Allow custom annotation only one one method per class

Question

I have a annotation @ToolExecution. At the moment I use annotation processing and throwing Error to ensure that only one method is annotated with this annotation.

Is there an native way to create a constraint and allow my custom annotation to be only applied to one annotation per class?

This should not be possible

@Tool(id = "scheduledtool")
public class ScheduledTool extends SimpleTool {
  private String parameter;

  @ToolExecution
  public void configuration(@ToolParameters(fields = {"config"}, credentials = true) ToolParameter parameters) {
    String parameter = parameters.getParameter("config");
    this.parameter = parameter;
  }

  @ToolExecution
  public void execute() {
    toolLog(Level.INFO, "Configured Param: " + parameter);
    toolLog(Level.INFO, "Finished scheduled tool");
  }

}

You can't enforce a single method annotation per class at compile time, you can only do that type of validation at runtime. — lance-java, Feb 21 '18 at 22:42
You should learn [Annotation Processor](https://medium.com/@iammert/annotation-processing-dont-repeat-yourself-generate-your-code-8425e60c6657) — Dean Xu, Feb 22 '18 at 00:46

score 0 · Answer 1 · answered Feb 21 '18 at 22:36

0

You can't enforce a single method annotation per class at compile time, you can only do that type of validation at runtime.

answered Feb 21 '18 at 22:36

lance-java

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Allow custom annotation only one one method per class

This should not be possible

1 Answers1