在Oracle Blob中保留Java对象

Question

我有一个小问题，可能您可以帮忙。 我想要做的是将任何给定的Java对象（可序列化）持久化到数据库的blob字段中。

目标：在Oracle Blob中保留Java对象

方式：序列化对象并创建一个BlobDomain作为实体的一部分，映射到数据库中的BLOB字段

编码：

实体：

@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;

...
}

设置值：

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();
}

错误： Argument实体在数据库（ARGUMENT表）中正确放置，但是当我尝试查询表的任何行时，它引发以下异常：

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

有谁知道，为什么会这样？

提前致谢！！

全栈：

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

您需要添加注释

@Lob


import javax.persistence.Lob;

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

如果对象很大，也可以定义列的长度。

@Column(length = 20971520)

@Lob ，指定应将持久性属性或字段作为大对象持久化为数据库支持的大对象类型。