Here is an example:
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NOTE:
Java does not currently support pasting objects like images from external applications. You could copy an ImageIcon and treat it as a javaSerializedObjectMimeType. However, it would then only be pasteable into another Java program, or a program that understands Java's serialization mechanism, which will be described in the "Object Persistence and Serialization" section of Chapter 19.
From:
http://developer.java.sun.com/developer/Books/MasteringJava/Ch16/index.html