General Java Questions I

the design of your application. You should fix this instead of using dirty tricks like the

above.

Carl Rosenberger

db4o   database for objects   

http://www.db4o.com

Q: If anybody can provide some tips on how to design this smartly...

Q: I am facing a problem that might sound common to you all. I have to write a

switch statement with 40 case statement. I am wondering if there can be some way to

reduce this. If anybody can provide some tips on how to design this smartly. ;)

Answer: The alternatives are:

an array you index into to get values or delegates.

an array you binary search.

Roedy Green

 Q: I want to use some java variables , across multiple java files. Is there some

thing like a "extern in C" in java ??

Answer: If you want to share constants, the usual way is to create a class like this:

public class My_Constants {

    public static final int ID_OK = 1;

    public static final int ID_CANCEL = 2;

    public static final String MSG_OK = "Okay.";

    public static final String MSG_ERROR = "An error occurred.";

}

If you want to share a single object instance across your application, use the

Singleton pattern.

Actually, the more common way is to create an interface, like this:

public interface MyConstants{ // Note naming conventions

    int ID_OK=1; // public static final is implicit in interfaces

    // etc

}

Then anyone who wishes to use the constants without putting MyConstants before

each reference can simply implement the interface.

by Gerhard Haring, Jon Skeet

 Q: Does anyone know what the character limit for a class name would be?

I have my class name in a variable ft and I am doing a Class.forName(ft);

My class name with qualifiers is 44 characters long, I can only imagine that there

must be a limit ....

Answer: From the JVM Spec 2   4.2

Class and interface names...fully qualified name...as

CONSTANT_Utf8_info.

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