redisTemplate 键值序列化策略

redisTemplate 键值序列化策略

RedisSerializer<T> StringRedisSerializer JdkSerializationRedisSerializer

keySerializer valueSerializer hashKeySerializer hashValueSerializer

public class RedisTemplate<K, V> extends RedisAccessor implements RedisOperations<K, V>, BeanClassLoaderAware {

    private boolean enableDefaultSerializer = true;
    private RedisSerializer<?> defaultSerializer;

    private RedisSerializer keySerializer = null;
    private RedisSerializer valueSerializer = null;
    private RedisSerializer hashKeySerializer = null;
    private RedisSerializer hashValueSerializer = null;
    private RedisSerializer<String> stringSerializer = new StringRedisSerializer();

    /* redisTemplate 默认的序列化策略 */
    public void afterPropertiesSet() {

        super.afterPropertiesSet();

        boolean defaultUsed = false;

        if (defaultSerializer == null) {

            defaultSerializer = new JdkSerializationRedisSerializer(
                classLoader != null ? classLoader : this.getClass().getClassLoader());
        }

        if (enableDefaultSerializer) {

            if (keySerializer == null) {
                keySerializer = defaultSerializer;
                defaultUsed = true;
            }
            if (valueSerializer == null) {
                valueSerializer = defaultSerializer;
                defaultUsed = true;
            }
            if (hashKeySerializer == null) {
                hashKeySerializer = defaultSerializer;
                defaultUsed = true;
            }
            if (hashValueSerializer == null) {
                hashValueSerializer = defaultSerializer;
                defaultUsed = true;
            }
        }
        //启用默认序列化器并且默认序列化器被使用，检查默认序列化器为 null ，则序列化器没有全部初始化成功。
        if (enableDefaultSerializer && defaultUsed) {
            Assert.notNull(defaultSerializer, "default serializer null and not all serializers initialized");
        }

        if (scriptExecutor == null) {
            this.scriptExecutor = new DefaultScriptExecutor<K>(this);
        }

        initialized = true;
    }
}

keySerializer 字符串 哈希 列表 集合 有序集合的键的序列化策略。
valueSerializer 字符串 列表 集合 有序集合的值的序列化策略。
hashKeySerializer 哈希的小键的序列化策略
hashValueSerializer 哈希的值的序列化策略

StringRedisSerializer  只能是 String 对象
JdkSerializationRedisSerializer 实现了序列化接口的对象。

String 类型

RedisSerializer<T> 将一个对象序列化字节数组，存入 redis 。将 redis 得到的字节数组反序列化成对象。

public interface RedisSerializer<T> {
    byte[] serialize(T t) throws SerializationException;
    T deserialize(byte[] bytes) throws SerializationException;
}

@Test
public void testStrCR(){
    redisTemplate.boundValueOps("用户名").set("刘备");
    String username = (String) redisTemplate.boundValueOps("用户名").get();
    System.out.println(username);//刘备
}

@Test
public void testStrD(){
    redisTemplate.delete("用户名");
}

127.0.0.1:6379> keys *
1) "\xe7\x94\xa8\xe6\x88\xb7\xe5\x90\x8d" UTF-8 用户名
2) "\xd3\xc3\xbb\xa7\xc3\xfb" GBK 用户名
127.0.0.1:6379> get "\xd3\xc3\xbb\xa7\xc3\xfb" GBK 用户名
"\xe5\x88\x98\xe5\xa4\x87" UTF-8 刘备
127.0.0.1:6379> get "\xe7\x94\xa8\xe6\x88\xb7\xe5\x90\x8d"  UTF-8 用户名
"\xe5\x88\x98\xe5\xa4\x87" UTF-8 刘备

/*
    可见 redis 命令行打印就是字节数组的16进制形式。中文字符串 + 编码 = 字节数组。客户端发送给 redis 的是字节数组。
*/
@Test
public void x3() throws UnsupportedEncodingException {
    byte[] bytesUTF8 = "用户名".getBytes("UTF-8");
    System.out.println(bytesToHexString(bytesUTF8));//e794a8e688b7e5908d
    byte[] bytesGBK = "用户名".getBytes("GBK");
    System.out.println(bytesToHexString(bytesGBK));//d3c3bba7c3fb
    byte[] bytes= "刘备".getBytes("UTF-8");
    System.out.println(bytesToHexString(bytes));//e58898e5a487
}

常用字节转换（字符串转16进制，16进制转字符串）https://blog.csdn.net/yyz_1987/article/details/80634224

public static String bytesToHexString(byte[] src){
    StringBuilder stringBuilder = new StringBuilder("");
    if (src == null || src.length <= 0) {
        return null;
    }
    for (int i = 0; i < src.length; i++) {
        int v = src[i] & 0xFF;
        String hv = Integer.toHexString(v);
        if (hv.length() < 2) {
            stringBuilder.append(0);
        }
        stringBuilder.append(hv);
    }
    return stringBuilder.toString();
}
//原文：https://blog.csdn.net/yyz_1987/article/details/80634224 

package org.springframework.data.redis.serializer;

public class StringRedisSerializer implements RedisSerializer<String> {

    private final Charset charset;

    public StringRedisSerializer() {
        this(Charset.forName("UTF8"));
    }

    public StringRedisSerializer(Charset charset) {
        Assert.notNull(charset);
        this.charset = charset;
    }

    public String deserialize(byte[] bytes) {
        return (bytes == null ? null : new String(bytes, charset));
    }

    public byte[] serialize(String string) {
        return (string == null ? null : string.getBytes(charset));
    }
}

修改 redisTemplate 键值的序列化策略

<!-- 配置RedisTemplate -->
<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
    <property name="connectionFactory" ref="jedisConnectionFactory"/>

    <!-- 序列化策略 推荐使用StringRedisSerializer ，可以通过构造参数指定字符集，默认为 UTF-8 -->
    <property name="keySerializer">
        <bean class="org.springframework.data.redis.serializer.StringRedisSerializer">
            <constructor-arg ref="gbkCharSet" />
        </bean>
    </property>
    <property name="valueSerializer">
        <bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
    </property>

    <property name="hashKeySerializer">
        <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer"/>
    </property>
    <property name="hashValueSerializer">
        <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer"/>
    </property>
</bean>

package com.mozq.charset;

import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

import java.nio.charset.Charset;

//@Component
@Configuration
public class CharSetUtil {

    @Bean("gbkCharSet")
    public Charset gbkCharSet(){
        return Charset.forName("GBK");
    }

}