java - Spring Boot + Infinispan Embedded - 当要缓存的对象已被修改时如何防止 ClassCastException？

Question

我有一个带有 Spring Boot 2.5.5 和嵌入式 Infinispan 12.1.7 的 Web 应用程序。

我有一个带有端点的控制器，可以通过 ID 获取 Person 对象：

@RestController
public class PersonController {

    private final PersonService service;

    public PersonController(PersonService service) {
        this.service = service;
    }

    @GetMapping("/person/{id}")
    public ResponseEntity<Person> getPerson(@PathVariable("id") String id) {
        Person person = this.service.getPerson(id);
        return ResponseEntity.ok(person);
    }
}

以下是在方法上PersonService使用@Cacheable注解的实现getPerson：

public interface PersonService {

    Person getPerson(String id);
}

@Service
public class PersonServiceImpl implements PersonService {

    private static final Logger LOG = LoggerFactory.getLogger(PersonServiceImpl.class);

    @Override
    @Cacheable("person")
    public Person getPerson(String id) {
        LOG.info("Get Person by ID {}", id);

        Person person = new Person();
        person.setId(id);
        person.setFirstName("John");
        person.setLastName("Doe");
        person.setAge(35);
        person.setGender(Gender.MALE);
        person.setExtra("extra value");

        return person;
    }
}

这是 Person 类：

public class Person implements Serializable {

    private static final long serialVersionUID = 1L;

    private String id;
    private String firstName;
    private String lastName;
    private Integer age;
    private Gender gender;
    private String extra;

    /* Getters / Setters */
    ...
}

我将 infinispan 配置为使用基于文件系统的缓存存储：

<?xml version="1.0" encoding="UTF-8"?>
<infinispan xmlns="urn:infinispan:config:12.1"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="urn:infinispan:config:12.1 https://infinispan.org/schemas/infinispan-config-12.1.xsd">
    <cache-container default-cache="default">

        <serialization marshaller="org.infinispan.commons.marshall.JavaSerializationMarshaller">
            <allow-list>
                <regex>com.example.*</regex>
            </allow-list>
        </serialization>

        <local-cache-configuration name="mirrorFile">
            <persistence passivation="false">
                <file-store path="${infinispan.disk.store.dir}"
                            shared="false"
                            preload="false"
                            purge="false"
                            segmented="false">
                </file-store>
            </persistence>
        </local-cache-configuration>

        <local-cache name="person" statistics="true" configuration="mirrorFile">
            <memory max-count="500"/>
            <expiration lifespan="86400000"/>
        </local-cache>
    </cache-container>
</infinispan>

我请求端点获取 id 为“1”的人：
PersonService.getPerson(String)第一次调用 http://localhost:8090/assets-webapp/person/1 并缓存结果。
我再次请求端点以获取 id 为“1”的人，并在缓存中检索结果。

我通过使用 getter/setter 删除字段来更新Person对象，然后添加一个字段：extraextra2

public class Person implements Serializable {

    private static final long serialVersionUID = 1L;

    private String id;
    private String firstName;
    private String lastName;
    private Integer age;
    private Gender gender;
    private String extra2;

    ...

    public String getExtra2() {
        return extra2;
    }

    public void setExtra2(String extra2) {
        this.extra2 = extra2;
    }
}

我再次请求端点获取 id 为“1”的人，但ClassCastException抛出了 a：

java.lang.ClassCastException: com.example.controller.Person cannot be cast to com.example.controller.Person] with root cause java.lang.ClassCastException: com.example.controller.Person cannot be cast to com.example.controller.Person
    at com.example.controller.PersonServiceImpl$$EnhancerBySpringCGLIB$$ec42b86.getPerson(<generated>) ~[classes/:?]
    at com.example.controller.PersonController.getPerson(PersonController.java:19) ~[classes/:?]

extra2我通过删除字段并添加字段来回滚 Person 对象修改extra。
我再次请求端点获取 id 为“1”的人，但ClassCastException总是抛出a

infinispan 使用的编组器是JavaSerializationMarshaller。

我猜如果类已被重新编译，java 序列化不允许取消缓存数据。

但我想知道如何避免这种情况，尤其是能够在访问缓存数据时管理类的更新（添加/删除字段）而不会出现异常。

有没有人有办法解决吗？

标签： javaspringspring-bootcachinginfinispan

Answer 1

我终于创建了自己的 Marshaller，它在 JSON 中序列化/反序列化，受以下类的启发：GenericJackson2JsonRedisSerializer.java

public class JsonMarshaller extends AbstractMarshaller {

    private static final byte[] EMPTY_ARRAY = new byte[0];

    private final ObjectMapper objectMapper;

    public JsonMarshaller() {
        this.objectMapper = objectMapper();
    }

    private ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();

        objectMapper.enable(JsonGenerator.Feature.IGNORE_UNKNOWN);
        objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        objectMapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
        objectMapper.activateDefaultTyping(objectMapper.getPolymorphicTypeValidator(), ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);

        // Serialize/Deserialize objects from any fields or creators (constructors and (static) factory methods). Ignore getters/setters.
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
        objectMapper.setVisibility(PropertyAccessor.CREATOR, JsonAutoDetect.Visibility.ANY);
        objectMapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

        // Register support of other new Java 8 datatypes outside of date/time: most notably Optional, OptionalLong, OptionalDouble
        objectMapper.registerModule(new Jdk8Module());

        // Register support for Java 8 date/time types (specified in JSR-310 specification)
        objectMapper.registerModule(new JavaTimeModule());

