意外标记 (START_OBJECT)，预期 VALUE_STRING：需要 JSON 包含类型 ID 的字符串（对于 java.lang.Object 的子类型）

Question

我已经通过以下几个链接，但它并没有解决我的问题：

Java Jackson: deserialize complex polymorphic object model: JsonMappingException: Unexpected token (START_OBJECT), expected VALUE_STRING
Java Jackson - Unexpected token (START_ARRAY), expected VALUE_STRING

在我的项目中，我们有 15 个批处理作业。我正在将 15 个批处理作业转换为 15 个不同的微服务。为此，我创建了一个 Spring 引导模块，其中包含实体类、JPA 存储库层和服务层。我将把那个 jar 导入到每个微服务（批处理作业）中，这样批处理作业应该可以正常工作。

我正在使用 Spring 引导 + Spring 批处理 - 基于 XML 的方法。

所以我已经准备好 XJPA 模块并将其导入到另一个 Spring 引导模块中，我在其中编写了基于 XML 的批处理作业配置。

代码：

@Component
@EnableBatchProcessing
@ImportResource("classpath:jobs/ABC_context.xml")
public class XXXLauncher {

    @Autowired
    private JobLauncher jobLauncher;

    @Autowired
    private Job job;

    public void executeXXXXXXXXXXJob() {

        try {
            // @formatter:off
            JobParameters jobParameters = new JobParametersBuilder()
                    .addString("runMode", "XXXX")
                    .addDate("date", new Date())
                    .addLong("time", System.currentTimeMillis()).toJobParameters();
            // @formatter:on

            jobLauncher.run(job, jobParameters);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

ABC_job.xml

<batch:job id="x">
    <batch:step id="y">
        <batch:tasklet ref="xyzTasklet" />
    </batch:step>
</batch:job>

<bean id="stepScope" class="org.springframework.batch.core.scope.StepScope">
    <property name="autoProxy" value="true"/>
</bean>

<bean id="xyzTasklet" class="com.XXXX.tasklet.xyzTasklet" scope="step">
    <property name="runType" value="#{jobParameters['runMode']}" />
    <property name="executionContext" value="#{stepExecution.jobExecution.executionContext}" />
</bean>

错误：

Caused by: java.lang.IllegalArgumentException: Unable to deserialize the execution context
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:325) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:309) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:93) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:60) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.doInPreparXXtatement(JdbcTemplate.java:667) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:605) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:657) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:688) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:700) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:756) ~[spring-jdbc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao.getExecutionContext(JdbcExecutionContextDao.java:112) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.batch.core.explore.support.SimpleJobExplorer.getJobExecutionDependencies(SimpleJobExplorer.java:202) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.batch.core.explore.support.SimpleJobExplorer.getJobExecutions(SimpleJobExplorer.java:83) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_162]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_162]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_162]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:197) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at com.sun.proxy.$Proxy83.getJobExecutions(Unknown Source) ~[na:na]
    at org.springframework.batch.core.JobParametersBuilder.getNextJobParameters(JobParametersBuilder.java:264) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.execute(JobLauncherCommandLineRunner.java:162) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.executeLocalJobs(JobLauncherCommandLineRunner.java:179) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.launchJobFromProperties(JobLauncherCommandLineRunner.java:134) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.autoconfigure.batch.JobLauncherCommandLineRunner.run(JobLauncherCommandLineRunner.java:128) ~[spring-boot-autoconfigure-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:800) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    ... 5 common frames omitted
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Unexpected token (START_OBJECT), expected VALUE_STRING: need JSON String that contains type id (for subtype of java.lang.Object)
 at [Source: (ByteArrayInputStream); line: 1, column: 9] (through reference chain: java.util.HashMap["map"])
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:59) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.DeserializationContext.wrongTokenException(DeserializationContext.java:1498) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.DeserializationContext.reportWrongTokenException(DeserializationContext.java:1273) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.jsontype.impl.AsArrayTypeDeserializer._locateTypeId(AsArrayTypeDeserializer.java:151) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.jsontype.impl.AsArrayTypeDeserializer._deserialize(AsArrayTypeDeserializer.java:96) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.jsontype.impl.AsArrayTypeDeserializer.deserializeTypedFromAny(AsArrayTypeDeserializer.java:71) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer$Vanilla.deserializeWithType(UntypedObjectDeserializer.java:712) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer._readAndBindStringKeyMap(MapDeserializer.java:529) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:364) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:29) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013) ~[jackson-databind-2.9.6.jar:2.9.6]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3077) ~[jackson-databind-2.9.6.jar:2.9.6]
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.deserialize(Jackson2ExecutionContextStringSerializer.java:70) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.deserialize(Jackson2ExecutionContextStringSerializer.java:50) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao$ExecutionContextRowMapper.mapRow(JdbcExecutionContextDao.java:322) ~[spring-batch-core-4.0.1.RELEASE.jar:4.0.1.RELEASE]
    ... 34 common frames omitted

另一个错误：现在我得到

Field job in required a bean of type 'org.springframework.batch.core.Job' that could not be found.

Answer 1

一旦我删除了行

objectMapper.enableDefaultTyping();

它解决了我的问题。但要小心，在某些其他情况下，这行是需要的

意外标记 (START_OBJECT)，预期 VALUE_STRING：需要 JSON 包含类型 ID 的字符串（对于 java.lang.Object 的子类型）

Unexpected token (START_OBJECT), expected VALUE_STRING: need JSON String that contains type id (for subtype of java.lang.Object)

spring

spring-batch

spring-data-jpa

jpa-2.1

spring-boot