invalid stream header during java byte deserialization from sql server

Question

I need to save in SQL Server 2008 table a serialized Object Stream and then deserialize it. The problem arise when i deserialize..I get the following Exception:

Exception in thread "main" java.io.StreamCorruptedException: invalid stream header: 5B424065
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:804)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:299)

I use JTDS-1.2.4 (not the last JTDS Driver Type 4)

In table i save in a column type -> NVARCHAR(MAX), i have this value for e.g.

[B@e3fd79

i read the value above (jtds give me a sql.Clob) and i try to deserialize it

My Java Code:

    DocumentObjectHolder doc = new DocumentObjectHolder(xmldata, "data.xml", TYPE.XML, xmldata.getBytes("UTF-8"));
//SERIALIZE DocumentObjectHolder 
            ByteArrayOutputStream bof = new ByteArrayOutputStream();
            ObjectOutputStream serialize = new ObjectOutputStream(bof);
            serialize.writeObject(doc);
            SQLDbManagerFactory.setDbConnectionParameters(dbUri, username, password, driver);
            SQLDBManager factoryDb = SQLDbManagerFactory.getSQLDBManager();

            factoryDb.execSQL("INSERT INTO MY_DOCUMENTS (DATA,DOCUMENT_TYPE,IS_READY,DO_EMIT,IS_EMITTED)" + 
            " VALUES ( '" + bof.toByteArray() + "','" + TYPE.XML.name() + "', 0, 0, 0)");

            RecordSet rs = (RecordSet) factoryDb.execSQL("SELECT TOP 1 DATA FROM MY_DOCUMENTS");
            if (rs != null && rs.getLength() > 0){
//DESERIALIZE in DocumentObjectHolder 
                Clob objris = (Clob)rs.get(0, 0);  
                InputStream in = objris.getAsciiStream();
                byte[] b = new byte[in.available()];
                in.read(b);
                ByteArrayInputStream bais = new ByteArrayInputStream(b);
                ObjectInputStream ins = new ObjectInputStream(bais);
                DocumentObjectHolder mc =(DocumentObjectHolder)ins.readObject();
                System.out.println("Object in value ::"+mc.toString());
                ins.close();
                in.close();
            }

SQLDBManager is my private library ..

I suppose it would be a Blob (byte blob) not a Clob (char lob), so i tried to change nvarchar(max) to varbinary(500) because i read here: http://jtds.sourceforge.net/typemap.html

but i get the following exception:

Exception in thread "main" java.sql.SQLException: Invalid SQL statement or JDBC escape, terminating ']' not found.
at net.sourceforge.jtds.jdbc.SQLParser.parse(SQLParser.java:1155)
at net.sourceforge.jtds.jdbc.SQLParser.parse(SQLParser.java:156)
at net.sourceforge.jtds.jdbc.JtdsPreparedStatement.<init>(JtdsPreparedStatement.java:107)
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.prepareStatement(ConnectionJDBC2.java:2456)
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.prepareStatement(ConnectionJDBC2.java:2414)

What's wrong?

Stephen C · Answer 1 · 2015-05-06T13:19:56.467

Lets start with the "header" 5B424065.

If you translate that as ASCII, you get '[' 'B' '@' 'e' ... Does that look familiar?

Now your the string "[B@e3fd79". What is it?

First of all, it is NOT a valid serialization. In fact, what it is ... is what you get when you call toString() on an byte[].

The "[B" component is the type signature for a byte[].
The "e3fd79" component is an identity hash code ... which is typically based on the arrays address, at the time that the identity hash code was first requested.
Most important, this string does not encode the byte array's contents/

So where is it coming from?

It comes from this expression: bof.toByteArray(). That is not the right way to turn the contents of the byte array into a string.

What is the right way?

It depends on the SQL type of the "DATA" column. And yes - @EJP is spot on. You should not be trying to stringify the byte array at all. Use a PreparedStatement an a parameter placeholder (?).

If the column type is BINARY or VARBINARY, then you should be able to pass the byte[] as-is. For a full listing for the type mappings of jDTS, refer to the documentation.

DATA was nvarchar(max) then i changed to varbinary and then i tried binary but i get the same DataTruncated Ex.. So it's wrong using toByteArray() because it write the String byte or is wrong sql data type? — robyp7, May 05 '15 at 16:06
maybe i have to use string instead of byte like in this post? -> http://stackoverflow.com/questions/134492/how-to-serialize-an-object-into-a-string — robyp7, May 05 '15 at 19:29
@robyp7 You shouldn't be turning the byte array into a string at all. You should be using `PreparedStatement` with a ? marker. — user207421, May 05 '15 at 22:50

invalid stream header during java byte deserialization from sql server

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