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Thread: [Asking] Store method in HashMap

  1. #1
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    Default [Asking] Store method in HashMap

    Hi everyone,

    I got trouble about storing method in HashMap. I got the example but there is no parameter in method, You can see the code below

    import java.lang.reflect.InvocationTargetException;
    import java.lang.reflect.Method;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.logging.Level;
    import java.util.logging.Logger;
     
    /**
     *
     * @author user
     */
    public class PracticeMap {
        public static void main(String[] args) {
             Map<String, Method> methodMap = new HashMap<String, Method>();
            try {
                methodMap.put("help", PracticeMap.class.getMethod("showHelp"));
                methodMap.get("help").invoke(null);
     
            } catch (NoSuchMethodException ex) {
                Logger.getLogger(PracticeMap.class.getName()).log(Level.SEVERE, null, ex);
            } catch (SecurityException ex) {
                Logger.getLogger(PracticeMap.class.getName()).log(Level.SEVERE, null, ex);
            }catch (IllegalAccessException ex) {
                Logger.getLogger(PracticeMap.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IllegalArgumentException ex) {
                Logger.getLogger(PracticeMap.class.getName()).log(Level.SEVERE, null, ex);
            } catch (InvocationTargetException ex) {
                Logger.getLogger(PracticeMap.class.getName()).log(Level.SEVERE, null, ex);
            }
     
        }
     
        public static void showHelp() {
            System.out.println("Help me!!");
        }
    }

    I want to put parameter in showHelp method. But I don't how to that.

    Please share me information if you already know


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: [Asking] Store method in HashMap

    Are you trying to use the reflection classes and methods to call a method in an object?

    What happens when the code is execute?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: [Asking] Store method in HashMap

    Hi norm,
    Yes, I use it
    The code will print Help me!!
    But it's difficult to use param on showHelp method. Please tell me if i did mistake on explanation

  4. #4
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    Default Re: [Asking] Store method in HashMap

    Can you explain what mistake you think you made?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: [Asking] Store method in HashMap

    Hi Norm,
    Do you know about reflection in java ? I little don't understand about that.

  6. #6
    Super Moderator Norm's Avatar
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    Default Re: [Asking] Store method in HashMap

    One place to get info would be to read the API doc for the classes in the java.lang.reflect package.

    See the tutorial: http://docs.oracle.com/javase/tutori...ect/index.html
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: [Asking] Store method in HashMap

    Thank you Norm,

    Finally I got it

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