Spring Batch 4.2.4: Unable to deserialize the execution context

Question

I was using spring-batch:4.2.2.RELEASE as part of spring-boot-starter-batch:2.2.4.RELEASE. After upgrading the latter to version 2.3.1.RELEASE, I get the following exception when starting a job:

java.lang.IllegalArgumentException: Unable to deserialize the execution context
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:328)
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:312)
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:94)
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:61)
    at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:679)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:617)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:669)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:700)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:712)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:768)
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao.getExecutionContext(JdbcExecutionContextDao.java:129)
    at org.springframework.batch.core.explore.support.SimpleJobExplorer.getStepExecutionDependencies(SimpleJobExplorer.java:238)
    at org.springframework.batch.core.explore.support.SimpleJobExplorer.getJobExecutions(SimpleJobExplorer.java:87)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
    at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
    at com.sun.proxy.$Proxy145.getJobExecutions(Unknown Source)
...
Caused by: com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [map type; class java.util.HashMap, [simple type, class java.lang.String] -> [simple type, class java.lang.Object]]: missing type id property '@class'
 at [Source: (ByteArrayInputStream); line: 1, column: 192]
    at com.fasterxml.jackson.databind.exc.InvalidTypeIdException.from(InvalidTypeIdException.java:43)
    at com.fasterxml.jackson.databind.DeserializationContext.missingTypeIdException(DeserializationContext.java:1790)
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingTypeId(DeserializationContext.java:1319)
    at com.fasterxml.jackson.databind.jsontype.impl.TypeDeserializerBase._handleMissingTypeId(TypeDeserializerBase.java:303)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedUsingDefaultImpl(AsPropertyTypeDeserializer.java:166)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:107)
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserializeWithType(MapDeserializer.java:400)
    at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:68)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4482)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3479)
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.deserialize(Jackson2ExecutionContextStringSerializer.java:123)
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.deserialize(Jackson2ExecutionContextStringSerializer.java:102)
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:325)
    ... 45 common frames omitted

I understand that the new version has a restricted handling of JSON deserialization and attempted to implement the suggested fix from the Jackson2ExecutionContextStringSerializer javadoc, however the problem persists:

@EnableBatchProcessing
@Configuration
class BatchConfig(

    val properties: BatchProperties,
    val dataSource: DataSource,
    val transactionManagerCustomizers: TransactionManagerCustomizers,
    val entityManagerFactory: EntityManagerFactory
) : JpaBatchConfigurer(properties, dataSource, transactionManagerCustomizers, entityManagerFactory) {

    override fun createJobRepository(): JobRepository {
        val factory = JobRepositoryFactoryBean()
        val map = PropertyMapper.get()
        map.from(dataSource).to { dataSource: DataSource? -> factory.setDataSource(dataSource!!) }
        map.from { determineIsolationLevel() }.whenNonNull().to { isolationLevelForCreate: String? -> factory.setIsolationLevelForCreate(isolationLevelForCreate!!) }
        map.from { properties.tablePrefix }.whenHasText().to { tablePrefix: String? -> factory.setTablePrefix(tablePrefix!!) }
        map.from { transactionManager }.to { transactionManager: PlatformTransactionManager? -> factory.transactionManager = transactionManager!! }
        factory.afterPropertiesSet()

        val serializer = configureContextSerializer()
        factory.setSerializer(serializer)

        return factory.getObject()
    }

    private fun configureContextSerializer(): Jackson2ExecutionContextStringSerializer {
        val polymorphicTypeValidator = LaissezFaireSubTypeValidator()
        objectMapper.activateDefaultTyping(polymorphicTypeValidator)
        val serializer = Jackson2ExecutionContextStringSerializer()
        serializer.setObjectMapper(objectMapper)
        return serializer
    }

The craziest part is that the execution context is actually empty, the database value is always "{}". I even tried changing all values in the DB to "{"@class":"java.util.HashMap"}", but I still get the same exception.

Does anyone have an idea how to fix this? Is the configuration from my fix attempt wrong?

Answer 1

Thanks to @MahmoudBenHassine for pointing me in the direction of the fix:

My attempt to manually add the type information to the database values was correct, but I didn't take it far enough.

There are 2 tables, whose values that needed updating:

• table batch_job_execution_context, column short_context
• table batch_step_execution_context, column short_context

I did this with a liquibase script:

    <changeSet id="update-job_execution_context-for-spring-batch-4.2.4" author="kpentchev">
        <update tableName="batch_step_execution_context">
            <column name="short_context" valueComputed="REPLACE(short_context, '{', '{&quot;@class&quot;:&quot;java.util.HashMap&quot;,')" />
        </update>
    </changeSet>

    <changeSet id="update-step_execution_context-for-spring-batch-4.2.4" author="kpentchev">
        <update tableName="batch_step_execution_context">
            <column name="short_context" valueComputed="REPLACE(short_context, '{', '{&quot;@class&quot;:&quot;java.util.HashMap&quot;,')" />
        </update>
    </changeSet>

The configuration overriding was not needed.

It would have been nice to have a migration service as part of the spring-batch release, but here is a work-around.