Difficulty setting ArrayList to java.sql.Blob to save in DB using hibernate
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Published on 2010-06-10T11:43:08Z
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2010/06/10
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I'm trying to save a java ArrayList in a database (H2) by setting it as a blob, for retrieval later. If this is a bad approach, please say - I haven't been able to find much information on this area.
I have a column of type Blob in the database, and Hibernate maps to this with java.sql.Blob. The code I'm struggling with is:
Drawings drawing = new Drawings();
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = null;
oos = new ObjectOutputStream(bos);
oos.writeObject(plan.drawingPane21.pointList);
byte[] buff = bos.toByteArray();
Blob drawingBlob = null;
drawingBlob.setBytes(0, buff);
drawing.setDrawingObject(drawingBlob);
} catch (Exception e){
System.err.println(e);
}
The object I'm trying to save into a blob (plan.drawingPane21.pointList) is of type ArrayList<DrawingDot>, DrawingDot being a custom class implementing Serializable.
My code is failing on the line drawingBlob.setBytes(0, buff); with a NullPointerException.
Help appreciated.
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