Grails 2.5.5在具有equals方法的域类上使用'as JSON'时出错

Question

I just came into an error when I tried to get the current logged user from springSecurityService and render it as JSON.

def user = springSecurityService.getCurrentUser()
println user as JSON // EXCEPTION!

User is a domain class and had an equals method, the error below happens because the 'as JSON' seems to be calling the equals method (I don't understand why).

User looks like this:

class User implements Serializable {
   ...
   String username
   String password
   String email
   ...

   @Override
   boolean equals(other)
   {
      is(other) || (other.instanceOf(User) && other.username == username)
   }
   ...
}

This is the exception: (the error is on the .instanceOf(User))

2016-10-11 05:40:24,706 [http-bio-8090-exec-1] ERROR errors.GrailsExceptionResolver  - MissingMethodException occurred when processing request: [POST] /ehr/query/save

No signature of method: org.codehaus.groovy.grails.web.json.JSONObject$Null.instanceOf() is applicable for argument types: (java.lang.Class) values: [class com.cabolabs.security.User]. Stacktrace follows:

Message: No signature of method: org.codehaus.groovy.grails.web.json.JSONObject$Null.instanceOf() is applicable for argument types: (java.lang.Class) values: [class com.cabolabs.security.User]

    Line | Method
->>   45 | equals    in com.cabolabs.security.User
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|    176 | value     in grails.converters.JSON
|    134 | render .  in     ''
|    250 | save      in com.cabolabs.ehrserver.query.QueryController
|    198 | doFilter  in grails.plugin.cache.web.filter.PageFragmentCachingFilter
|     63 | doFilter  in grails.plugin.cache.web.filter.AbstractFilter
|     53 | doFilter  in grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter
|     62 | doFilter  in grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter
|   1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    615 | run       in java.util.concurrent.ThreadPoolExecutor$Worker
^    744 | run . . . in java.lang.Thread

Is anyone experimenting the same? Is this the expected behavior or a bug?

Answer 1

Try not to give equals() implementation by yourself, and use this, @EqualsAndHashCode , annotation, provided by Groovy instead. See if that works.

Or

Check the instanceOf() availability before hand, like this

(obj.respondsTo('instanceOf') && obj.instanceOf(User))

using respondsTo() method.