当我尝试进行ajax调用时，我遇到了错误。
我正在传递服务调用所需的参数。
我正在收到的错误：
Error |
2015-07-29 19:47:33,493 [http-bio-8080-exec-14] ERROR errors.GrailsExceptionResolver - NullPointerException occurred when processing request: [GET] /forms/landing/deleteSelectedFile - parameters:
attachmentId: 164
Stacktrace follows:
Message: null
Line | Method
->> 48 | execute in org.activiti.engine.impl.cmd.DeleteAttachmentCmd
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| 24 | execute in org.activiti.engine.impl.interceptor.CommandInvoker
| 57 | execute . . . . . . . . . . . . in org.activiti.engine.impl.interceptor.CommandContextInterceptor
| 31 | execute in org.activiti.engine.impl.interceptor.LogInterceptor
| 40 | execute . . . . . . . . . . . . in org.activiti.engine.impl.cfg.CommandExecutorImpl
| 35 | execute in ''
| 357 | deleteAttachment . . . . . . . in org.activiti.engine.impl.TaskServiceImpl
| -1 | invoke in sun.reflect.GeneratedMethodAccessor845
| 43 | invoke . . . . . . . . . . . . in sun.reflect.DelegatingMethodAccessorImpl
| 606 | invoke in java.lang.reflect.Method
| 1270 | jlrMethodInvoke . . . . . . . . in org.springsource.loaded.ri.ReflectiveInterceptor
| 189 | invoke in org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite
| 53 | call . . . . . . . . . . . . . in org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite
| 112 | call in org.codehaus.groovy.runtime.callsite.AbstractCallSite
| 701 | deleteAttachemnt . . . . . . . in grails.power.form.ActivitiService
| -1 | invoke in grails.power.form.ActivitiService$$FastClassBySpringCGLIB$$d4cb6609
| 204 | invoke . . . . . . . . . . . . in org.springframework.cglib.proxy.MethodProxy
| 708 | invokeJoinpoint in org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation
| 157 | proceed . . . . . . . . . . . . in org.springframework.aop.framework.ReflectiveMethodInvocation
| 98 | proceedWithInvocation in org.springframework.transaction.interceptor.TransactionInterceptor$1
| 262 | invokeWithinTransaction . . . . in org.springframework.transaction.interceptor.TransactionAspectSupport
| 95 | invoke in org.springframework.transaction.interceptor.TransactionInterceptor
| 179 | proceed . . . . . . . . . . . . in org.springframework.aop.framework.ReflectiveMethodInvocation
| 644 | intercept in org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor
| -1 | deleteAttachemnt . . . . . . . in grails.power.form.ActivitiService$$EnhancerBySpringCGLIB$$3305bc1c
| 440 | deleteSelectedFile in grails.power.form.LandingController
| -1 | invoke . . . . . . . . . . . . in sun.reflect.GeneratedMethodAccessor784
| 43 | invoke in sun.reflect.DelegatingMethodAccessorImpl
| 606 | invoke . . . . . . . . . . . . in java.lang.reflect.Method
| 1270 | jlrMethodInvoke in org.springsource.loaded.ri.ReflectiveInterceptor
| 154 | invoke . . . . . . . . . . . . in org.codehaus.groovy.grails.web.servlet.mvc.MixedGrailsControllerHelper
| 375 | handleAction in org.codehaus.groovy.grails.web.servlet.mvc.AbstractGrailsControllerHelper
| 252 | executeAction . . . . . . . . . in ''
| 205 | handleURI in ''
| 126 | handleURI . . . . . . . . . . . in ''
| 72 | handleRequest in org.codehaus.groovy.grails.web.servlet.mvc.SimpleGrailsController
| 50 | handle . . . . . . . . . . . . in org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter
| 347 | doDispatch in org.codehaus.groovy.grails.web.servlet.GrailsDispatcherServlet
| 870 | doService . . . . . . . . . . . in org.springframework.web.servlet.DispatcherServlet
| 961 | processRequest in org.springframework.web.servlet.FrameworkServlet
| 852 | doGet . . . . . . . . . . . . . in ''
| 620 | service in javax.servlet.http.HttpServlet
| 837 | service . . . . . . . . . . . . in org.springframework.web.servlet.FrameworkServlet
| 727 | service in javax.servlet.http.HttpServlet
| 303 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 52 | doFilter . . . . . . . . . . . in org.apache.tomcat.websocket.server.WsFilter
| 241 | internalDoFilter in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter . . . . . . . . . . . in ''
| 198 | doFilter in grails.plugin.cache.web.filter.PageFragmentCachingFilter
| 63 | doFilter . . . . . . . . . . . in grails.plugin.cache.web.filter.AbstractFilter
| 344 | invokeDelegate in org.springframework.web.filter.DelegatingFilterProxy
| 261 | doFilter . . . . . . . . . . . in ''
| 241 | internalDoFilter in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter . . . . . . . . . . . in ''
| 101 | doFilter in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 101 | doFilter . . . . . . . . . . . in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter . . . . . . . . . . . in ''
| 101 | doFilter in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 748 | invoke . . . . . . . . . . . . in org.apache.catalina.core.ApplicationDispatcher
| 486 | processRequest in ''
| 411 | doForward . . . . . . . . . . . in ''
| 338 | forward in ''
