In ireportDesigner 5.6.0, I am adding an image from database. When I add that image,in xml it is shown as java.lang.Object and I have changed it to java.a
With additional info that you added this is what I would do:
The correct field class should be java.sql.Blob (corrispond to the database mapping)
The image expression should be (On the Blob we call the getBinaryStream() that gives us a java.io.InputStream)
To improve code some it would be great to check that $F{companyLogo}!=null,
a small note... why not pass it as parameter, hence load it in your java and pass it as a java.io.InputStream or java.io.Image... this way maybe also your jasper gets cleaner...