[TAP5-2674] Type coercer contribution - cast exception in equals

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 5.7.0, 5.7.1, 5.7.2
• Fix Version/s: 5.7.3
• Component/s: tapestry-core
• Assignee: Ben Weidig
• Reporter: Cédric BOONE
• Created: 21/Apr/21 16:07
• Updated: 27/Apr/21 17:46
• Resolved: 27/Apr/21 17:46

Description

I have multiple Tapestry modules which contribute to type coercer, I can't make it work.

 

I contribute TypeCoercer this way

 

public static void contributeTypeCoercer(MappedConfiguration<CoercionTuple.Key, CoercionTuple> configuration) {

      Coercion<String, Class> coercion = path -> {
         try {
            return Class.forName(path);
         } catch (ClassNotFoundException e) {
            return null;
         }

      };

      CoercionTuple<String, Class> tuple = new CoercionTuple<>(String.class, Class.class, coercion);

      configuration.override(tuple.getKey(), tuple);
   }

 

When I try to access a Tapestry page I get the following:

 

 

Caused by: java.lang.ClassCastException: org.apache.tapestry5.commons.services.CoercionTuple$Key cannot be cast to org.apache.tapestry5.commons.services.CoercionTuple
	at org.apache.tapestry5.commons.services.CoercionTuple$Key.equals(CoercionTuple.java:184)
	at java.util.HashMap.getNode(HashMap.java:572)
	at java.util.HashMap.get(HashMap.java:557)
	at org.apache.tapestry5.ioc.internal.ValidatingMappedConfigurationWrapper.override(ValidatingMappedConfigurationWrapper.java:122)
	at **********.SessionsSubModule.contributeTypeCoercer(SessionsSubModule.java:63)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.tapestry5.ioc.internal.ContributionDefImpl.invokeMethod(ContributionDefImpl.java:133)
	... 219 more

 

The exception is raised in the equals method of CoercionTuple.Key:

@Override
        public boolean equals(Object obj) 
        {
            if (this == obj)
                return true;
            if (obj == null)
                return false;
            if (getClass() != obj.getClass())
                return false;
            // Exception is raised here
            CoercionTuple other = (CoercionTuple) obj;
            if (sourceType == null) 
            {
                if (other.sourceType != null)
                    return false;
            } else if (!sourceType.equals(other.sourceType))
                return false;
            if (targetType == null) 
            {
                if (other.targetType != null)
                    return false;
            } else if (!targetType.equals(other.targetType))
                return false;
            return true;
        }

The equals is called in the HashMap#get implementation (used in ValidatingMappedConfigurationWrapper)

 

With this part of code:

...
if (getClass() != obj.getClass()) 
     return false;

CoercionTuple other = (CoercionTuple) obj;
...

the obj variable can't be a CoercionTuple, it will be a CoercionTuple.Key (which is the case in the implementation of HashMap<CoercionTupe.Key, CoercionTuple>#get).

I might not have understood something, if it is the case, I'm sorry for the trouble.