General Java Questions I

   ...

}

it is not working for me. Is there any workaround?

Answer: If the source and the text file are in the jar file, then you access the file by:

URL fileURL = getClass().getResource("file.txt");

You can then read the file by using a reader (or whatever you choose),

e.g.:

_istream = new BufferedReader( new

InputStreamReader(fileURL.openStream()) );

j o h n e w e b e r

Or, simpler

getClass().getResourcesAsStream("file.txt"), but you must be sure that

file is in the same directory ( package ) as your class, otherwise you

need play with getClassLoader().getResourceAsStream( "/file.txt" );

Oleg

Q: Difference between loading and instantiating a class???

Well, the subject says it all. What is the difference between loading and instantiating

a class in a JVM.

Second question: What would happen if at runtime I update a class file? Will the JVM

know to use that instead?

Answer: The difference is that when a class is loaded by a ClassLoader it is read in

as a stream of bytes, presumably from a file, but it could just as easily be from over

the network, and then processed or "cooked" into a representation that the VM can

use to make instances of Objects of that classes type. This last part is the

instantiation. You can load a class at runtime with:

Class.forName( "MyClass" );

and instantiate one with:

MyClass mc = Class.forName( "MyClass" ).newInstance();

Cool, ehh. You don t have to know the name of a class at compile time.

>Second question: What would happen if at runtime I update a class file?

>Will the JVM know to use that instead?

Loaded classes are cached because it s quite costly to do the "cooking" I mentioned

above. So it will not be loaded. You may create a separate ClassLoader with new

SecureClassLoader but that will cause all classes _it_ loads to be loaded from this

new ClassLoader but that s not what

you want.

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