General Java Questions I

http://kaffe.org does open source implementation.

I read there: "Kaffe is a cleanroom, open source implementation of a Java virtual

machine and class libraries. It is also a fun project that was started by Tim Wilkinson

and was made successful by the contributions of numerous people from all over the

world.

But Kaffe is not finished yet! You can help by developing new and missing

functionality, porting Kaffe to new platforms, and testing your Java applications under

Kaffe.

Kaffe mostly complies with JDK 1.1, except for a few missing parts.

Parts of it are already JDK 1.2 (Java 2) compatible."

John

http://gcc.gnu.org/java/   The GNU Compiler for the Javatm Programming Language

 Q: I will be thankful if anyone tells me why JVM is called virtual machine.

Answer: JVM is called a virtual machine because there is no real hardware which

interprets the byte code. If you have done any assembly programming for any

microprocessor/microcontroller you will able to understand this. A microprocessor

has builtin instruction set to interpret the assemly code. Similarly the JVM is similar to

a microprocessor in the sense it has its own instruction set but it implemented in

software. That is why it is called a virtual machine! 

 Q: Do anyone know the difference between java and C#.

Answer: They are different languages. Java has been around for about five years. C#

has not been publicly released yet. One is written by Sun Microsystems, one my

Microsoft. They are fairly similar languages with C# having a few extra bits added on

to it. 

Phil

C# bytecodes can be compiled to native exe files just as Java bytecodes can be. But

C# is expected to be more closely tied to the Windows operating system and

standard interfaces that are part and parcel of Windows. Writing a native compiler

that collects all these interfaces and combines them into a unified whole that can run

on ANY operating system may require compiling proprietary windows components

which Microsoft will make sure is hard to do and against its licensing policies. So you

can expect to see native compilers that compile for Windows platforms but

not to other operating systems.

alankarmisra

 Q: I read PHP 4 times faster than JSP. Why then do we need JSP?

Answer: These tools fill somewhat different niches and seldom directly compete.

PHP is good for situations where your page can interact more or less directly with a

database, without the need for complex business logic. Its strength is that it can be

used to build pages VERY quickly. And, as you note, they run very quickly as well.

The JSP/Servlet model is more geared toward distributed n tier applications where

there is at least logical, and possibly physical, separation of model, view, and

controller functions. It is more complex than PHP, but also more scalable, and

well written Java apps may be a great deal more maintainable because of the

separation of logical tiers.

They re both nice tools, and I use both, but I don t think either one is going to kill the

file:///F|/a_jsite/350_tips/general_java I.htm (2 of 33) [2001 07 08 11:24:51]