com.fasterxml.jackson.databind.JsonMappingException through reference chain when there is inconsistency between member type and accessor methods

Question

Is there a configuration to allow Jackson gracefully handle members discrepancy between member variable's type and that used in the getter/setter? For example, if a private variable is declared with type Long and its accessor methods are using type long, we have a problem. Also, we are dealing with code which cannot be changed:

For example, consider this class:

    public class EventArgs {

        private Long id;
        private String message;


        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        public long getId() {
            return id;
        }

        public void setId(long id) {
            this.id = id;
        }

}

Consider the corresponding test:

@Test
    public void shouldSerializeToString() {

        ObjectMapper mapper = new ObjectMapper();
        String value = null;
        try {
            value = mapper.writeValueAsString(new EventArgs());
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }

        Assert.assertNotNull(value);
    }

The test fails with this exception:

com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: com.sailpoint.orchestration.zeebe.model.EventArgs["id"]) at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:394) at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:353) at com.fasterxml.jackson.databind.ser.std.StdSerializer.wrapAndThrow(StdSerializer.java:316) at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:729) at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) 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 com.sailpoint.orchestration.zeebe.workers.EventArgsTests.shouldSerializeToString(EventArgsTests.java:19) 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) Caused by: java.lang.NullPointerException at com.sailpoint.orchestration.zeebe.model.EventArgs.getId(EventArgs.java:18) 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 com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:688) at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:721) ... 28 more

java.lang.AssertionError at org.junit.Assert.fail(Assert.java:86) at org.junit.Assert.assertTrue(Assert.java:41) at org.junit.Assert.assertNotNull(Assert.java:712) at org.junit.Assert.assertNotNull(Assert.java:722) at com.sailpoint.orchestration.zeebe.workers.EventArgsTests.shouldSerializeToString(EventArgsTests.java:24) 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)

Michał Krzywański · Accepted Answer · 2019-10-23 17:23:54Z

2

You could tell Jackson not to use getters and setters and use fields only :

ObjectMapper mapper = new ObjectMapper();
mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE); //turn off everything
mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY); // only use fields

or if you want to disable ONLY getters and setters and use fields (and allow other like JsonCreator) :

mapper.setVisibility(PropertyAccessor.SETTER, JsonAutoDetect.Visibility.NONE);
mapper.setVisibility(PropertyAccessor.GETTER, JsonAutoDetect.Visibility.NONE);
mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

The output JSON is then :

{"id":null,"message":null}

edited Oct 23, 2019 at 17:23

answered Oct 22, 2019 at 20:45

Michał Krzywański

17.1k5 gold badges46 silver badges68 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

com.fasterxml.jackson.databind.JsonMappingException through reference chain when there is inconsistency between member type and accessor methods

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related