如何捕获从Jasper报表图像servlet引发的异常

Question

我的web应用程序使用JASPERREPORTS来编译和提供各种报告。报告中显示的所有图像都来自ImageServlet网络。旧金山。jasperreports。j2ee。servlets。ImageServlet。

<servlet>
    <servlet-name>ImageServlet</servlet-name>
    <servlet-class>net.sf.jasperreports.j2ee.servlets.ImageServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>ImageServlet</servlet-name>
    <url-pattern>/image</url-pattern>
</servlet-mapping>

对图像的请求如下所示：

GET /watapp/image?rand=0.5039537955900038&image=px

在我的应用程序的安全审计中，有人提出，如果更改查询参数，如设置image=pxxx，会导致500内部服务器错误。所以我需要处理这个异常。

net.sf.jasperreports.engine.JRRuntimeException: Invalid image name: pxxx
        at net.sf.jasperreports.engine.export.JRHtmlExporter.getPrintElementIndex(JRHtmlExporter.java:2408)
        at net.sf.jasperreports.engine.export.JRHtmlExporter.getImage(JRHtmlExporter.java:695)
        at net.sf.jasperreports.j2ee.servlets.ImageServlet.service(ImageServlet.java:98)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at com.watapp.filters.login.ApplicationFilter.doFilter(ApplicationFilter.java:41)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        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:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        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:298)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
        at java.lang.Thread.run(Thread.java:662)

我的问题是，如何处理这个异常？servlet与JASPER jar一起出现，我无法控制servlet的代码。请建议。

Answer 1

创建您自己的servlet，并修改图像的servlet映射，以指向该映射，而不是jasper servlet。

您的新servlet不必做任何工作，它可以简单地将请求传递给jasper servlet，但它使您能够插入异常处理程序来捕获JRRuntimeException。