Hi,
I m trying to write a custom component in Java template. I've gone through
the documentation and the java template plugin source code and able to write
a simple component (in fact I've copied one of the tag and changed the name
nad trying to use it)
*DataGridHandler.java*
public class DataGridHandler extends AbstractTagHandler implements
> TagGenerator {
> @Override
> public void generate() throws IOException {
> Map<String, Object> params = context.getParameters();
> Attributes attr = new Attributes();
>
> attr.addIfExists("name", params.get("name"))
> .addIfExists("id", params.get("id"))
> .addIfExists("class", params.get("cssClass"))
> .addIfExists("style", params.get("cssStyle"))
> .addIfExists("title", params.get("title"));
>
> super.start("div", attr);
> }
>
> public static class CloseHandler extends AbstractTagHandler implements
> TagGenerator {
> public void generate() throws IOException {
> end("div");
> }
> }
>
> }
>
But When I try to run, I m getting below exception.
java.lang.NullPointerException
>
> org.apache.struts2.components.template.TemplateEngineManager.getTemplateEngine(TemplateEngineManager.java:102)
> org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:549)
> org.apache.struts2.components.UIBean.end(UIBean.java:513)
>
> org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
>
> org.apache.jsp.WEB_002dINF.content.test_jsp._jspx_meth_s_005fcomponent_005f0(test_jsp.java:92)
>
> org.apache.jsp.WEB_002dINF.content.test_jsp._jspService(test_jsp.java:61)
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
>
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
>
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
> org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
>
> 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.FilterDispatcher.doFilter(FilterDispatcher.java:395)
>
Can someone please tell me the mistake I m doing or can point out some
resource on writing custom java template components?
Thanks,
Regards,
ManiKanta G
twitter.com/manikantag
