Java tutorial
/* * Copyright 2011-2019 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 org.springframework.lang.Nullable; import org.springframework.util.ClassUtils; /** * Basic interface serialization and deserialization of Objects to byte arrays (binary data). It is recommended that * implementations are designed to handle null objects/empty arrays on serialization and deserialization side. Note that * Redis does not accept null keys or values but can return null replies (for non existing keys). * * @author Mark Pollack * @author Costin Leau * @author Christoph Strobl */ public interface RedisSerializer<T> { /** * Serialize the given object to binary data. * * @param t object to serialize. Can be {@literal null}. * @return the equivalent binary data. Can be {@literal null}. */ @Nullable byte[] serialize(@Nullable T t) throws SerializationException; /** * Deserialize an object from the given binary data. * * @param bytes object binary representation. Can be {@literal null}. * @return the equivalent object instance. Can be {@literal null}. */ @Nullable T deserialize(@Nullable byte[] bytes) throws SerializationException; /** * Obtain a {@link RedisSerializer} using java serialization.<br /> * <strong>Note:</strong> Ensure that your domain objects are actually {@link java.io.Serializable serializable}. * * @return never {@literal null}. * @since 2.1 */ static RedisSerializer<Object> java() { return java(null); } /** * Obtain a {@link RedisSerializer} using java serialization with the given {@link ClassLoader}.<br /> * <strong>Note:</strong> Ensure that your domain objects are actually {@link java.io.Serializable serializable}. * * @param classLoader the {@link ClassLoader} to use for deserialization. Can be {@literal null}. * @return new instance of {@link RedisSerializer}. Never {@literal null}. * @since 2.1 */ static RedisSerializer<Object> java(@Nullable ClassLoader classLoader) { return new JdkSerializationRedisSerializer(classLoader); } /** * Obtain a {@link RedisSerializer} that can read and write JSON using * <a href="https://github.com/FasterXML/jackson-core">Jackson</a>. * * @return never {@literal null}. * @since 2.1 */ static RedisSerializer<Object> json() { return new GenericJackson2JsonRedisSerializer(); } /** * Obtain a simple {@link java.lang.String} to {@literal byte[]} (and back) serializer using * {@link java.nio.charset.StandardCharsets#UTF_8 UTF-8} as the default {@link java.nio.charset.Charset}. * * @return never {@literal null}. * @since 2.1 */ static RedisSerializer<String> string() { return StringRedisSerializer.UTF_8; } /** * Obtain a {@link RedisSerializer} that passes thru {@code byte[]}. * * @return never {@literal null}. * @since 2.2 */ static RedisSerializer<byte[]> byteArray() { return ByteArrayRedisSerializer.INSTANCE; } default boolean canSerialize(Class<?> type) { return ClassUtils.isAssignable(getTargetType(), type); } default Class<?> getTargetType() { return Object.class; } }