
siteComparativeChart);
return xml;
}
return "";
}
当我点击浏览器的后退按钮时，上面的方法被调用，我发现if (divId != null)实际上返回了null，它变成了false，因此变成了return ""
再打一次，它呈现页面，我无法弄清楚到底是什么问题，实际上我在Opera，safari，chrome和mozilla中运行了我的应用程序，没有一个浏览器显示出如此令人恶心的异常
这是浏览器的问题吗 我该如何纠正？ 任何帮助表示赞赏