Fail to serialize `Enum` instance which includes a method override as POJO (shape = Shape.OBJECT)

[ylhuang-veeva]

This problem of failing to serialize an Enum instance which includes a method override only occurs in 2.10.1, not 2.10.0.
Here is a simple test:

public class EnumSerializationTestU {
    @Test
    public void testSerializationOfEnumInstanceWithOverrideMethod() {
        ObjectMapper om = new ObjectMapper();
        om.enable(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS);
        try {
            String stringResult = om.writeValueAsString(EnumWithOverrideMethod.ATTRIBUITES);
            Map result = (Map) om.readValue(stringResult, Map.class);
            assertEquals("attributes", result.get("key"));
        } catch (JsonProcessingException e) {
            System.err.println("Serialization Of EnumInstanceWithOverrideMethod fails: ");
           e.printStackTrace();
        }
    }

    @JsonFormat(shape = JsonFormat.Shape.OBJECT)
    public enum EnumWithOverrideMethod {
        DEFAULT("default"),
        ATTRIBUITES("attributes") {
            public Class sectionInfoClass () {
                return AttributesSectionInfo.class;
            }
        },
        DOC_LAYOUT("doclayout") {
            public Class sectionInfoClass () {
                return DocLayoutSectionInfo.class;
            }
        }
        ;
        private final String key;
        private EnumWithOverrideMethod(String key) {
            this.key = key;
        }
        public String getKey() { return this.key; }

        public Class sectionInfoClass() {
            return null;
        }
    }

    public interface LayoutSectionInfo {
    }

    public class AttributesSectionInfo implements LayoutSectionInfo {
        private LinkedHashMap attributes;
        public LinkedHashMap getAttributes() {
            return attributes;
        }
    }

    public class DocLayoutSectionInfo implements LayoutSectionInfo {
        private String relatedDocField;

        public String getRelatedDocField() {
            return relatedDocField;
        }
        public void setRelatedDocField(String relatedDocField) {
            this.relatedDocField = relatedDocField;
        }
    }
}
**The stack trace for above is:**
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class veeva.ecm.ui.interfaces.web.contract.admin.vobjects.layout.WidgetTypeSerializationTestU$EnumWithOverrideMethod$1 and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)
	at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77)
	at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1191)
	at com.fasterxml.jackson.databind.DatabindContext.reportBadDefinition(DatabindContext.java:404)
	at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:71)
	at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:33)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
	at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:4094)
	at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3404)
	at veeva.ecm.ui.interfaces.web.contract.admin.vobjects.layout.WidgetTypeSerializationTestU.testSerializationOfEnumInstanceWithOverrideMethod(WidgetTypeSerializationTestU.java:31)
	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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

[cowtowncoder]

Thank you for reporting this issue: I was able to reproduce it with a simplified example. Also does not seem to fail for 2.9. I suspect this may be related to type introspection optimizations, wherein some resolution would be avoid for Enum types (I vaguely recall some work that attempted this to improve cold-start performance). This would not affect "regular" Enum handling, even with sub-classing (due to method overload), but in this particular case due to Shape (effectively Enum is treated as POJO) it does.

[cowtowncoder]

Hmmh. Odd. 2.10 fails, 2.11 does not. And master (3.0.0-SNAPSHOT) does. Would have expected all of those to fail.

[cowtowncoder]

Fixed for 2.10. Problem was not quite what I thought, but was able to pinpoint it to specific change in detecting Enum types (JavaType.isEnum() does NOT work for subtypes for 2.10; this was fixed in 2.11, however, which prevented problme there -- but 2.10 breakage was due to refactoring of some kind).

Thank you again for reporting this; fix will be in 2.10.2 which should be released quite soon.