| 178 | forwardRequestForUrlMappingInfo in org.codehaus.groovy.grails.web.mapping.UrlMappingUtils
| 144 | forwardRequestForUrlMappingInfo in ''
| 135 | forwardRequestForUrlMappingInfo in ''
| 216 | doFilterInternal in org.codehaus.groovy.grails.web.mapping.filter.UrlMappingsFilter
| 107 | doFilter . . . . . . . . . . . in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter . . . . . . . . . . . in ''
| 330 | doFilter in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 181 | doFilter . . . . . . . . . . . in org.springframework.security.web.authentication.switchuser.SwitchUserFilter
| 342 | doFilter in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 118 | invoke . . . . . . . . . . . . in org.springframework.security.web.access.intercept.FilterSecurityInterceptor
| 84 | doFilter in ''
| 342 | doFilter . . . . . . . . . . . in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 113 | doFilter in org.springframework.security.web.access.ExceptionTranslationFilter
| 342 | doFilter . . . . . . . . . . . in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 53 | doFilter in grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter
| 342 | doFilter . . . . . . . . . . . in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 146 | doFilter in org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter
| 342 | doFilter . . . . . . . . . . . in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 154 | doFilter in org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter
| 342 | doFilter . . . . . . . . . . . in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 199 | doFilter in org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter
| 49 | doFilter . . . . . . . . . . . in grails.plugin.springsecurity.web.authentication.RequestHolderAuthenticationFilter
| 342 | doFilter in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 82 | doFilter . . . . . . . . . . . in grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter
| 342 | doFilter in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 87 | doFilter . . . . . . . . . . . in org.springframework.security.web.context.SecurityContextPersistenceFilter
| 342 | doFilter in org.springframework.security.web.FilterChainProxy$VirtualFilterChain
| 192 | doFilterInternal . . . . . . . in org.springframework.security.web.FilterChainProxy
| 160 | doFilter in ''
| 344 | invokeDelegate . . . . . . . . in org.springframework.web.filter.DelegatingFilterProxy
| 261 | doFilter in ''
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 69 | doFilterInternal . . . . . . . in org.codehaus.groovy.grails.web.servlet.mvc.GrailsWebRequestFilter
| 107 | doFilter in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 67 | doFilterInternal . . . . . . . in org.codehaus.groovy.grails.web.filters.HiddenHttpMethodFilter
| 107 | doFilter in org.springframework.web.filter.OncePerRequestFilter
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 88 | doFilterInternal . . . . . . . in org.springframework.web.filter.CharacterEncodingFilter
| 107 | doFilter in org.springframework.web.filter.OncePerRequestFilter
| 344 | invokeDelegate . . . . . . . . in org.springframework.web.filter.DelegatingFilterProxy
| 261 | doFilter in ''
| 241 | internalDoFilter . . . . . . . in org.apache.catalina.core.ApplicationFilterChain
| 208 | doFilter in ''
| 220 | invoke . . . . . . . . . . . . in org.apache.catalina.core.StandardWrapperValve
| 122 | invoke in org.apache.catalina.core.StandardContextValve
| 171 | invoke . . . . . . . . . . . . in org.apache.catalina.core.StandardHostValve
| 103 | invoke in org.apache.catalina.valves.ErrorReportValve
| 116 | invoke . . . . . . . . . . . . in org.apache.catalina.core.StandardEngineValve
| 408 | service in org.apache.catalina.connector.CoyoteAdapter
| 1070 | process . . . . . . . . . . . . in org.apache.coyote.http11.AbstractHttp11Processor
| 611 | process in org.apache.coyote.AbstractProtocol$AbstractConnectionHandler
| 316 | run . . . . . . . . . . . . . . in org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
| 615 | run . . . . . . . . . . . . . . in java.util.concurrent.ThreadPoolExecutor$Worker
| 61 | run in org.apache.tomcat.util.threads.TaskThread$WrappingRunnable
^ 745 | run . . . . . . . . . . . . . . in java.lang.Thread
GSP代码：
<g:each in="${fileList}" var="file">
<div>
<a href="#" onclick="remove('${file.attachmentId}')">
<span class="glyphicon glyphicon-remove"></span></a>
<a href="/forms/landing/attachment/${file.attachmentId}" >${file.name}</a>
</br>
</div>
</g:each>
JAVASCRIPT代码：
function remove(attachmentId) {
$(document).ready(function(){
$('.glyphicon-remove').click ( function(e){
e.preventDefault();
$(this).parent().parent().remove();
$.ajax({
url: "${g.createLink(controller: "landing", action: "deleteSelectedFile")}",
data: {
attachmentId: attachmentId
},
success: function(data){
alert("Success");
}
});
});
});
}
请帮帮我。在此先感谢您的帮助。
答案 0 :(得分：1)
天啊，
服务调用方法的返回类型无效。现在我明确地返回true。
现在正在运作。