Grails validate runtime error - validation

Question

I use grails validate() function in my very simple update action inside a controller. The problem is very starnge. validate() is not executed at all and giving no error and stopping the execution. I am using Grails 2.3.3
Only the log gives the following error:
Runtime error executing action
Here is my controller code:
def update() {
println(params);
def study = Study.findByUid(params.uid);
study.description = params.description;
println(study); //study is found and printed
study.validate();
println("here"); //not executed and code below is also not executed
if(study.hasErrors()){
study.errors.each{
println it
}
render 'not saved!'
}
if (!study.save()) {
println("Error");
withFormat renderInternalError
}
else {
render "OK"
}
}
Stacktrace:
Request received for '/study/update':
org.apache.catalina.connector.RequestFacade#1eaba95c
servletPath:/study/update
pathInfo:null
Security filter chain: [
SecurityContextPersistenceFilter
MutableLogoutFilter
RequestHolderAuthenticationFilter
SecurityContextHolderAwareRequestFilter
GrailsRememberMeAuthenticationFilter
GrailsAnonymousAuthenticationFilter
ExceptionTranslationFilter
FilterSecurityInterceptor
]
************************************************************
2013-11-27 11:56:04,738 [http-bio-8080-exec-9] DEBUG filter.GrailsRememberMeAuthenticationFilter - SecurityContextHolder not populated with remember-me token, as it already contained: 'org.springframework.security.authentication.UsernamePasswordAuthenticationToken#f6816ea3: Principal: grails.plugin.springsecurity.userdetails.GrailsUser#b29dace9: Username: creator#example.com; Password: [PROTECTED]; Enabled: true; AccountNonExpired: true; credentialsNonExpired: true; AccountNonLocked: true; Granted Authorities: ROLE_USER; Credentials: [PROTECTED]; Authenticated: true; Details: org.springframework.security.web.authentication.WebAuthenticationDetails#1c07a: RemoteIpAddress: 127.0.0.1; SessionId: A1813ED8541AAC773CEF349475DB24A2; Granted Authorities: ROLE_USER'
2013-11-27 11:56:04,738 [http-bio-8080-exec-9] DEBUG filter.GrailsAnonymousAuthenticationFilter - SecurityContextHolder not populated with anonymous token, as it already contained: '{0}'
2013-11-27 11:56:04,740 [http-bio-8080-exec-9] TRACE intercept.AnnotationFilterInvocationDefinition - new candidate for '{0}': '{1}':{2}
2013-11-27 11:56:04,740 [http-bio-8080-exec-9] TRACE intercept.AnnotationFilterInvocationDefinition - config for '{0}' is '{1}':{2}
2013-11-27 11:56:04,741 [http-bio-8080-exec-9] TRACE core.StandardWrapper - Returning non-STM instance
2013-11-27 11:56:04,743 [http-bio-8080-exec-9] DEBUG simple.MemoryPageFragmentCachingFilter - No cacheable annotation found for POST:/hdspro/grails/study/update.dispatch [controller=study, action=update]
2013-11-27 11:56:05,651 [http-bio-8080-exec-9] DEBUG errors.GrailsExceptionResolver - Resolving exception from handler [org.codehaus.groovy.grails.web.servlet.mvc.SimpleGrailsController#98f1784]: org.codehaus.groovy.grails.web.servlet.mvc.exceptions.ControllerExecutionException: Executing action [update] of controller [com.digithurst.hdspro.StudyController] caused exception: Runtime error executing action
2013-11-27 11:56:05,651 [http-bio-8080-exec-9] DEBUG errors.GrailsExceptionResolver - Resolving to view '/error' for exception of type [org.codehaus.groovy.grails.web.servlet.mvc.exceptions.ControllerExecutionException], based on exception mapping [java.lang.Exception]
2013-11-27 11:56:05,651 [http-bio-8080-exec-9] DEBUG errors.GrailsExceptionResolver - Exposing Exception as model attribute 'exception'
2013-11-27 11:56:05,951 [http-bio-8080-exec-9] ERROR errors.GrailsExceptionResolver - StackOverflowError occurred when processing request: [POST] /hdspro/study/update - parameters:
acessionNumber: 3
uid: 3
description: Elbogen123
Stacktrace follows:
org.codehaus.groovy.grails.web.servlet.mvc.exceptions.ControllerExecutionException: Executing action [update] of controller [com.digithurst.hdspro.StudyController] caused exception: Runtime error executing action
at grails.plugin.cache.web.filter.PageFragmentCachingFilter.doFilter(PageFragmentCachingFilter.java:200)
at grails.plugin.cache.web.filter.AbstractFilter.doFilter(AbstractFilter.java:63)
at grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter.doFilter(GrailsAnonymousAuthenticationFilter.java:53)
at grails.plugin.springsecurity.web.authentication.RequestHolderAuthenticationFilter.doFilter(RequestHolderAuthenticationFilter.java:49)
at grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter.doFilter(MutableLogoutFilter.java:82)
at grails.plugin.springsecurity.web.filter.DebugFilter.invokeWithWrappedRequest(DebugFilter.java:102)
at grails.plugin.springsecurity.web.filter.DebugFilter.doFilter(DebugFilter.java:69)
......
/
Study class:
class Study extends Document {
String uid
String description
String accessionNumber
Date date
String toString(){
return "Study" + uid + ": " + description;
}
}

Answer 1

From the comments I've read, you say you did not add any constraints to the domain class. From what I know validate() uses these constraints to check if your instance has errors. Ex:
class CartType {
String name
static constraints = {
name blank: false, nullable:false, maxSize: 50
}
String toString(){name}
}
In this example class we have a cartType. When we call validate() grails will check the constraint block. In this case it will check that the name is not left blank in the form, it cannot be null and that it's max size is 50 characters.
Note: The constraints block can also help grails build the database.
If you did not declare any contraints validate() will not have anything to check against. You will also most likely get an error when a value is null, because, by default, nullable is set to false.