5
मैं अपने सिर पर बैंग कर रहा हूं कि मेरा कस्टम टैगलिब फ़ंक्शन क्यों काम नहीं कर रहा है। उदाहरण Math.cos और Math.sin का उपयोग कर रहा है।बहुत ही सरल कस्टम टैगलिब फ़ंक्शन काम नहीं कर रहा है
package foo.tags;
public class Math {
public java.lang.Double cos(java.lang.Double value) {
return java.lang.Math.cos(value);
}
public java.lang.Double sin(java.lang.Double value) {
return java.lang.Math.sin(value);
}
}
यहाँ .TLD फ़ाइल है:
यहाँ वर्ग है
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version="2.0">
<tlib-version>2.0</tlib-version>
<uri>/WEB-INF/tags/math.tld</uri>
<function>
<name>cos</name>
<function-class>foo.tags.Math</function-class>
<function-signature>java.lang.Double cos(java.lang.Double)</function-signature>
</function>
<function>
<name>sin</name>
<function-class>foo.tags.Math</function-class>
<function-signature>java.lang.Double sin(java.lang.Double)</function-signature>
</function>
</taglib>
बुला कोड के इम्पोर्टेन्ट स्निपेट:
<%@ taglib prefix="math" uri="/WEB-INF/tags/math.tld" %>
<span>${math:sin(180)}</span>
मैं पर एक नल पॉइंटर एक्सेप्शन हो रही है math:sin(180) के साथ लाइन। क्या कोई देखता है कि मैं क्या गलत कर रहा हूं? अगर मुझे अधिक जानकारी की आवश्यकता है तो मुझे बताएं लेकिन अपवाद स्वयं बहुत ही जानकारीपूर्ण नहीं है। धन्यवाद!
Mar 17, 2013 2:27:14 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Foo] in context with path [/Foo] threw exception [org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/jsp/svg/clock1.jsp at line 10
[OTHER LINES REDACTED]
10: <span>${math:sin(180)}</span>
[OTHER LINES REDACTED]
Stacktrace:] with root cause
java.lang.NullPointerException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.el.parser.AstFunction.getValue(AstFunction.java:112)
at org.apache.el.parser.AstMult.getValue(AstMult.java:39)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:985)
at org.apache.jsp.<REDACTED>
at org.apache.jsp.<REDACTED>
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:954)
at org.apache.jsp.<REDACTED>
at org.apache.jsp.<REDACTED>
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1047)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:817)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at Foo.page.filter.SimulationProgressFilter.doFilter(SimulationProgressFilter.java:88)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at fOO.page.filter.CurrentSessionStateFilter.doFilter(CurrentSessionStateFilter.java:119)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
वैसे भी अपवाद दें। – BevynQ
ठीक है, मैंने स्टैकट्रैक जोड़ा लेकिन मुझे अपने वास्तविक वर्ग पथों को फू के साथ प्रतिस्थापित करना पड़ा और मैंने अपवाद (माफ करना, स्वामित्व और ऐसे) में जेएसपी की गैर-अपमानजनक रेखाओं को दोबारा शुरू किया। मुझे उम्मीद है यह मदद करेगा। –