开发者

How to extract an XML document from a BLOB column in Oracle thats been compressed in Java

开发者 https://www.devze.com 2023-04-09 02:54 出处:网络
I have a table in Oracle 11G (11.1) that has a BLOB column containing XML documents. The XML document has been written to the table using a java program and has been serialised and compressed using j

I have a table in Oracle 11G (11.1) that has a BLOB column containing XML documents.

The XML document has been written to the table using a java program and has been serialised and compressed using java.util.zip deflator.

Is there a simple way to extract this document using SQL or PLSQL to reverse the process used to create the BLOB column to get back the original XML document ?

I identified a piece of java from a web application that reads the column that looks like the code below but for support purposes, would like to be able to access the column data from the back end.

private IntegrationStagingDataBean fromObjectToBean(StagedMessage message) throws ServerException {
    IntegrationStagingDataBean bean = new IntegrationStagingDataBean();
    bean.setBusinessId(message.getBusinessId());
    bean.setBusinessType(message.getBusinessType());
    bean.setCreateTime(message.getCreateTime());
    bean.setDeleted(message.hasBeenDeleted() ? "Y" : "N");
    bean.setErrorMessage(message.getErrorMessage());
    bean.setId(message.getId());
    bean.setStoreId(message.getStoreId());
    bean.setMessageDirection(message.getMessageDirection().getDbCode());
    bean.setMessageFamily(message.getMessageFamily().getDbCode());
    bean.setMessageType(message.getMessageType().getDbCode());
    bean.setProcessed(message.hasBeenProcessed() ? "Y" : "N");
    bean.setRetryCount(message.getRetryCount());
    bean.setUpdateTime(message.getUpdateTime());
    try {
        bean.setSerializedDeo(ObjectUtils.toByteArray(new CompressedObject(message.getDeo())));
    } catch (IOException ioex) {
        throw new ServerException("Problem setting compressed serialized object", ioex);
    }
    return bean;
}

private StagedMessage fromBeanToObject(IntegrationStagingDataBean bean) throws ServerException {
    DataExchangeObject deo = null;
    Blob blob = (Blob) bean.getSerializedDeo();
    try {
        CompressedObject compressedObject = (CompressedObject) new              
              ObjectInputStream(blob.getBinaryStream()).readObject();
        deo = (DataExchangeObject) compressedObject.recoverObject();
    } catch (Exception e) {
        throw new ServerException("Couldn't uncompress/deserialize DEO from BLOB", e);
    }

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

and found the following additional functions spread across a handful of packages which indicate it is using the java function deflater from java.util.zip.*;

public CompressedObject(Object object) throws IOException { dataToSend = null; if(object != null) dataToSend = ObjectUtils.toCompressedByteArray(object); }

public static final byte[] toCompressedByteArray(Object o)
    throws IOException
{
    return compressByteArray(toByteArray(o));
}

public static final byte[] compressByteArray(byte input[])
{
    Deflater compressor = new Deflater(9);
    compressor.setInput(input);
    compressor.finish();
    ByteArrayOutputStream bos = new ByteArrayOutputStream(input.length);
    byte buf[] = new byte[1024];
    int count;
    for(; !compressor.finished(); bos.write(buf, 0, count))
        count = compressor.deflate(buf);

    try
    {
        bos.close();
    }
    catch(IOException e) { }
    return bos.toByteArray();
}

public static final byte[] decompressByteArray(byte arr[])
{
    Inflater decompressor = new Inflat开发者_运维百科er();
    decompressor.setInput(arr);
    ByteArrayOutputStream bos = new ByteArrayOutputStream(arr.length);
    byte buf[] = new byte[1024];
    while(!decompressor.finished()) 
        try
        {
            int count = decompressor.inflate(buf);
            bos.write(buf, 0, count);
        }
        catch(DataFormatException e) { }
    try
    {
        bos.close();
    }
    catch(IOException e) { }
    return bos.toByteArray();
}

Thanks in advance.

0

精彩评论

暂无评论...
验证码 换一张
取 消

关注公众号