Java IOException:流已关闭Hibernate MS SQL JDBC4

在获取二进制流时，我收到以下异常

    java.io.IOException: The stream is closed.
at com.microsoft.sqlserver.jdbc.BaseInputStream.checkClosed(SimpleInputStream.java:93)
at com.microsoft.sqlserver.jdbc.PLPInputStream.read(PLPInputStream.java:237)
at au.gov.vic.doi.tp.service.binary.dao.BinaryDAOImplTest.retrieveBinary(BinaryDAOImplTest.java:102)

我使用的是：Hibernate 4.1.1、MS SQL Server 2008和最新的MS SQL JDBC4驱动程序。 我使用以下自定义映射类型“BlobToStreamUserType”将SQL Blob varcharmax映射到InputStream。Hibernate似乎没有提供将SQL BLOB映射到Java InputStream的类型，MaterializedBlob类型仅将SQL BLOB映射到Java字节[]

我使用'rs.getBinaryStream'返回一个真正的二进制流，而不是内存中缓冲的流，原因是我们有大量的图像，如果多个用户同时访问，将导致内存问题

据微软称

Microsoft驱动程序遵循关于getBinaryStream=>JDBC规范 注意：在获取任何>其他列的值之前，必须读取返回流中的所有数据。对getter方法的下一次调用隐式关闭流。此外，当调用方法InputStream.available时，无论是否有数据>可用，stream>都可能返回0

因此getBinaryStream被设计为返回一个真正的字节流。我们返回一个未在内存中缓冲的真正字节流>，它是一个从服务器响应中直接读取的流>。在获取实现的所有>字节之前，无法关闭contentDataResultSet

我已经尝试将hibernate属性“hibernate.jdbc.use_streams_for_binary”设置为true和false，但是这没有什么区别

这是我的密码：

显示到自定义用户类型的映射的图像实体类

   import java.io.InputStream;
   import java.util.Date;
   import javax.persistence.Column;
   import javax.persistence.Entity;
   import javax.persistence.GeneratedValue;
   import javax.persistence.Id;
   import javax.persistence.Table;
   import org.hibernate.annotations.DynamicInsert;
   import org.hibernate.annotations.DynamicUpdate;
   import org.hibernate.annotations.GenericGenerator;
   import org.hibernate.annotations.Type;
   import com.google.common.base.Objects;

   @Entity
   @DynamicInsert(false)
   @DynamicUpdate(false)
   @Table(name = "Binary")
   public class Binary
   {
   .........
    @Lob
    @Column(name = "image")
    @Type(type = "my.package.BlobToStreamUserType")   
    public InputStream getImageStream()
    {
        return this.imageStream;
    }
    }

以下是我的自定义映射类型：

public class BlobToStreamUserType implements UserType
{

public int[] sqlTypes()
{
    return new int[]
    { Types.BLOB };
}

public Class returnedClass()
{
    return InputStream.class;
}

public Object nullSafeGet(final ResultSet rs, final String[] names, final SessionImplementor session,
        final Object owner) throws HibernateException, SQLException
{
    return rs.getBinaryStream(names[0]);
}

public void nullSafeSet(final PreparedStatement st, final Object value, final int index,
        final SessionImplementor session) throws HibernateException, SQLException
{

    if (value != null)
    {
        if (!InputStream.class.isAssignableFrom(value.getClass()))
        {
            throw new HibernateException(value.getClass().toString() + " cannot be cast to a java.IO.InputStream");
        }
        InputStream inStream = (InputStream) value;
        st.setBinaryStream(index, inStream);
    }
    else
    {
        st.setBytes(index, null);
    }
}

public boolean equals(final Object x, final Object y) throws HibernateException
{
    return ObjectUtils.equals(x, y);
}

public int hashCode(final Object x) throws HibernateException
{
    assert (x != null);
    return x.hashCode();
}

public Object deepCopy(final Object value) throws HibernateException
{
    return value;
}

public boolean isMutable()
{
    return false;
}

public Object replace(final Object original, final Object target, final Object owner) throws HibernateException
{
    return original;
}

public Serializable disassemble(final Object value) throws HibernateException
{
    //disassemble() is only called when caching the data in the second-level cache
    // also safe for mutable objects
    throw new UnsupportedOperationException("Not supported yet.");
}

public Object assemble(final Serializable cached, final Object owner) throws HibernateException
{
    throw new UnsupportedOperationException("Not supported yet.");
}

}

这是我用来检索图像流的DAO

public class BinaryDAOImpl extends AbstractSpringHibernateDAO implements BinaryDAO
{

public Binary getBinary(final String amsAssetId, final String assetMaintainer, final String variant,
        final Integer sequence) throws GetException
{

    try
    {
        Query query = super.getSession().createQuery(
                "from Binary bin where bin.amsAssetId = :amsAssetId and bin.assetMaintainer = :assetMaintainer "
                        + "and bin.variant = :variant and bin.sequence = :sequence");
        query.setParameter("amsAssetId", amsAssetId);
        query.setParameter("assetMaintainer", assetMaintainer);
        query.setParameter("variant", variant);
        query.setParameter("sequence", sequence);
        return query.uniqueResult();
    }

注意：以下绕过hibernate并直接从结果集中检索流的解决方法可以工作，并且允许我毫无例外地读取流。然而，我宁愿使用hibernate映射来检索真正的二进制流

改进的DAO方法

public Binary getBinary(final String amsAssetId, final String assetMaintainer, final String variant,
        final Integer sequence) throws GetException
{
    try
    {
        Query query = super.getSession().createQuery(
                "from Binary bin where bin.amsAssetId = :amsAssetId and bin.assetMaintainer = :assetMaintainer "
                        + "and bin.variant = :variant and bin.sequence = :sequence");
        query.setParameter("amsAssetId", amsAssetId);
        query.setParameter("assetMaintainer", assetMaintainer);
        query.setParameter("variant", variant);
        query.setParameter("sequence", sequence);
        Binary binary = (Binary) query.uniqueResult();

        final String id = binary.getId();

        // Necessary until Hibernate supports InputStream mapping
        binary.setImageStream(getSession().doReturningWork(new ReturningWork<InputStream>()
        {
                      public InputStream execute(final Connection connection) throws SQLException
                        {
                            PreparedStatement statement = connection.prepareStatement("select image from Binary where id=?",
                                    ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);

                            statement.setString(1, id);

                            ResultSet resultSet = statement.executeQuery();

                            return (resultSet.first() ? resultSet.getBinaryStream(1) : null);
                        }
                    }));

        return binary;

    }

---

您是否尝试过将该类型标记为Lob

@Lob
@Column(name = "image")
@Type(type = "my.package.BlobToStreamUserType")   
Blob blob;

public Blob getBlob(){
   return blob;
} 

什么时候你需要使用流

            final InputStream is;
    try {
        is = blob.getBinaryStream();
                    //do some work
            }

如果你知道你可以简单地找回一个斑点，那会很有帮助 在定义自己的类型之前