Infinite Stack Trace Loop for Invocation Exception with Abstract Mapper

[IDoCodingStuffs]

java.lang.RuntimeException: java.lang.reflect.InvocationTargetException at jdk.internal.reflect.GeneratedConstructorAccessor4.newInstance(Unknown Source) at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488) at org.mapstruct.factory.Mappers.doGetMapper(Mappers.java:85) at org.mapstruct.factory.Mappers.getMapper(Mappers.java:69) at org.mapstruct.factory.Mappers.getMapper(Mappers.java:58) at com.____.OutboundRequestMapper.<init>(OutboundRequestMapper.java:19) at com.______.OutboundRequestMapperImpl.<init>(OutboundRequestMapperImpl.java:28) at jdk.internal.reflect.GeneratedConstructorAccessor4.newInstance(Unknown Source) at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488) at org.mapstruct.factory.Mappers.doGetMapper(Mappers.java:85) at org.mapstruct.factory.Mappers.getMapper(Mappers.java:69) at org.mapstruct.factory.Mappers.getMapper(Mappers.java:58) ... Same lines just keep repeating until memory is full ...

The line 19 for the OutboundRequestMapper is this:

OutboundRequestMapper INSTANCE = Mappers.getMapper(OutboundRequestMapper.class);
The line mentioned for the Impl class is just the class declaration itself. The rest are all from default libraries.

[IDoCodingStuffs]

Removing the self referring INSTANCE takes care of the problem. So either those should not be allowed inside abstract mappers or whatever is causing the invocation exception should be fixed.

[sjaakd]

So.. without any code your issue is a bit hard to grasp.. Can you add some reproducer?

[IDoCodingStuffs]

@Mapper
public abstract class OutBoundRequestMapper implements .../*interfaces with some mappings*/... {
  OutboundRequestMapper INSTANCE = Mappers.getMapper(OutboundRequestMapper.class);

  public abstract Object map(Object source);
}

Run mvn clean install to reproduce

[sjaakd]

OutboundRequestMapper INSTANCE = Mappers.getMapper(OutboundRequestMapper.class) should be used when you don't have a DI framework like Spring or CDI (referred to in the documentation as the default component model). Although the documentation is perhaps not too clear, the examples are.

Let me know if the documentation is clear. If not, let us know of alternatively file a PR to enhance it..

I'm going to close this issue as it is documented.

[chris922]

OutboundRequestMapper INSTANCE = Mappers.getMapper(OutboundRequestMapper.class) should be used when you don't have a DI framework like Spring or CDI

You mean public static OutboundRequestMapper INSTANCE = Mappers.getMapper(OutboundRequestMapper.class) ?

In an (abstract) class the variable must be declared as static, otherwise it will be evaluated everytime the class will be instantiated.