先上问题：

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)

at com.ppdai.realtime.datachannel.pullservice.dataproviders.bohai.BohaiQueryProvider.afterGetData(BohaiQueryProvider.groovy:395)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:210)

at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:59)

at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:52)

at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:154)

at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:166)

看问题原因是序列化对象的时候使用的是 StringRedisSerializer, 本来以为是因为AutoConfig 导致加载了系统默认的RedisTemplate， 而自己定义了RedisTemplate没有加载，

但是非常疑惑的一点是默认的RedisTemplate使用的是 JdkSerializationRedisSerializer(如下代码)，上面异常报的是使用redis value 使用StringRedisSerializer 导致的类型转化失败

public voidafterPropertiesSet() {super.afterPropertiesSet();boolean defaultUsed = false;if (defaultSerializer == null) {

defaultSerializer= newJdkSerializationRedisSerializer(

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(this);

}

initialized= true;

}

最后通过Alt + F7 (Find Usage) 发现下面这个代码

private Long incr(String key, longdelta){

RedisTemplate redisTemplate=getRedisTemplate()

ValueOperations operations =redisTemplate.opsForValue()

redisTemplate.setKeySerializer(newStringRedisSerializer())

redisTemplate.setValueSerializer(newStringRedisSerializer())returnoperations.increment(key, delta)

}

原来就是这里搞得鬼，将redisTemplate的ValueSerializer设置成了 StringRedisSerializer ，StringRedisSerializer参数是String类型的，因此就出现了类型转化错误。

附说明

redisTemplate需要序列化key,value,hashkey,hashvalue,  提供了很多序列化工具，什么Jackson、FastJson、JDKSerialization 也可以自己定义。

redisTamplate默认这四种都使用JDKSerialization做序列化，如果没有提供定义默认都用JDK。