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. UDOs, which have been appended to the ADDCLASSPATH variable of setenv.bat in <install_root>\bin, can be inserted as components into a report and consequently become a part of the report.
Go through the following topics for details about UDOs: