Question

I have been trying to set up a program that sends a push notification for my app. First I used
this tutorial
http://mobiforge.com/developing/story/programming-apple-push-notification-services

From this I learned how to get my device’s token.
I tried following the rest of to tutorial, but got stuck near the end, which told me to download a class named PushMeBaby, and change some lines of code and run it. However I can’t even compile this application. It gives me the error:

The run destination My Mac 64-bit is not valid for Running the scheme ‘PushMeBaby’.

after many hours of trying to figure this out, I decided to switch to a new tutorial, because i couldn’t find a way to fix this one.

This lead me to java and a certain java class named JavaApns
http://code.google.com/p/javapns/

Inorder to install this library and to get it to work, you need to meet a few requirements
Here is where I think the problem arises. The 3rd requirement tells me to also download and install two other libraries :

bcprov-jdk15-146.jar
log4j-1.2.15.jar

The first library works fine, since there is no errors. However log4 comes in a zipped file, and whenever I try to unzip it, it gives me the error “An unexpected error occurred (28)” So I just go into the zip file and only unzip the library instead of the whole file (no errors). Then I put both libraries+JavaAPNS into my project and run it with

[my code]

import javapns.Push;
import javapns.communication.exceptions.CommunicationException;
import javapns.communication.exceptions.KeystoreException;


public class test {
    public static void main(String[] args) {

    try {
        Push.alert("Hello World!", "MyCertificate.p12", "MyPassword",false, "MyDevicetoken");
    } catch (CommunicationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (KeystoreException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


       }
}

Finally the error that this gives me is:
/////////////////////////////////////////////////////////////////////////////////

log4j:WARN No appenders could be found for logger (javapns.notification.Payload).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

/////////////////////////////////////////////////////////////////////////////////

I went to the link logging.apache.org/log4j/1.2/faq.html#noconfig, however it doesn’t really explain how to solve the problem. So if you have any ideas or suggestions ( Or you want to suggest a better library/tutorial) I would greatly appreciate it!

Answer 1

From the same link you went to:

Why do I see a warning about “No appenders found for logger” and “Please configure log4j properly”?

This occurs when the default configuration files log4j.properties and
log4j.xml can not be found and the application performs no explicit
configuration. log4j uses Thread.getContextClassLoader().getResource()
to locate the default configuration files and does not directly check
the file system. Knowing the appropriate location to place
log4j.properties or log4j.xml requires understanding the search
strategy of the class loader in use. log4j does not provide a default
configuration since output to the console or to the file system may be
prohibited in some environments.

Also:

Why can’t log4j find my properties file in a J2EE or WAR application?

The short answer: the log4j classes and the properties file are not
within the scope of the same classloader.

The long answer (and what to do about it): J2EE or Servlet containers
utilize Java’s class loading system. Sun changed the way classloading
works with the release of Java 2. In Java 2, classloaders are arranged
in a hierarchial parent-child relationship. When a child classloader
needs to find a class or a resource, it first delegates the request to
the parent.

Log4j only uses the default Class.forName() mechanism for loading
classes. Resources are handled similarly. See the documentation for
java.lang.ClassLoader for more details.

So, if you’re having problems, try loading the class or resource
yourself. If you can’t find it, neither will log4j. 😉