Redis序列化對象的時候報錯如下
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是自己定義的Bean,因此問題就變成了自定義的對象不能轉成String對象,為什么會需要轉成String對象呢
因為redis默認使用jdkSerializer,看RedisTemplate的代碼如下,
afterPropertiesSet函數
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; } }
查看源碼,如下,通過rawValue()函數獲取序列化之后的字節碼
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);
}
通過 valueSerializer序列化來序列化對象, redis如果不配置,默認 valueSerializer的序列化是會使用
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
運行結果如上所示。