Yesterday, after a code refactoring, doing a test of the web application I get a mythical StackOverflowError:
java.lang.StackOverflowError at java.util.HashMap.addEntry(HashMap.java:888) at java.util.LinkedHashMap.addEntry(LinkedHashMap.java:427) at java.util.HashMap.put(HashMap.java:509) at java.util.HashSet.add(HashSet.java:217) at org.springframework.core.convert.support.GenericConversionService.addInterfaceHierarchy(GenericConversionService.java:452) at org.springframework.core.convert.support.GenericConversionService.getMatchingConverterForTarget(GenericConversionService.java:437) at org.springframework.core.convert.support.GenericConversionService.findConverterForClassPair(GenericConversionService.java:349) at org.springframework.core.convert.support.GenericConversionService.getConverter(GenericConversionService.java:244) at org.springframework.core.convert.support.GenericConversionService.canConvert(GenericConversionService.java:145) at org.springframework.core.convert.support.IdToEntityConverter.matches(IdToEntityConverter.java:54) ...
strange … on a web form that had not been subject to code changes for a long time.
The project is based on Spring 3.1.0 and Java 7.
By debugging, I find that the failed conversion affects the domain class Address to which the static findAddress method has been added. The signature is as follows:
public static Address findAddress(Address address)
the method has been added to prevent duplicate persistance addresses on the db.
So now the Address class has two static finders:
public static Address findAddress(Address address) public static Address findAddress(Long id)
the IdToEntityConverter class uses the getFinder method whose rules are (from javadoc):
the finder method must be public, static, have the signature find[EntityName]([IdType]), and return an instance of the desired entity type.
The problem is that IdType is converted by searching its finder, which is always of the same type Address, causes the loop resulting in StackOverflowError.
The solution is to rename
findAddress(Address address)
method in
retrieveAddress(Adress address).