Stephen Murphy

Thanks for the reply. Turns out that argArray was null. It was the very last thing I checked. Apparently I screwed up the loop that build the argArray and it was just filling up with nulls.

Thanks for the reply.

Also, the API for the method class says that a NullPointerException is thrown if the object in the first argument is null. I have tested for this, and it is not null.

I am having a problem with reflection. I keep getting a NullPointerException and can't figure out why.
It is happening when I call this:
ResponseObject result = (ResponseObject)method.invoke(classInstance, argArray);

I can't figure out what the problem is. I had this reflection working, and then I made some changes to how the argument array was created. In the end, the argarray is the same.
Any ideas?

That was so amazingly obvious. Don't know how I missed a method that adds a collection.

Thanks.

Is there a way to append one vector to the end of another? I was hoping there was a method already in java to do this. Otherwise I'll have to write one myself.

Thanks,
Stephen

Thanks for the reply.
I have figured out my problem, and now have a new one.
Class reflectClass = null; String result = null; Class[] parameterTypes = null; try { reflectClass = Class.forName(componentHandler.getName()); Method[] methods = reflectClass.getMethods(); for (int i = 0; i < methods.length; i++) { if(methods[i].getName() == componentHandler.getMethod()) { parameterTypes = methods[i].getParameterTypes(); } } Method method = reflectClass.getMethod(componentHandler.getMethod(), parameterTypes); result = (String)method.invoke(reflectClass, componentHandler.getInputData().toArray()); System.out.println(result); }

When i get to the Class.forName() call, I get a class not found exception even though the class I am looking for exists and is in the same package.
Any idea why this would happen?

Thanks,
Stephen

Hello
I am learning to use reflection for the first time, and I am having some trouble understanding hte concept. What I need to do for the project I am working on, is take information about a class(name, method name, params) from an XML file, and the reflect the proper method. I understand how to instantiate a class, but it just gets fuzzy from there. THis is what I have so far:

classInstance = Class.forName(componentName).newInstance(); Method method = classInstance.getClass().getMethod(componentHandler.getComponentMethod(), new Class[]{}); result = (String) method.invoke(classInstance, (Object [])componentHandler.getParams());

componentName and the result of getComponentMethod() are both strings. getParams() returns an array of 2 strings.

The params may be anything though when I parse the XML file. Any number of parameters of any type in any order.

Thank you for your help.

Hello

I am trying to implement a application using the SAX Parser. I can do this just fine if the XML input is a file. Is there a way to do this passing that function a XML-formatted string?

If that doesn't make sense, I can try to explain better.

Thanks,
Stephen

Can anyone point me in the direction of good articles about GUI design and\or Java Swing? I am supposed to be reading an article a week for a class and am having trouble finding articles that are useful.

Thanks,
PM

I am creating a GUI for a bioinformatics application. I need to be able to allow the user to login\logout of the application. Is it necessary to use JAAS to keep the program secure, or should I just use JPassword field to build a login component? Anyone have advice on this?

I am designing a GUI for a project at my college. I have been told to look at security issues. As the project is not web-based, I don't really know what security issues there would be. The GUI will interface with databases using JDBC, so maybe that's where security will come into play. Advice anyone?

I am about to start a big project for my college senior exit. I am designing and implementing a GUI interface. I have been told that unless I can convice my sponsor to upgrade, I need to use 1.4. Is there anywhere that I can find a comparison of the pro's\con's of the two? If anyone can point me towards some resources, I would be grateful.

Thanks.

Thanks, I actually did exactly what you suggested: Math.pow() and check out which index was 0, just about 15 mins before I read your post. Great minds think alike I guess. Thanks for the help. Now I gotta figure out how to do the reverse.

Thanks again.

Originally posted by Kym Thompson:

Or are you just unsure how to turn a non-digit character into a numeric value?

I think that is my problem. I can convert base 8, 2, etc. but the ones that start using chars instead of digits confuse me in java. I was hopeing there was some type of inherent method in java for dealing with this.

It has been suggested that I could just use the int value of a char (corresponds to it's ASCII value) and the multiply that by 128 ^ (position in the string)


String vari = "hello"; int value; value = (int)(vari.charAt(0)) * 128 ^ i;

I was hopeing that would work if I enclosed it in a loop and accumulated the values received, but I'm not sure that it's what I'm looking for. I can't get it to work.

Stephen

I am looking for an algorithm to convert a base 128 number into a base 10 number.

Example:
Learn from the mista

should become
836223910068639560092299063760172789594721

I am having a hard time coming up with a conversion algorithm, b\c of the ASCII characters subbed in for digits after a point in base 128. I would appreciate any help you can give me.
Stephen