A user defined object (UDO) is an object inherited from JReport system's object. You can add and modify new properties, as well as other existing methods and specify new methods for modifying your UDO. In JReport Designer, UDOs, which have been appended to the class path variable of JReport.bat in <install_root>\bin, can be inserted into reports as if they are regular JReport objects. Thus, UDOs become part of the report created by JReport Designer.
Go through the following topics for details about UDOs: