使用 Spring Data Redis 序列化时如何正确忽略类成员？答案

【问题标题】：How to correctly ignore class members when serializing w/ Spring Data Redis?使用 Spring Data Redis 序列化时如何正确忽略类成员？
【发布时间】：2018-09-06 10:15:06
【问题描述】：

我希望有人可以提供帮助，因为我真的不知道如何解决以下问题：我想用 Spring Data Redisin 分别序列化 Entity 和 ThumbnailUrlEntity 的一些对象（见下面的代码）@ 987654324@。由于这些类有我不想序列化的成员，因此我尝试以各种方式忽略它们，方法是使用 @JsonIgnoreProperties 注释类本身或使用 @JsonIgnore 或 Filters 注释相应的成员/属性RedisConfig.javaCustomConversion。

现在的问题是，无论我尝试哪种忽略方式，当我尝试保存相应的对象时，我总是得到相同的错误org.springframework.data.keyvalue.core.UncategorizedKeyValueException: Path to property must not be null or empty.; nested exception is java.lang.IllegalArgumentException: Path to property must not be null or empty.。（有关详细信息，请参阅下面的 Stacktrace）

我什至用 MixIn 尝试过这些课程，但效果不佳...

那么问题来了：使用 Spring-Data-Redis 序列化某个类的对象时如何正确忽略属性？

Entity.java

@EqualsAndHashCode(exclude = "domainObject")
@ToString(exclude = "domainObject")
@NoArgsConstructor
//@JsonIgnoreProperties("domainObject")
@JsonFilter("myEntityFilter")
public abstract class Entity<T extends DomainObject> {
    @TimeToLive
    protected final static long TIME_TO_LIVE = 60 * 60 * 24;

    @Id
    @Indexed
    private String id;

//    @Transient
//    @JsonIgnore
    private T domainObject;

    public Entity(@NotNull T domainObject) {
        this.domainObject = domainObject;
    }

    public abstract Entity<T> createFromDomainObject(@NotNull T domainObject);

    public abstract void updateFromDomainObject(T domainObject);

    public void updateFromDomainObject() {
        this.updateFromDomainObject(this.getDomainObject());
    }

    public String getId() {
        return id;
    }

//    @Transient
//    @JsonIgnore
    public T getDomainObject() {
        return domainObject;
    }

    public void setDomainObject(T domainObject) {
        this.domainObject = domainObject;
    }
}

ThumbnailUrlListEntity.java

@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode(callSuper = false, exclude = "parentList")
@ToString(exclude = "parentList")
@RedisHash("thumbnail_url_entity")
//@JsonIgnoreProperties("parentList")
@JsonFilter("myThumbnailUrlEntityFilter")
public class ThumbnailUrlEntity extends Entity<ThumbnailUrl> {

    @Indexed
    private String url;

    private Integer priority;

//    @Transient
//    @JsonIgnore
    private ThumbnailUrlListEntity parentList;

    public ThumbnailUrlEntity(@NotNull ThumbnailUrl domainObject) {
        super(domainObject);
        this.updateFromDomainObject(domainObject);
    }

    @Override
    public Entity<ThumbnailUrl> createFromDomainObject(@NotNull ThumbnailUrl domainObject) {
        ThumbnailUrlEntity entity = new ThumbnailUrlEntity();
        entity.url = domainObject.getUrl();
        entity.priority = domainObject.getPriority();
        return entity;
    }

    @Override
    public void updateFromDomainObject(@NotNull ThumbnailUrl domainObject) {
        this.url = domainObject.getUrl();
        this.priority = domainObject.getPriority();
    }

    public String getUrl() {
        return url;
    }

    public Integer getPriority() {
        return priority;
    }

    public void setPriority(Integer priority) {
        this.priority = priority;
    }

//    @Transient
//    @JsonIgnore
    public ThumbnailUrlListEntity getParentList() {
        return parentList;
    }

    public void setParentList(ThumbnailUrlListEntity parentList) {
        this.parentList = parentList;
    }
}

RedisConfig.java

@Configuration
@EnableRedisRepositories(basePackages = "nlp.floschne.thumbnailAnnotator.db")
public class RedisConfig {

    @Bean
    RedisConnectionFactory connectionFactory() {
        return new LettuceConnectionFactory();
    }

    @Bean
    RedisTemplate<?, ?> redisTemplate(RedisConnectionFactory connectionFactory) {

        RedisTemplate<String, byte[]> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);
        template.setKeySerializer(new StringRedisSerializer());

        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
        mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);


        SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("domainObject");
        FilterProvider filters = new SimpleFilterProvider()
                .addFilter("myEntityFilter", theFilter)
                .addFilter("myThumbnailUrlEntityFilter", theFilter);

        mapper.setFilters(filters);


        template.setValueSerializer(new GenericJackson2JsonRedisSerializer(mapper));

        return template;
    }

    @Bean
    public RedisCustomConversions redisCustomConversions() {
        return new RedisCustomConversions(Arrays.asList(
                new EntityToBytesConverter(),
                new BytesToEntityConverter(),
                new ThumbnailUrlEntityToBytesConverter(),
                new BytesToThumbnailUrlEntityConverter()));
    }

    @WritingConverter
    public class EntityToBytesConverter implements Converter<Entity<?>, byte[]> {

        private final GenericJackson2JsonRedisSerializer serializer;

        public EntityToBytesConverter() {
            ObjectMapper mapper = new ObjectMapper();
            mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);

            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("domainObject");
            FilterProvider filters = new SimpleFilterProvider().addFilter("myEntityFilter", theFilter);

            mapper.setFilters(filters);

            serializer = new GenericJackson2JsonRedisSerializer(mapper);
        }

        @Override
        public byte[] convert(Entity value) {
            return serializer.serialize(value);
        }
    }

    @ReadingConverter
    public class BytesToEntityConverter implements Converter<byte[], Entity<?>> {

        private final GenericJackson2JsonRedisSerializer serializer;

        public BytesToEntityConverter() {
            ObjectMapper mapper = new ObjectMapper();
            mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);


            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("domainObject");
            FilterProvider filters = new SimpleFilterProvider().addFilter("myEntityFilter", theFilter);

            mapper.setFilters(filters);

            serializer = new GenericJackson2JsonRedisSerializer(mapper);
        }

        @Override
        public Entity convert(byte[] value) {
            return (Entity) serializer.deserialize(value);
        }
    }

    @WritingConverter
    public class ThumbnailUrlEntityToBytesConverter implements Converter<ThumbnailUrlEntity, byte[]> {

        private final GenericJackson2JsonRedisSerializer serializer;

        public ThumbnailUrlEntityToBytesConverter() {
            ObjectMapper mapper = new ObjectMapper();
            mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);

            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("parentList");
            FilterProvider filters = new SimpleFilterProvider().addFilter("myThumbnailUrlEntityFilter", theFilter);

            mapper.setFilters(filters);

            serializer = new GenericJackson2JsonRedisSerializer(mapper);
        }

        @Override
        public byte[] convert(ThumbnailUrlEntity value) {
            return serializer.serialize(value);
        }
    }

    @ReadingConverter
    public class BytesToThumbnailUrlEntityConverter implements Converter<byte[], ThumbnailUrlEntity> {

        private final GenericJackson2JsonRedisSerializer serializer;

        public BytesToThumbnailUrlEntityConverter() {
            ObjectMapper mapper = new ObjectMapper();
            mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
            mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);


            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("parentList");
            FilterProvider filters = new SimpleFilterProvider().addFilter("myThumbnailUrlEntityFilter", theFilter);

            mapper.setFilters(filters);

            serializer = new GenericJackson2JsonRedisSerializer(mapper);
        }

        @Override
        public ThumbnailUrlEntity convert(byte[] value) {
            return (ThumbnailUrlEntity) serializer.deserialize(value);
        }
    }
}

ThumbnailUrlRepository

public interface ThumbnailUrlEntityRepository extends CrudRepository<ThumbnailUrlEntity, String> {
}

带有异常的 StackTrace

org.springframework.data.keyvalue.core.UncategorizedKeyValueException: Path to property must not be null or empty.; nested exception is java.lang.IllegalArgumentException: Path to property must not be null or empty.

    at org.springframework.data.keyvalue.core.KeyValuePersistenceExceptionTranslator.translateExceptionIfPossible(KeyValuePersistenceExceptionTranslator.java:55)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.resolveExceptionIfPossible(KeyValueTemplate.java:459)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.execute(KeyValueTemplate.java:345)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.insert(KeyValueTemplate.java:158)
    at org.springframework.data.redis.core.RedisKeyValueTemplate.insert(RedisKeyValueTemplate.java:125)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.insert(KeyValueTemplate.java:140)
    at org.springframework.data.keyvalue.repository.support.SimpleKeyValueRepository.save(SimpleKeyValueRepository.java:101)
    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.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:377)
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:629)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:593)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:578)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
    at com.sun.proxy.$Proxy43.save(Unknown Source)
    at nlp.floschne.thumbnailAnnotator.db.repository.ThumbnailUrlEntityRepositoryTests.whenSaving_thenAvailableOnRetrieval(ThumbnailUrlEntityRepositoryTests.java:34)
    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.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:73)
    at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:83)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    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.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
    at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$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.IllegalArgumentException: Path to property must not be null or empty.
    at org.springframework.util.Assert.hasText(Assert.java:276)
    at org.springframework.data.redis.core.convert.Bucket.put(Bucket.java:72)
    at org.springframework.data.redis.core.convert.MappingRedisConverter.writeToBucket(MappingRedisConverter.java:750)
    at org.springframework.data.redis.core.convert.MappingRedisConverter.writeInternal(MappingRedisConverter.java:571)
    at org.springframework.data.redis.core.convert.MappingRedisConverter.write(MappingRedisConverter.java:396)
    at org.springframework.data.redis.core.convert.MappingRedisConverter.write(MappingRedisConverter.java:122)
    at org.springframework.data.redis.core.RedisKeyValueAdapter.put(RedisKeyValueAdapter.java:208)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.lambda$insert$0(KeyValueTemplate.java:165)
    at org.springframework.data.keyvalue.core.KeyValueTemplate.execute(KeyValueTemplate.java:343)
    ... 58 more

更新我尝试使用自定义序列化程序（参见下面的代码）并在我的 RedisConfig 中配置它（再次参见下面的代码），但这仍然没有帮助，我得到完全相同的异常..

顺便说一句，我已经在此处考虑了“Christoph Strobl”的答案：spring-data-redis Jackson serialization :-)

EntityJsonSerializer.java

 public class EntityJsonSerializer implements RedisSerializer<Entity> {

        private final ObjectMapper mapper;

        public EntityJsonSerializer() {
            this.mapper = new ObjectMapper();
            this.mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
            this.mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            this.mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
            this.mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
            this.mapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_EMPTY);


            SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("domainObject", "parentList");

            FilterProvider filters = new SimpleFilterProvider()
                    .addFilter("myEntityFilter", theFilter)
                    .addFilter("myThumbnailUrlEntityFilter", theFilter);

            this.mapper.setFilters(filters);
        }

        public EntityJsonSerializer(ObjectMapper mapper) {
            this.mapper = mapper;
        }

        @Override
        public byte[] serialize(Entity t) throws SerializationException {
            try {
                return mapper.writeValueAsBytes(t);
            } catch (JsonProcessingException e) {
                throw new SerializationException(e.getMessage(), e);
            }
        }

        @Override
        public Entity deserialize(byte[] bytes) throws SerializationException {

            if (bytes == null) {
                return null;
            }

            try {
                return mapper.readValue(bytes, Entity.class);
            } catch (Exception e) {
                throw new SerializationException(e.getMessage(), e);
            }
        }
    }

更新了 RedisConfig.java

@Configuration
@EnableRedisRepositories(basePackages = "nlp.floschne.thumbnailAnnotator.db")
public class RedisConfig {

