Re: Create java.sql.Blob from byte[]

From: Sebastian Scheid (mynewsgroup_at_web.de)
Date: 10/16/04

  • Next message: Ken Philips: "Difference between Statement and preparedStatement (for SQL databases) ?" 
    Date: Sat, 16 Oct 2004 12:12:43 +0200

    "Shay" <shayn@idit.co.il> schrieb im Newsbeitrag
    news:b2d1425c.0410140630.94e0b2@posting.google.com...
    > Hello All
    >
    > How can I create Blob from byte array?
    > I use jdk1.3.1_06.
    > I think that I must create a new class implements the Blob interface
    > but I'm not sure.

    I found this in comp.databases.ibm-db2:

    HOW TO INSERT A BLOB IN A DB USING JAVA

    "normal" JDBC
    -------------
    1.) byte []

    byte [] data = ...
    String query = "UPDATE tableWithBlob SET blobAtt = ? WHERE idAtt = " +
    id ;
    PreparedStatement pstmt = connection.prepareStatement(query);
    pstmt.setBinaryStream(1,new ByteArrayInputStream(data),data.length);
    pstmt.execute();
    pstmt.close();

    2.) Object

    Object data = ... (Serializable)
    String query = "UPDATE tableWithBlob SET blobAtt = ? WHERE idAtt = " +
    id ;
    PreparedStatement pstmt = connection.prepareStatement(query);

    ByteArrayOutputStream b = new ByteArrayOutputStream();
    ObjectOutputStream out = new ObjectOutputStream(b);
    out.writeObject(data);
    byte [] dataAsByteArray = b.toByteArray();
    pstmt.setBinaryStream(1,new
    ByteArrayInputStream(dataAsByteArray),dataAsByteArray.length);
    pstmt.execute();
    pstmt.close();

    Instead of
      pstmt.setBinaryStream(1,new
    ByteArrayInputStream(dataAsByteArray),dataAsByteArray.length);
    you can use
      pstmt.setBytes(1, dataAsByteArray);
    but this method seems to have a limit of 33124 bytes!

    Proptietary solution for Oracle: oracle.sql.BLOB needed
    -------------------------------------------------------

    1.) byte []

    byte [] data = ...
    Statement stmt = connection.createStatement();
    String query = "SELECT blobAtt FROM tableWithBlob WHERE idAtt = " + id +
    " FOR UPDATE";
    ResultSet rs = stmt.executeQuery(query);
    rs.next();
    oracle.sql.BLOB blob = (BLOB)rs.getBlob("id");

    OutputStream outstream = blob.getBinaryOutputStream();
    outstream.write(data);
    outstream.flush();
    outstream.close();

    2.) Object

    Object data = ... (Serializable)
    BLOB blob = find the blob like above;

    OutputStream outstream = blob.getBinaryOutputStream(); //to write the
    blob
    ObjectOutputStream out = new ObjectOutputStream(outstream); //to
    serialize the object
    out.writeObject(data);
    out.flush();
    out.close();

  • Next message: Ken Philips: "Difference between Statement and preparedStatement (for SQL databases) ?"