Question

我是一个很新的人，他想尝试从EntryProcessor中“缓存”缓存，但是无法遍历应用程序中ScanQuery的结果

我已经点燃了带有两个原子分区缓存并启用了对等类加载的ignite v2.6.0集群：

Cache A : IgniteCache<Long, A>
Cache B : IgniteCache<UUID, ScheduledTask>


interface ScheduledTask extends Serializable {
     Instant getExecuteAt()
}

one of classes that are stored in cache B:

class ExpirationTask implements ScheduledTask

Spring启动应用程序（用Kotlin写）对缓存A异步调用入口处理器。处理器在两个缓存（A和B）中填充数据。然后应用程序查询缓存B：

 val dueQuery = ScanQuery<UUID, ScheduledTask> { _, task -> task.executeAt <= now }

       bCache.query(dueQuery, { it.key }).use { taskKeys ->
            for (taskKey in taskKeys) {
   ………………………
          }
}

但是查询游标会抛出ClassCastException：

Caused by: java.lang.ClassCastException: ExpirationTask cannot be cast to ScheduledTask
    at ….Scheduler$poll$dueQuery$1.apply(Scheduler:61)
    at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager$ScanQueryIterator.advance(GridCacheQueryManager.java:3089)
    at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager$ScanQueryIterator.onHasNext(GridCacheQueryManager.java:2982)
    at org.apache.ignite.internal.util.GridCloseableIteratorAdapter.hasNextX(GridCloseableIteratorAdapter.java:53)
    at org.apache.ignite.internal.util.lang.GridIteratorAdapter.hasNext(GridIteratorAdapter.java:45)
    at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager.runQuery(GridCacheQueryManager.java:1164)
    at org.apache.ignite.internal.processors.cache.query.GridCacheDistributedQueryManager.processQueryRequest(GridCacheDistributedQueryManager.java:230)
    at org.apache.ignite.internal.processors.cache.query.GridCacheDistributedQueryManager$2.apply(GridCacheDistributedQueryManager.java:108)
    at org.apache.ignite.internal.processors.cache.query.GridCacheDistributedQueryManager$2.apply(GridCacheDistributedQueryManager.java:106)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager.processMessage(GridCacheIoManager.java:1054)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager.onMessage0(GridCacheIoManager.java:579)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager.handleMessage(GridCacheIoManager.java:378)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager.handleMessage(GridCacheIoManager.java:304)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager.access$100(GridCacheIoManager.java:99)
    at org.apache.ignite.internal.processors.cache.GridCacheIoManager$1.onMessage(GridCacheIoManager.java:293)
    at org.apache.ignite.internal.managers.communication.GridIoManager.invokeListener(GridIoManager.java:1556)
    at org.apache.ignite.internal.managers.communication.GridIoManager.processRegularMessage0(GridIoManager.java:1184)
    at org.apache.ignite.internal.managers.communication.GridIoManager.access$4200(GridIoManager.java:125)
    at org.apache.ignite.internal.managers.communication.GridIoManager$9.run(GridIoManager.java:1091)
    ... 3 common frames omitted

由于自定义序列化，A和B类都由OptimizedMarshaller封送，

data class B(val dueTime: Instant, val id: Long) : ScheduledTask {

 override fun getExecuteAt(): Instant {
        return dueTime
    }
    private fun writeObject(stream: ObjectOutputStream) {
        // Only used to indicate custom serialization for Ignite. Real work done by writeReplace()
    }

    private fun readObject(stream: ObjectInputStream) {
        // Only used to indicate custom serialization for Ignite. Real work done by writeReplace()
    }

    private fun writeReplace(): Any = Serializer(this)

    class Serializer @JvmOverloads constructor(var source: B? = null) : Externalizable {
        override fun readExternal(stream: ObjectInput) {
            val dueTime = stream.readObject() as Instant
            val id = stream.readLong()
           source = B(dueTime, id)
        }

        override fun writeExternal(stream: ObjectOutput) {
            stream.writeObject(source!!.dueTime)
            stream.writeLong(source!!.id)
       }

        private fun readResolve(): Any = source!!

        companion object {
            private const val serialVersionUID: Long = 1
        }
    }

    companion object {
        private const val serialVersionUID: Long = 42
    }
}

所以我正在寻找一种对缓存值执行多态查询的方法。

谢谢

Answer 1

Ignite不会对等加载缓存键/值类型，因此您不必为此担心。
是否有可能由不同的类加载器加载了B？您可以通过检查B的getClass().getClassLoader()来进行调试。
也许Kotlin希望在某个时候包装B型？

QueryCursor中的点燃序列化问题

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