Spring Batch No serializer found for class java.io.ByteArrayInputStream for oracle.sql.TIMESTAMP

Question

我使用 Spring Batch 并且有一个作业定义。我可以成功地从 db 中获取数据，但是在尝试处理第一个块后我的工作失败了。

我有一个JdbcPagingItemReader 并且有一个日期字段的排序定义：

    Map<String, Order> sortKeys = new HashMap<>();
    sortKeys.put("MY_DT", Order.ASCENDING);

    OraclePagingQueryProvider queryProvider = new OraclePagingQueryProvider();
    queryProvider.setSelectClause("---");
    queryProvider.setFromClause("FROM ---");
    queryProvider.setWhereClause("WHERE MY_DT >= :myDt");

但是我得到了这个错误：

Caused by: com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class java.io.ByteArrayInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: java.util.HashMap["JdbcPagingItemReader.start.after"]->java.util.LinkedHashMap["MY_DT"]->oracle.sql.TIMESTAMP["stream"])
    at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77)
    at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1277)
    at com.fasterxml.jackson.databind.DatabindContext.reportBadDefinition(DatabindContext.java:400)
    at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:71)
    at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serializeWithType(UnknownSerializer.java:45)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:730)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:755)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeWithType(BeanSerializerBase.java:640)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeTypedFields(MapSerializer.java:941)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:696)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithoutTypeInfo(MapSerializer.java:681)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithType(MapSerializer.java:650)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithType(MapSerializer.java:33)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeTypedFields(MapSerializer.java:941)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:696)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithoutTypeInfo(MapSerializer.java:681)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithType(MapSerializer.java:650)
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithType(MapSerializer.java:33)
    at com.fasterxml.jackson.databind.ser.impl.TypeWrappedSerializer.serialize(TypeWrappedSerializer.java:32)
    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._writeValueAndClose(ObjectMapper.java:4409)
    at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:3621)
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.serialize(Jackson2ExecutionContextStringSerializer.java:141)
    at org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer.serialize(Jackson2ExecutionContextStringSerializer.java:104)
    at org.springframework.batch.core.repository.dao.JdbcExecutionContextDao.serializeContext(JdbcExecutionContextDao.java:302)

我认为这个问题与oracle.sql.TIMESTAMP 没有公共构造函数有关。因此，如果我将排序参数更改为非日期类型，一切都会像魅力一样。但是，即使我尝试自定义对象映射器，我也无法使其与日期排序一起使用。

有什么想法吗？

PS：作为一种解决方法，我尝试了这个但没有用：

@Configuration
public class JacksonObjectMapperConfiguration {

    @Bean
    @Primary
    public ObjectMapper objectMapper() {
        ObjectMapper mapper = new ObjectMapper();
        SimpleModule simpleModule = new SimpleModule();
        simpleModule.addSerializer(TIMESTAMP.class, new OracleTimestampSerializer());
        mapper.registerModule(simpleModule);
        mapper.setVisibility(mapper.getSerializationConfig().getDefaultVisibilityChecker()
                .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
                .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
        return mapper;
    }

    private static class OracleTimestampSerializer extends JsonSerializer<TIMESTAMP> {
        @Override
        public void serializeWithType(oracle.sql.TIMESTAMP timestamp, JsonGenerator gen, SerializerProvider serializers, TypeSerializer typeSerializer) throws IOException {
            WritableTypeId typeId = typeSerializer.writeTypePrefix(gen, typeSerializer.typeId(timestamp, JsonToken.VALUE_EMBEDDED_OBJECT));
            serialize(timestamp, gen, serializers);
            gen.writeTypeSuffix(typeId);
            throw new RuntimeException("Error!");
        }

        @Override
        public void serialize(oracle.sql.TIMESTAMP timestamp, JsonGenerator gen, SerializerProvider serializers) {
            try {
                gen.writeBinary(timestamp.getBytes());
                throw new RuntimeException("Error!");
            } catch (IOException e) {
                System.out.println("serialize oracle.sql.Timestamp error :" + e.getMessage());
            }
        }
    }
}

但是，也不会抛出运行时异常。

Answer 1

从您共享的堆栈跟踪中，我看到问题发生在执行上下文被序列化时。事实上，这是由于默认的 Jackson 映射器不知道如何（反）序列化时间戳。提供自定义映射器是要走的路。但是，为此，您需要在自定义实现中提供自定义 JobRepository 到 JobRepositoryFactoryBean#setSerializer。仅在应用程序上下文中将序列化程序声明为 bean 是不够的（我们计划改进此 here，如果您有兴趣，请对该问题进行投票或评论）。您可以在Configuring a JobRepository 部分找到有关如何自定义作业存储库的更多详细信息。

在您的情况下，您需要提供自定义BatchConfigurer（或扩展DefaultBatchConfigurer）并实现getJobRepository（或覆盖createJobRepository），例如：

@Configuration
@EnableBatchProcessing
public class MyJobConfigWithCustomSerializer {

    @Bean
    public BatchConfigurer batchConfigurer(ObjectMapper objectMapper) {
        return new DefaultBatchConfigurer() {
            @Override
            public JobRepository createJobRepository() throws Exception {
                Jackson2ExecutionContextStringSerializer serializer = new Jackson2ExecutionContextStringSerializer();
                // customize serializer
                serializer.setObjectMapper(objectMapper);
                JobRepositoryFactoryBean factory = new JobRepositoryFactoryBean();
                factory.setSerializer(serializer);
                // set other properties on the factory bean
                factory.afterPropertiesSet();
                return factory.getObject();
            }
        }
    }

}