How To Fix OL721 - The object type already supports the method '&1' from another interface

SAP Error Message - Details

• Message type: E = Error

• Message class: OL - Workflow object types: Run-time system

• Message number: 721

• Message text: The object type already supports the method '&1' from another interface

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message OL721 - The object type already supports the method '&1' from another interface ?

  The SAP error message OL721 indicates that there is a conflict in the implementation of methods in an ABAP class or interface. Specifically, it means that the object type (class) you are trying to implement already has a method with the same name as the one you are trying to implement from another interface. This typically occurs when a class implements multiple interfaces that define methods with the same name.
  Cause:
  
  Multiple Interface Implementations: The class is implementing two or more interfaces that have a method with the same name.
  Inheritance Conflicts: If the class inherits from a superclass that already implements the method, and you are trying to implement it again from an interface.
  Method Signature Mismatch: If the method signatures (parameters, return types) do not match exactly, it can lead to confusion in implementation.
  
  Solution:
  
  Check Interface Definitions: Review the interfaces that the class is implementing. Identify the methods that have the same name and determine if they can be unified or if one can be removed.
  Use Unique Method Names: If possible, rename the method in one of the interfaces to avoid the conflict.
  Implement Only Once: If the method is already implemented in a superclass or another interface, you do not need to implement it again in the class.
  Adjust Method Signatures: Ensure that the method signatures are consistent across the interfaces and the class. If they differ, you may need to adjust them to match.
  Refactor Code: If the design allows, consider refactoring the code to avoid such conflicts, possibly by using composition instead of inheritance.
  
  Related Information:
  
  ABAP Documentation: Review the official SAP documentation on ABAP classes and interfaces for best practices on method implementation.
  SAP Community: Engage with the SAP community forums for insights and similar experiences from other developers.
  Debugging Tools: Use the ABAP debugger to trace where the method is being called and how it is being resolved in the class hierarchy.
  
  By following these steps, you should be able to resolve the OL721 error and ensure that your class implementations are clear and conflict-free.