JsonMappingException during serialization/deserialization of Integer field

[ErwanLeroux]

Hello, I tried to register Mr Bean Module and i got this exception when I try to deserialize a bean containing an Integer field.

Here is the stacktrace :

com.fasterxml.jackson.databind.JsonMappingException: Can not instantiate value of type [simple type, class org.codehaus.jackson.generated.java.lang.Number] from Integral number; no single-int-arg constructor/factory method
    at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromInt(StdValueInstantiator.java:320)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromNumber(BeanDeserializerBase.java:1106)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:141)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:126)
    at com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer.deserialize(UntypedObjectDeserializer.java:187)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer._readAndBindStringMap(MapDeserializer.java:430)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:312)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:26)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2993)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2105)
    at fr.bov3.jackson.JacksonUtilTest.testIntegerBeanModuleMrBean(JacksonUtilTest.java:169)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Here is a test class i wrote to explicit my problem

package test;

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.module.mrbean.MrBeanModule;

public class MrBeanProblemTest {

    @Test
    public void testIntegerBeanModuleMrBean() throws IOException {

        final class IntegerBean implements Serializable {

            /** serialVersionUID */
            private static final long serialVersionUID = 1L;
            private Integer id;

            public IntegerBean() {
            }

            /**
             * @return the id
             */
            @SuppressWarnings("unused")
            public Integer getId() {
                return id;
            }

            /**
             * @param pId
             *            the id to set
             */
            public void setId(final Integer pId) {
                id = pId;
            }

        }
        // Creation of a simple bean with one Integer Field
        final IntegerBean integerBean = new IntegerBean();
        integerBean.setId(60);

        // Mr Bean registration
        final ObjectMapper mapper = new ObjectMapper();
        mapper.registerModule(new MrBeanModule());

        final String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(integerBean);
        // System.out.println("Json as string : " + json);
        final TypeReference<HashMap<String, Object>> typeMap = new TypeReference<HashMap<String, Object>>() {};

        final Map<String, Object> data = mapper.readValue(json, typeMap);
        assertEquals(60, data.get("id"));
    }
}

This is a simple example, I want to include Mr Bean module in my project which already use Jackson Core and adding Mr Bean breaks it because of this exception.

[cowtowncoder]

Thank you for reporting this. I'll have a look, it should obviously work.

[cowtowncoder]

Hmmh. I am unable to reproduce this with version 2.4.4. The only intentional change is to make sure inner class has static modifier (otherwise things won't work in general), but it passes for me.

So I guess I am wondering if you might be using an old version, and upgrading would help here?

[ErwanLeroux]

Sorry, I forgot to post the dependency I used :

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
  <groupId>com.fasterxml.jackson.module</groupId>
  <artifactId>jackson-module-mrbean</artifactId>
  <version>2.3.1</version>
</dependency>

You were right, upgrading to 2.4.0 solved my problem.

[cowtowncoder]

Ah. I should have checked release notes myself. This was probably a dup of #12, fixed in 2.3.3. :)