Why does an application server need to host APIs

[jjscanada]

When a source code is written in java, APIs are used at that time by importing the package. Once source code is compiled and byte code is created, thats the one installed on servers. So everything needed now is the JRE to execute this byte code, whenever this code is invoked. So even if there is no API installed on application server, as long as JRE is there, this code will be executed. IS it correct ? So where is the need of APIs on application server ?

thanks

 

[Diancecht]

I don't get the question. What do you mean with APIs?

From my understanding, APIs are just a contract, an interface; something not, let's say, phisycal. You can't install them.

Maybe if you provide a concrete example ...

Cheers,
Dian

 

[prosper]

He needs not so professional explanation.
Java provides standard API and library for programmer to use.
You write your Java programming and compile them into byte code with Java Development Kit (JDK).
You can run the byte code on compatible version of JRE. JDK is
used in compiling into byte code and JRE is for running the byte code.
It seems to me that JDK has some powerful function that JRE does not have. Therefore, there is a chance that Application Server needs to have their JDK.
If you download JDK from java.sun.com, you will have JRE included in JDK.

 

[prosper]

Java provides standard API and library for programmer to use.
You write your Java program and compile them into byte code with Java Development Kit (JDK)...

some typing error

 

[Diancecht]

It seems to me that JDK has some powerful function that JRE does not have. Therefore, there is a chance that Application Server needs to have their JDK.

For example, compiling JSPs but still don't understand the original question.

Cheers,
Dian