为什么 apache ignite 没有反序列化 java.util.Collections$SetFromMap？

Question

Apache 当我尝试将数据放入缓存时，ignite 抛出以下异常，

Caused by: class org.apache.ignite.IgniteCheckedException: Failed to deserialize object with given class loader: [clsLdr=org.apache.ignite.internal.processors.cache.GridCacheDeploymentManager$CacheClassLoader@5d5b5fa7, err=Failed to deserialize object [typeName=java.util.Collections$SetFromMap]]
    Caused by: java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.apache.ignite.internal.marshaller.optimized.OptimizedObjectInputStream.readSerializable(OptimizedObjectInputStream.java:608)
        ... 43 more
    Caused by: java.lang.ClassNotFoundException: com.example.springapachecache.HelloWorld$1

程序：

 package com.example.springapachecache;

 import org.apache.ignite.Ignite;
 import org.apache.ignite.IgniteCache;
 import org.apache.ignite.IgniteException;
 import org.apache.ignite.Ignition;
 import org.apache.ignite.configuration.IgniteConfiguration;
 import org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi;
 import org.apache.ignite.spi.discovery.tcp.ipfinder.multicast.TcpDiscoveryMulticastIpFinder;

 import java.util.*;

 public class HelloWorld {
 public static void main(String[] args) throws IgniteException {
    // Preparing IgniteConfiguration using Java APIs
    IgniteConfiguration cfg = new IgniteConfiguration();

    // The node will be started as a client node.
    cfg.setClientMode(true);

    // Classes of custom Java logic will be transferred over the wire from this app.
    cfg.setPeerClassLoadingEnabled(true);

    // Setting up an IP Finder to ensure the client can locate the servers.
    TcpDiscoveryMulticastIpFinder ipFinder = new TcpDiscoveryMulticastIpFinder();
    ipFinder.setAddresses(Collections.singletonList("127.0.0.1:47500..47509"));
    cfg.setDiscoverySpi(new TcpDiscoverySpi().setIpFinder(ipFinder));

    // Starting the node
    Ignite ignite = Ignition.start(cfg);
    IgniteCache<Integer, Set<String>> setCache = ignite.getOrCreateCache("mySetCache");
    System.out.println("setCache before: "+setCache.get(1));
    Set<String> meetingUuids = Collections.newSetFromMap(new LinkedHashMap<String, Boolean>() {
        // Set backed by LRU map.
        private static final long serialVersionUID = -8251614405342939979L;
        @Override
        protected boolean removeEldestEntry(Map.Entry<String, Boolean> eldest) {
            return size() > 1000;
        }
    });

    meetingUuids.add("meetingId");
   //        Set<String> meetingUuidSet = new HashSet<>(meetingUuids);
   //        setCache.put(3, meetingUuidSet);
    setCache.put(1, meetingUuids);
    System.out.println("setCache after: "+setCache.get(1));

    // Disconnect from the cluster.
    ignite.close();
}

}

使用简单的 linkedHashMap(Set meetingUuids = Collections.newSetFromMap(new LinkedHashMap<String, Boolean>()) 构建 Set 工作正常。你能帮忙吗？

Answer 1

你在最后一段中暗示了这个问题。 你可以在 Ignite 中存储 Sets，你可以在 .network 上“peer class load”代码。 您不能做的是对等 class 加载您的“模型”中使用的代码，即用于定义缓存的任何 class。 在您的示例代码中，这是Collections.newSetFromMap中的闭包。

我认为将自定义 Set 存储在 Ignite 中有点混乱。 例如，您不能使用 SQL 查询 collections。 所以最好的解决方案是 model 你的数据不同。

如果你真的想要 go 这条路线，如果你把你的 class 的副本放在服务器端它应该可以工作。