    @Bean
    RedisConnectionFactory connectionFactory() {
        return new LettuceConnectionFactory();
    }

    @Bean
    RedisTemplate<?, ?> redisTemplate(RedisConnectionFactory connectionFactory) {

        RedisTemplate<String, byte[]> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);
        template.setKeySerializer(new StringRedisSerializer());

        template.setValueSerializer(new EntityJsonSerializer());

        return template;
    }

    @Bean
    public RedisCustomConversions redisCustomConversions() {
        return new RedisCustomConversions(Arrays.asList(
                new EntityToBytesConverter(),
                new BytesToEntityConverter(),
                new ThumbnailUrlEntityToBytesConverter(),
                new BytesToThumbnailUrlEntityConverter()));
    }

    @WritingConverter
    public class EntityToBytesConverter implements Converter<Entity<?>, byte[]> {

        private final EntityJsonSerializer serializer;

        public EntityToBytesConverter() {
            serializer = new EntityJsonSerializer();
        }

        @Override
        public byte[] convert(Entity value) {
            return serializer.serialize(value);
        }
    }

    @ReadingConverter
    public class BytesToEntityConverter implements Converter<byte[], Entity<?>> {

        private final EntityJsonSerializer serializer;

        public BytesToEntityConverter() {
            serializer = new EntityJsonSerializer();
        }

        @Override
        public Entity convert(byte[] value) {
            return (Entity) serializer.deserialize(value);
        }
    }

    @WritingConverter
    public class ThumbnailUrlEntityToBytesConverter implements Converter<ThumbnailUrlEntity, byte[]> {

        private final EntityJsonSerializer serializer;

        public ThumbnailUrlEntityToBytesConverter() {
            serializer = new EntityJsonSerializer();
        }

        @Override
        public byte[] convert(ThumbnailUrlEntity value) {
            return serializer.serialize(value);
        }
    }

    @ReadingConverter
    public class BytesToThumbnailUrlEntityConverter implements Converter<byte[], ThumbnailUrlEntity> {

        private final EntityJsonSerializer serializer;

        public BytesToThumbnailUrlEntityConverter() {
            serializer = new EntityJsonSerializer();
        }

        @Override
        public ThumbnailUrlEntity convert(byte[] value) {
            return (ThumbnailUrlEntity) serializer.deserialize(value);
        }
    }
}

【问题讨论】：

使用@jsonignore。您的错误与序列化无关。
如前所述，我之前尝试过，但没有帮助。而且我很确定问题出在 Redis 序列化的某个地方，因为我尝试在没有 Redis 的情况下进行序列化（只需使用 Jackson 的字符串）并且忽略属性或自定义 ObjectMapper 的注释完美地工作..只有当我尝试这样做时使用 Spring Data Redis，我遇到了这些问题。
也试试@transient注解
是的，我也尝试过@Transient :) 问题在于，它不会忽略该属性，而是在序列化时将其设置为 null。我想完全摆脱财产
他们的文档说对象的基本接口序列化和反序列化为字节数组（二进制数据）。建议将实现设计为在序列化和反序列化方面处理空对象/空数组。请注意，Redis 不接受 null 键或值，但可以返回 null 回复（对于不存在的键）。

标签： java spring redis jackson

【解决方案1】：

我认为您可以执行以下操作之一：

首先，您可以尝试让当前版本工作，这似乎并不容易。

您是否为 Redis 配置了正确的 serializer？在链接上有这个答案：

使用 StringRedisTemplate 替换 RedisTemplate。

默认情况下，RedisTemplate 使用 Java 序列化，StringRedisTemplate 使用 StringRedisSerializer。

这也可以解决你的问题...

为 Redis 使用专用 POJO 的第二个选项。您可以手动进行值交换，也可以使用 Java bean 映射器，例如 MapStruct。

第三种选择可能是使用自定义serializer

【讨论】：

感谢您的回答！我刚刚通读了 MapStruct 文档，我想我会坚持下去