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POPassing a value to a custom tag
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  1. POPassing a value to a custom tag
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    copied!<p>I have a custom tag that I'm trying to pass a String to. It was giving me a NullPointerException. After making some edits suggested below, I am getting ${note} instead of the processed output I had intended. Can anyone help me with this? Here is the relevant code from the JSP. I'm using Struts 2 in my form, and I've marked the line where I'm calling my custom tag.</p> <pre><code>&lt;s:iterator value="bulletins"&gt; &lt;s:if test="approved == false"&gt; &lt;s:form action="ApproveBulletin" method="post"&gt; &lt;table border="2" width="100%"&gt; &lt;tr&gt; &lt;td colspan="2"&gt;&lt;b&gt;From:&lt;/b&gt; &lt;s:property value="name" /&gt;&lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td colspan="2"&gt;&lt;b&gt;Subject:&lt;/b&gt; &lt;s:property value="subject" /&gt;&lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td colspan="2"&gt;&lt;b&gt;Date:&lt;/b&gt; &lt;s:property value="date" /&gt; &lt;br&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;!-- Custom tag is here -- my variable is note --&gt; &lt;td colspan="2"&gt;&lt;t:notePrint note="%{note}" /&gt; &lt;s:hidden name="id" value="%{id}" /&gt;&lt;/td&gt;&lt;s:hidden name="id" value="%{id}" /&gt;&lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt;&lt;s:submit type="button" name="approve" value="Approve" /&gt;&lt;/td&gt; &lt;td&gt;&lt;s:submit type="button" name="deny" value="Deny" /&gt;&lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;br /&gt; &lt;/s:form&gt; &lt;/s:if&gt; &lt;/s:iterator&gt; </code></pre> <p>Here is my tld.</p> <pre><code>&lt;?xml version="1.0" encoding="ISO-8859-1" ?&gt; &lt;!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/j2ee/dtd/web-jsptaglibrary_1_2.dtd"&gt; &lt;taglib&gt; &lt;tlib-version&gt;1.0&lt;/tlib-version&gt; &lt;jsp-version&gt;1.1&lt;/jsp-version&gt; &lt;short-name&gt;NotePrintTag&lt;/short-name&gt; &lt;uri&gt;notePrintTag&lt;/uri&gt; &lt;tag&gt; &lt;name&gt;notePrint&lt;/name&gt; &lt;tag-class&gt;tags.NotePrint&lt;/tag-class&gt; &lt;body-content&gt;scriptless&lt;/body-content&gt; &lt;attribute&gt; &lt;name&gt;note&lt;/name&gt; &lt;/attribute&gt; &lt;/tag&gt; &lt;/taglib&gt; </code></pre> <p>Here is my tag. The NullPointerException actually shows up here, and I've marked the line.</p> <pre><code>public class NotePrint extends SimpleTagSupport { private String note; public void setNote(String note) { this.note = note; } public String getNote() { return note; } public void doTag() throws JspException, IOException { PageContext pageContext = (PageContext) getJspContext(); JspWriter out = pageContext.getOut(); ActionContext.getContext().getValueStack().findValue(note); String[] noteArray = note.split("\n"); for (int i = 0; i &lt; noteArray.length; i++) { out.println(noteArray[i] + "&lt;br /&gt;&lt;br /&gt;"); } } } </code></pre> <p>Here is my exception report.</p> <pre><code>java.lang.NullPointerException tags.NotePrint.doTag(NotePrint.java:24) org.apache.jsp.BulletinApproval_jsp._jspx_meth_t_005fnotePrint_005f0(BulletinApproval_jsp.java:396) org.apache.jsp.BulletinApproval_jsp._jspx_meth_s_005fform_005f0(BulletinApproval_jsp.java:293) org.apache.jsp.BulletinApproval_jsp._jspx_meth_s_005fif_005f0(BulletinApproval_jsp.java:229) org.apache.jsp.BulletinApproval_jsp._jspx_meth_s_005fiterator_005f0(BulletinApproval_jsp.java:189) org.apache.jsp.BulletinApproval_jsp._jspService(BulletinApproval_jsp.java:109) org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:159) 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:251) 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.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243) 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.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:164) 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) com.opensymphony.xwork2.ActionChainResult.execute(ActionChainResult.java:222) 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:251) 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.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243) 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.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:164) 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:485) org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395) </code></pre>
 

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