我正在使用Ignite将K-V类型为String-String的缓存值存储在名为“ DOCIDS”的缓存中。
我将HashMap的二进制转换对象用作另一个名为“ URLS”的K-V缓存中的值。密钥将仅是字符串，但值将为“ com.xyz.scrapy.common.ignite.IgniteObject”。
现在，当我查询扫描操作时，我正在这样做
//This scan query should only happen on cache which has K-V types as String-String.
public Object scan(Object... allObjects) throws Exception {
Set<Object> matchedKeys = new HashSet<>();
try (QueryCursor<Cache.Entry<String, String>> cursor =
cacheHolder.getSecondaryCache().query(new ScanQuery<>(
(k, v) -> k.contains(allObjects[0].toString())
))) {
for (Cache.Entry<String, String> entry : cursor) {
matchedKeys.add(entry.getKey());
}
}
return matchedKeys;
}
在allObjects中，该值将始终为某些String模式。那是肯定的。但是，当Ignite筛选这些值时，某个地方的值就是IgniteObject类型，而我并不是首先将其插入“ DOCIDS”缓存中。附件如下：
"com.xyz.scrapy.common.ignite.ScrapyIgniteException: IGNITE EXCEPTION :: Exception while scanning for keys with given pattern in Ignite db - DOCIDS. Exception - IDSCaused by: javax.cache.CacheException: class org.apache.ignite.IgniteCheckedException: Failed to execute query on node [query=GridCacheQueryBean [qry=GridCacheQueryAdapter [type=SCAN, clsName=null, clause=null, filter=com.xyz.scrapy.common.ignite.IgniteQuery$QueryObject$$Lambda$243/2029270129@58665d95, transform=null, part=null, incMeta=false, pageSize=1024, timeout=0, incBackups=false, forceLocal=false, dedup=false, prj=org.apache.ignite.internal.cluster.ClusterGroupAdapter@1dfc48e7, keepBinary=false, subjId=0ef0942f-d2d1-4ac0-aa5b-783b3e1a0960, taskHash=0, mvccSnapshot=null, dataPageScanEnabled=null], rdc=null, trans=null], nodeId=f01b04de-66c0-4edc-8efe-4977ecf656b1]
at org.apache.ignite.internal.processors.cache.GridCacheUtils.convertToCacheException(GridCacheUtils.java:1272)
at org.apache.ignite.internal.processors.cache.query.GridCacheQueryFutureAdapter.next(GridCacheQueryFutureAdapter.java:167)
at org.apache.ignite.internal.processors.cache.query.GridCacheDistributedQueryManager$5.onHasNext(GridCacheDistributedQueryManager.java:645)
at org.apache.ignite.internal.util.GridCloseableIteratorAdapter.hasNextX(GridCloseableIteratorAdapter.java:52)
at org.apache.ignite.internal.util.lang.GridIteratorAdapter.hasNext(GridIteratorAdapter.java:44)
at org.apache.ignite.internal.processors.cache.AutoClosableCursorIterator.hasNext(AutoClosableCursorIterator.java:47)
at com.xyz.scrapy.common.ignite.IgniteQuery$QueryObject.scan(IgniteQuery.java:103)
at com.xyz.scrapy.common.ignite.IgniteQuery.executeFieldsQuery(IgniteQuery.java:47)
at com.xyz.scrapy.common.ignite.IgniteConnectionHandler$CacheHolder.scanKeys(IgniteConnectionHandler.java:302)
Caused by: class org.apache.ignite.binary.BinaryInvalidTypeException: com.xyz.scrapy.common.ignite.IgniteObject
at org.apache.ignite.internal.binary.BinaryContext.descriptorForTypeId(BinaryContext.java:643)
at org.apache.ignite.internal.binary.BinaryReaderExImpl.deserialize0(BinaryReaderExImpl.java:1755)
at org.apache.ignite.internal.binary.BinaryReaderExImpl.deserialize(BinaryReaderExImpl.java:1714)
at org.apache.ignite.internal.processors.cache.CacheObjectUtils.unwrapBinary(CacheObjectUtils.java:177)
at org.apache.ignite.internal.processors.cache.CacheObjectUtils.unwrapBinaryIfNeeded(CacheObjectUtils.java:40)
at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager$ScanQueryIterator.advance(GridCacheQueryManager.java:3050)
at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager$ScanQueryIterator.onHasNext(GridCacheQueryManager.java:2952)
at org.apache.ignite.internal.util.GridCloseableIteratorAdapter.hasNextX(GridCloseableIteratorAdapter.java:52)
at org.apache.ignite.internal.util.lang.GridIteratorAdapter.hasNext(GridIteratorAdapter.java:44)
at org.apache.ignite.internal.processors.cache.query.GridCacheQueryManager.runQuery(GridCacheQueryManager.java:1141)
at org.apache.ignite.internal.processors.cache.query.GridCacheDistributedQueryManager.processQueryRequest(GridCacheDistributedQueryManager.java:232)
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:1142)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.onMessage0(GridCacheIoManager.java:591)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.handleMessage(GridCacheIoManager.java:392)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.handleMessage(GridCacheIoManager.java:318)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager.access$100(GridCacheIoManager.java:109)
at org.apache.ignite.internal.processors.cache.GridCacheIoManager$1.onMessage(GridCacheIoManager.java:308)
at org.apache.ignite.internal.managers.communication.GridIoManager.invokeListener(GridIoManager.java:1635)
at org.apache.ignite.internal.managers.communication.GridIoManager.processRegularMessage0(GridIoManager.java:1255)
at org.apache.ignite.internal.managers.communication.GridIoManager.access$4300(GridIoManager.java:144)
at org.apache.ignite.internal.managers.communication.GridIoManager$8.execute(GridIoManager.java:1144)
Caused by: java.lang.ClassNotFoundException: com.xyz.scrapy.common.ignite.IgniteObject
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
有人可以解释为什么Ignite从缓存DOCIDS获取IgniteObject吗？因为我只将IgniteObject存储在“ URLS”缓存中，而不存储在“ DOCIDS”中。实际的例外是它没有加载IgniteObject类。我什至不知道为什么它不能加载，因为我可以插入那些对象而没有任何问题。
IgniteObject类如下
import org.apache.ignite.binary.BinaryObject;
import org.apache.ignite.binary.BinaryObjectBuilder;
import java.io.Serializable;
//If value is not String, every value of K-V Store should wrap its contents with this Object
public class IgniteObject implements Serializable {
//Value set via Reflection
private Object object;
public static BinaryObject convertToBinaryObject(Object object) throws Exception{
//IgniteConnectionHandler.getConnection() will get Ignite Object named ignite. getObjectBuilder will do ignite.binary().builder(stringValue)
BinaryObjectBuilder builder = IgniteConnectionHandler.getConnection().getObjectBuilder(IgniteObject.class.getName());
builder.setField("object", object);//No I18N
return builder.build();
}
public Object getActualObject(){
return object;
}
}
注意：cacheHolder.getSecondaryCache（）将提供对象-IgniteCache。
最佳答案
即使仅使用密钥，也会在Cache.Entry中同时获得密钥和值，这很容易发生。
你可以试试
cacheHolder.getSecondaryCache().withKeepBinary().query(...)
避免需要
IgniteObject类。