在Oracle Blob中保留Java對象

Question

我有一個小問題，可能您可以幫忙。 我想要做的是將任何給定的Java對象（可序列化）持久化到數據庫的blob字段中。

目標：在Oracle Blob中保留Java對象

方式：序列化對象並創建一個BlobDomain作為實體的一部分，映射到數據庫中的BLOB字段

編碼：

實體：

@Entity
@Table(name = "ARGUMENT")
public class Argument implements java.io.Serializable {
    private static final long   serialVersionUID    = 1L;

    @Id @Column(name = "ID")
    private Long                id;

    @Column(name = "B_VALUE")
    private BlobDomain          value;

...
}

設置值：

private void createArgument (Serializable argVal) throws RuntimeException {
    // argVal is the object to be stored
    Argument arg = new Argument();
    byte[] bytes = serialize(argVal);
    BlobDomain value = new BlobDomain(bytes);
    arg.setValue(value);
    argumentDao.persist(arg);
}

public byte[] serialize(Object obj) throws IOException, SerialException, SQLException {
    ByteArrayOutputStream bs = new ByteArrayOutputStream();
    ObjectOutputStream os = new ObjectOutputStream(bs);
    os.writeObject(obj);
    os.close();
    return bs.toByteArray();
}

錯誤： Argument實體在數據庫（ARGUMENT表）中正確放置，但是當我嘗試查詢表的任何行時，它引發以下異常：

org.hibernate.type.SerializationException：無法反序列化

有誰知道，為什么會這樣？

提前致謝！！

全棧：

org.hibernate.type.SerializationException: could not deserialize
    at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:188)
    at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:211)
    at org.hibernate.type.SerializableType.fromBytes(SerializableType.java:105)
    at org.hibernate.type.SerializableType.get(SerializableType.java:62)
    at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:184)
    at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:173)
    at org.hibernate.type.AbstractType.hydrate(AbstractType.java:105)
    at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2124)
    at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1404)
    at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1332)
    at org.hibernate.loader.Loader.getRow(Loader.java:1230)
    at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:603)
    at org.hibernate.loader.Loader.doQuery(Loader.java:724)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    at org.hibernate.loader.Loader.loadCollection(Loader.java:2015)
    at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:59)
    at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:587)
    at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83)
    at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1743)
    at org.hibernate.collection.AbstractPersistentCollection.forceInitialization(AbstractPersistentCollection.java:476)
    at org.hibernate.engine.StatefulPersistenceContext.initializeNonLazyCollections(StatefulPersistenceContext.java:867)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:264)
    at org.hibernate.loader.Loader.doList(Loader.java:2228)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
    at org.hibernate.loader.Loader.list(Loader.java:2120)
    at org.hibernate.hql.classic.QueryTranslatorImpl.list(QueryTranslatorImpl.java:935)
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
    at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:67)
    ... 38 more
Caused by: java.io.StreamCorruptedException: invalid stream header
    at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:764)
    at java.io.ObjectInputStream.<init>(ObjectInputStream.java:277)
    at org.hibernate.util.SerializationHelper$CustomObjectInputStream.<init>(SerializationHelper.java:223)
    at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:180)
    ... 67 more

Answer 1

您需要添加注釋

@Lob


import javax.persistence.Lob;

@Column(name = "B_VALUE")
@Lob
private BlobDomain          value;

如果對象很大，也可以定義列的長度。

@Column(length = 20971520)

@Lob ，指定應將持久性屬性或字段作為大對象持久化為數據庫支持的大對象類型。