XmlMapper maps null value of xml element with atribute

[stefanCotruta]

Search before asking

• I searched in the issues and found nothing similar.

Describe the bug

Jackson 2.17.2 correctly maps the xml element containing an attribute to a Java record. If I use 2.18.3 (was: 2.18.2), it only recognizes the attribute but not the value.

Version Information

2.18.2 (tested with 2.18.3 too)

Reproduction

public class DemoApplication {

    public static void main(String[] args) {
        String xml = "<Amt Ccy=\"EUR\">1</Amt>";

        XmlMapper mapper = new XmlMapper();
        Assertions.assertDoesNotThrow(() -> mapper.readValue(xml, Amount.class));        
    }

    private record Amount(@JacksonXmlProperty String value, @JacksonXmlProperty(isAttribute = true, localName = "Ccy") String currency) {}
}

// Using 2.17.2 for both dependencies instead of 2.18.2 works correctly without any code changes
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.18.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
            <version>2.18.2</version>
        </dependency>

Output

Exception in thread "main" org.opentest4j.AssertionFailedError: Unexpected exception thrown: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "" (class com.example.demo.DemoApplication$Amount), not marked as ignorable (2 known properties: "value", "Ccy"])
 at [Source: (StringReader); line: 1, column: 23] (through reference chain: com.example.demo.DemoApplication$Amount[""])
	at org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:152)
	at org.junit.jupiter.api.AssertDoesNotThrow.createAssertionFailedError(AssertDoesNotThrow.java:84)
	at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:75)
	at org.junit.jupiter.api.AssertDoesNotThrow.assertDoesNotThrow(AssertDoesNotThrow.java:58)
	at org.junit.jupiter.api.Assertions.assertDoesNotThrow(Assertions.java:3228)
	at com.example.demo.DemoApplication.main(DemoApplication.java:13)
Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "" (class com.example.demo.DemoApplication$Amount), not marked as ignorable (2 known properties: "value", "Ccy"])
 at [Source: (StringReader); line: 1, column: 23] (through reference chain: com.example.demo.DemoApplication$Amount[""])
	at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:61)
	at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:1153)
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:2245)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1821)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperties(BeanDeserializerBase.java:1771)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:561)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1497)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:348)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:185)
	at com.fasterxml.jackson.dataformat.xml.deser.XmlDeserializationContext.readRootValue(XmlDeserializationContext.java:104)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4931)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3868)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3836)
	at com.example.demo.DemoApplication.lambda$main$0(DemoApplication.java:13)

Additional context

Same issue with 2.18.3

[pjfanning]

Please do not provide screen shots. Provide text. Please also provide the Amount class definition so the issue can be reproduced.

[cowtowncoder]

+1 to what @pjfanning said.

[stefanCotruta]

Please do not provide screen shots. Provide text. Please also provide the Amount class definition so the issue can be reproduced.

I updated the post, hope this helps.

[cowtowncoder]

Thanks. 2 more things:

1. Should not depend on Spring Boot -- but I think parts can be just dropped.
2. Instead of System.out.println(amount); would it be possible to either use assertions, or include observed output here?

Also: I assume 2.18.3 is same as 2.18.2 (was recently released, no XML-specific changes).

[stefanCotruta]

I updated it. The issue is on 2.18.3 as well.

[pjfanning]

I tested this on master (Jackson 3) and that record definition serializes with

<Amount Ccy="EUR"><value>1</value></Amount>

I haven't had a chance to test with Jackson 2.17 but the XML above is actually what I would expect based on the record definition and annotations.

[pjfanning]

@stefanCotruta are you sure that this is not the record deinition that you want.

record Amount(@JacksonXmlText String value,
                  @JacksonXmlProperty(isAttribute = true, localName = "Ccy") String currency) {}

@JacksonXmlText flattens the value so that it is expected to appear in the wrapping element as opposed to having its own value element.

With this record definition, I seem to be reproducing your issue.

[stefanCotruta]

I replaced the record with a class and used "@JacksonXmlText" for the value and it works.

    public static class Amount {
        @JacksonXmlText
        private String value;

        @JacksonXmlProperty(isAttribute = true, localName = "Ccy")
        private String currency;

        public Amount() {}

        @Override
        public String toString() {
            return "Amount{" +
                    "value='" + value + '\'' +
                    ", currency='" + currency + '\'' +
                    '}';
        }
    }

I couldn't get it to work using records even if I used the record you suggested (with "@JacksonXmlText").

The exception becomes:

Exception in thread "main" com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Invalid definition for property '' (of type `com.example.demo.DemoApplication$Amount`): Could not find creator property with name '' (known Creator properties: [value, Ccy])
 at [Source: (StringReader); line: 1, column: 1]
	at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:62)
	at com.fasterxml.jackson.databind.DeserializationContext.reportBadPropertyDefinition(DeserializationContext.java:1883)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.addBeanProps(BeanDeserializerFactory.java:636)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer(BeanDeserializerFactory.java:277)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:151)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:471)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:415)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:317)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:284)
	at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:174)
	at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:669)
	at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:5048)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4918)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3860)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3828)
	at com.example.demo.DemoApplication.main(DemoApplication.java:14)

[pjfanning]

@stefanCotruta so you can workaround this issue with the class definition instead of a a record? We can still leave this open to investigate the record issue.

[stefanCotruta]

i would like to avoid doing that. Is there another way to get the expected behaviour using 2.18.2/3? I couldn't find any documentation highlighting changes for record mapping.