Hi, We had also problems and one colleague of mine found out they are all related to
https://bugs.openjdk.org/browse/JDK-8024931 We hunted down all of those. Additionally, we have a "special mode" to run our application where we report all serialization problems into some separated log file and we run our selenium tests against such instances periodically. Thus, we have an early warning system telling us when we reintroduce such problems. Another problem we found with the use of lambdas is that you have to be very careful because you can easily serialize things you don't need to serialize (even if they are serializable) On Tue, Apr 29, 2025 at 1:06 AM Tobias Gierke < tobias.gie...@code-sourcery.de> wrote: > Hi, > > Our company is a long time Wicket user on a large code base (10+ years, > >600k loc) and ever since lambdas got introduced in JDK 8, our Wicket > applications have occasionally been plagued by random crashes during > Wicket Page deserialization like this: > > |Caused by: java.lang.reflect.InvocationTargetException at > java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:109) > > at java.base/java.lang.reflect.Method.invoke(Method.java:580) at > com.vodecc.voipmng.boundary.wicket.WicketApplication$5.lambda$get$0(WicketApplication.java:864) > > ... 63 more Caused by: java.lang.ClassCastException: cannot assign > instance of java.lang.invoke.SerializedLambda to field > <someClass>.<someFieldWithTypeIModel> of type > org.apache.wicket.model.IModel at > java.base/java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2096) > > at > java.base/java.io.ObjectStreamClass$FieldReflector.checkObjectFieldValueTypes(ObjectStreamClass.java:2060) > > at > java.base/java.io.ObjectStreamClass.checkObjFieldValueTypes(ObjectStreamClass.java:1349) > > at > java.base/java.io.ObjectInputStream$FieldValues.defaultCheckFieldValues(ObjectInputStream.java:2697) > > at > java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2498) > > at > java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2284) > > at > java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1762) > > at > java.base/java.io.ObjectInputStream$FieldValues.<init>(ObjectInputStream.java:2618) > > at > java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2469) > > at > java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2284) > > at > java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1762) > > at > java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:540) > > at > java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:498) > > at java.base/java.util.ArrayList.readObject(ArrayList.java:981) at > java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) > > at java.base/java.lang.reflect.Method.invoke(Method.java:580) | > > The offending member field in this particular crash has a type of > 'IModel<String>'. > > With "random crashes" I mean that the same code sometimes works and > sometimes crashes, seemingly dependent on the order in which > (capturing?) lambdas are created or called. > > I did spent some time looking into this and found quite a few > *unresolved* JDK bugs related to ClassCastExceptions during lambda > serialization: > > https://bugs.openjdk.org/browse/JDK-8154236 > https://bugs.openjdk.org/browse/JDK-8208752 > https://bugs.openjdk.org/browse/JDK-8275387 > https://bugs.openjdk.org/browse/JDK-8174864 > https://bugs.openjdk.org/browse/JDK-8174865 > > A comment on JDK-8275387 seemed especially enlightening: "The root cause > is always the same: java.lang.invoke.SerializedLambda can not hold > enough information to correctly identify the which lambda should be > (de-)serialized". This all points to > https://bugs.openjdk.org/browse/JDK-8174864 as the root of the problem. > That ticket mentions that currently, lambda serialization is a lossy > transformation since only the first invocation of any unique > "serialization key" will work (which would explain the randomness we > observed). > > We currently "fix" our crashes by using anonymous classes instead of > lambda expressions but obviously this is not ideal - especially since > (given enough indirections) it's quite hard to find out where the lambda > causing the deserialization crash originated from. > > Cheers, > Tobias > > || > -- Regards - Ernesto Reinaldo Barreiro