        // simply setting {@code mapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS)} does not help here since we need
        // the type hint embedded for deserialization using the default typing feature.
        objectMapper.registerModule(new SimpleModule("NullValue Module").addSerializer(new NullValueSerializer(null)));

        objectMapper.registerModule(
                new SimpleModule("SimpleKey Module")
                        .addSerializer(new SimpleKeySerializer())
                        .addDeserializer(SimpleKey.class, new SimpleKeyDeserializer(objectMapper))
        );

        return objectMapper;
    }

    @Override
    protected ByteBuffer objectToBuffer(Object o, int estimatedSize) throws IOException, InterruptedException {
        return ByteBufferImpl.create(objectToBytes(o));
    }

    private byte[] objectToBytes(Object o) throws JsonProcessingException {
        if (o == null) {
            return EMPTY_ARRAY;
        }
        return objectMapper.writeValueAsBytes(o);
    }

    @Override
    public Object objectFromByteBuffer(byte[] buf, int offset, int length) throws IOException, ClassNotFoundException {
        if (isEmpty(buf)) {
            return null;
        }
        return objectMapper.readValue(buf, Object.class);
    }

    @Override
    public boolean isMarshallable(Object o) throws Exception {
        return true;
    }

    @Override
    public MediaType mediaType() {
        return MediaType.APPLICATION_JSON;
    }

    private static boolean isEmpty(byte[] data) {
        return (data == null || data.length == 0);
    }

    /**
     * {@link StdSerializer} adding class information required by default typing. This allows de-/serialization of {@link NullValue}.
     */
    private static class NullValueSerializer extends StdSerializer<NullValue> {

        private static final long serialVersionUID = 1999052150548658808L;
        private final String classIdentifier;

        /**
         * @param classIdentifier can be {@literal null} and will be defaulted to {@code @class}.
         */
        NullValueSerializer(String classIdentifier) {

            super(NullValue.class);
            this.classIdentifier = StringUtils.isNotBlank(classIdentifier) ? classIdentifier : "@class";
        }

        @Override
        public void serialize(NullValue value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
            jgen.writeStartObject();
            jgen.writeStringField(classIdentifier, NullValue.class.getName());
            jgen.writeEndObject();
        }
    }
}

SimpleKey 对象的序列化器/反序列化器：

public class SimpleKeySerializer extends StdSerializer<SimpleKey> {

    private static final Logger LOG = LoggerFactory.getLogger(SimpleKeySerializer.class);

    protected SimpleKeySerializer() {
        super(SimpleKey.class);
    }

    @Override
    public void serialize(SimpleKey simpleKey, JsonGenerator gen, SerializerProvider provider) throws IOException {
        gen.writeStartObject();
        serializeFields(simpleKey, gen, provider);
        gen.writeEndObject();
    }

    @Override
    public void serializeWithType(SimpleKey value, JsonGenerator gen, SerializerProvider provider, TypeSerializer typeSer) throws IOException {
        WritableTypeId typeId = typeSer.typeId(value, JsonToken.START_OBJECT);
        typeSer.writeTypePrefix(gen, typeId);
        serializeFields(value, gen, provider);
        typeSer.writeTypeSuffix(gen, typeId);

    }

    private void serializeFields(SimpleKey simpleKey, JsonGenerator gen, SerializerProvider provider) {
        try {
            Object[] params = (Object[]) FieldUtils.readField(simpleKey, "params", true);
            gen.writeArrayFieldStart("params");
            gen.writeObject(params);
            gen.writeEndArray();
        } catch (Exception e) {
            LOG.warn("Could not read 'params' field from SimpleKey {}: {}", simpleKey, e.getMessage(), e);
        }
    }
}

public class SimpleKeyDeserializer extends StdDeserializer<SimpleKey> {

    private final ObjectMapper objectMapper;

    public SimpleKeyDeserializer(ObjectMapper objectMapper) {
        super(SimpleKey.class);
        this.objectMapper = objectMapper;
    }

    @Override
    public SimpleKey deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
        List<Object> params = new ArrayList<>();
        TreeNode treeNode = jp.getCodec().readTree(jp);
        TreeNode paramsNode = treeNode.get("params");
        if (paramsNode.isArray()) {
            for (JsonNode paramNode : (ArrayNode) paramsNode) {
                Object[] values = this.objectMapper.treeToValue(paramNode, Object[].class);
                params.addAll(Arrays.asList(values));
            }
        }
        return new SimpleKey(params.toArray());
    }

}

我配置 infinispan 如下：

<?xml version="1.0" encoding="UTF-8"?>
<infinispan xmlns="urn:infinispan:config:12.1"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="urn:infinispan:config:12.1 https://infinispan.org/schemas/infinispan-config-12.1.xsd">
    <cache-container default-cache="default">

        <serialization marshaller="com.example.JsonMarshaller">
            <allow-list>
                <regex>com.example.*</regex>
            </allow-list>
        </serialization>

        <local-cache-configuration name="mirrorFile">
            <persistence passivation="false">
                <file-store path="${infinispan.disk.store.dir}"
                            shared="false"
                            preload="false"
                            purge="false"
                            segmented="false">
                </file-store>
            </persistence>
        </local-cache-configuration>

        <local-cache name="person" statistics="true" configuration="mirrorFile">
            <memory max-count="500"/>
            <expiration lifespan="86400000"/>
        </local-cache>
    </cache-container>
</infinispan>