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/* * Copyright 2015-2019 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.data.redis.serializer; import java.io.IOException; import org.springframework.cache.support.NullValue; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.StringUtils; import com.fasterxml.jackson.annotation.JsonTypeInfo; import com.fasterxml.jackson.annotation.JsonTypeInfo.As; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectMapper.DefaultTyping; import com.fasterxml.jackson.databind.SerializerProvider; import com.fasterxml.jackson.databind.module.SimpleModule; import com.fasterxml.jackson.databind.ser.SerializerFactory; import com.fasterxml.jackson.databind.ser.std.StdSerializer; /** * Generic Jackson 2-based {@link RedisSerializer} that maps {@link Object objects} to JSON using dynamic typing. * * @author Christoph Strobl * @author Mark Paluch * @since 1.6 */ public class GenericJackson2JsonRedisSerializer implements RedisSerializer<Object> { private final ObjectMapper mapper; /** * Creates {@link GenericJackson2JsonRedisSerializer} and configures {@link ObjectMapper} for default typing. */ public GenericJackson2JsonRedisSerializer() { this((String) null); } /** * Creates {@link GenericJackson2JsonRedisSerializer} and configures {@link ObjectMapper} for default typing using the * given {@literal name}. In case of an {@literal empty} or {@literal null} String the default * {@link JsonTypeInfo.Id#CLASS} will be used. * * @param classPropertyTypeName Name of the JSON property holding type information. Can be {@literal null}. */ public GenericJackson2JsonRedisSerializer(@Nullable String classPropertyTypeName) { this(new ObjectMapper()); // 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. registerNullValueSerializer(mapper, classPropertyTypeName); if (StringUtils.hasText(classPropertyTypeName)) { mapper.enableDefaultTypingAsProperty(DefaultTyping.NON_FINAL, classPropertyTypeName); } else { mapper.enableDefaultTyping(DefaultTyping.NON_FINAL, As.PROPERTY); } } /** * Setting a custom-configured {@link ObjectMapper} is one way to take further control of the JSON serialization * process. For example, an extended {@link SerializerFactory} can be configured that provides custom serializers for * specific types. * * @param mapper must not be {@literal null}. */ public GenericJackson2JsonRedisSerializer(ObjectMapper mapper) { Assert.notNull(mapper, "ObjectMapper must not be null!"); this.mapper = mapper; } /** * Register {@link NullValueSerializer} in the given {@link ObjectMapper} with an optional * {@code classPropertyTypeName}. This method should be called by code that customizes * {@link GenericJackson2JsonRedisSerializer} by providing an external {@link ObjectMapper}. * * @param objectMapper the object mapper to customize. * @param classPropertyTypeName name of the type property. Defaults to {@code @class} if {@literal null}/empty. * @since 2.2 */ public static void registerNullValueSerializer(ObjectMapper objectMapper, @Nullable String classPropertyTypeName) { // 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().addSerializer(new NullValueSerializer(classPropertyTypeName))); } /* * (non-Javadoc) * @see org.springframework.data.redis.serializer.RedisSerializer#serialize(java.lang.Object) */ @Override public byte[] serialize(@Nullable Object source) throws SerializationException { if (source == null) { return SerializationUtils.EMPTY_ARRAY; } try { return mapper.writeValueAsBytes(source); } catch (JsonProcessingException e) { throw new SerializationException("Could not write JSON: " + e.getMessage(), e); } } /* * (non-Javadoc) * @see org.springframework.data.redis.serializer.RedisSerializer#deserialize(byte[]) */ @Override public Object deserialize(@Nullable byte[] source) throws SerializationException { return deserialize(source, Object.class); } /** * @param source can be {@literal null}. * @param type must not be {@literal null}. * @return {@literal null} for empty source. * @throws SerializationException */ @Nullable public <T> T deserialize(@Nullable byte[] source, Class<T> type) throws SerializationException { Assert.notNull(type, "Deserialization type must not be null! Pleaes provide Object.class to make use of Jackson2 default typing."); if (SerializationUtils.isEmpty(source)) { return null; } try { return mapper.readValue(source, type); } catch (Exception ex) { throw new SerializationException("Could not read JSON: " + ex.getMessage(), ex); } } /** * {@link StdSerializer} adding class information required by default typing. This allows de-/serialization of * {@link NullValue}. * * @author Christoph Strobl * @since 1.8 */ 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(@Nullable String classIdentifier) { super(NullValue.class); this.classIdentifier = StringUtils.hasText(classIdentifier) ? classIdentifier : "@class"; } /* * (non-Javadoc) * @see com.fasterxml.jackson.databind.ser.std.StdSerializer#serialize(java.lang.Object, com.fasterxml.jackson.core.JsonGenerator, com.fasterxml.jackson.databind.SerializerProvider) */ @Override public void serialize(NullValue value, JsonGenerator jgen, SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeStringField(classIdentifier, NullValue.class.getName()); jgen.writeEndObject(); } } }