Redis序列化对象的时候报错如下
java.lang.ClassCastException: com.ppdai.cbd.ddp.thirdparty.contract.bhxtzx.BHXTZXTask cannot be cast to java.lang.String
at org.springframework.data.redis.serializer.StringRedisSerializer.serialize(StringRedisSerializer.java:33)
at org.springframework.data.redis.core.AbstractOperations.rawValue(AbstractOperations.java:117)
at org.springframework.data.redis.core.DefaultListOperations.leftPush(DefaultListOperations.java:71)
at org.springframework.data.redis.core.DefaultBoundListOperations.leftPush(DefaultBoundListOperations.java:60)
at com.ppdai.realtime.datachannel.pullservice.entity.RedisQueue.pushFromHead(RedisQueue.java:63)
at com.ppdai.realtime.datachannel.pullservice.redisconfig.RedisTaskSender.sendTask(RedisTaskSender.java:35)
at com.ppdai.realtime.datachannel.pullservice.redisconfig.RedisTaskSender$sendTask.call(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
BHXTZXTask是自己定义的Bean,因此问题就变成了自定义的对象不能转成String对象,为什么会需要转成String对象呢
因为redis默认使用jdkSerializer,看RedisTemplate的代码如下,
afterPropertiesSet函数
public class RedisTemplate<K, V> extends RedisAccessor implements RedisOperations<K, V>, BeanClassLoaderAware {
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;
}
}
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;
}
}
查看源码,如下,通过rawValue()函数获取序列化之后的字节码
public Long leftPush(K key, V value) {
final byte[] rawKey = rawKey(key);
final byte[] rawValue = rawValue(value);
return execute(new RedisCallback<Long>() {
public Long doInRedis(RedisConnection connection) {
return connection.lPush(rawKey, rawValue);
}
}, true);
}
private byte[] rawValue(Object value) { if (valueSerializer == null && value instanceof byte[]) { return (byte[]) value; } return valueSerializer.serialize(value);}
通过 valueSerializer序列化来序列化对象, redis如果不配置,默认 valueSerializer的序列化是会使用
StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
JdkSerializationRedisSerializer jdkSerializationRedisSerializer = new JdkSerializationRedisSerializer();
System.out.println(redisTemplate.hasKey("bohai_credit"));
redisTemplate.delete("bohai_credit");
System.out.println(stringRedisSerializer.serialize("bohai_credit"));
System.out.println(jdkSerializationRedisSerializer.serialize("bohai_credit"));
[B@21831984
[B@4488db1f
运行结果如上所示。