Programming and So

Sometimes, inside of a java method, it’s needed to know which is the invoking method. I don’t know any documented procedure/technique to provide this information. So I use to develop a low performance piece of code based on an exception throwing and catching.

public void mockMethod() {
    // Invoking Class
    String invokingClass = "";
    String invokingMethod = "";
   
    // Where I come from?
    try {
      throw new Exception();
    } catch (Exception e) {
   
      // StackTrace to String
      StringWriter sw = new StringWriter();
      e.printStackTrace(new PrintWriter(sw));

      // Split lines using "at " substring as separator
      // Invoker is located at position 2 of the array
      String[] lines = sw.toString().split("at ");

      // a dot followed by a capital letter (ex. package.Class)
      boolean dotCapital = false;
      // find dotCapital position
      int i = 0;
      while (!dotCapital) {
        dotCapital =
            lines[2].charAt(i) == '.' &&
            Character.isUpperCase(lines[2].charAt(i + 1));
        i++;
      }
     
      // Class substring
      while(!(lines[2].charAt(i) == '.')) {
        invokingClass = invokingClass + lines[2].charAt(i);
        i++;
      }
      i++;
     
      // Method substring
      while(!(lines[2].charAt(i) == '(')) {
        invokingMethod = invokingMethod + lines[2].charAt(i);
        i++;
      }
     
    }
    System.out.println("Invoking class: " + invokingClass + "." + invokingMethod);
  }

Inelegant but effective.