Monday, March 31, 2008

History of Java

But C++ was still complex with things like pointers, memory leak and multiple inheritence. The pointer concept was taken from C and it was very messy! The pointer is special type of variable that points to other variables. Since there was no guidelines as to how to use these pointers, it was very easy loose track of them.


In a typical two thousand lines program, one would frequently end up with hundredes of pointers pointing to thousands, some of them are pointers and some just plain variables. Needless to say this made a large program extremely difficult to read and when the programmer left for another company, they would have no other choice than to just throw away his program! It was sometimes necessary to do this even when the programmer was around and very much alive.

This is because the pointers he created inside his program had taken a life of their own and defy every attempt to predict how the program should behave. Memory management was also another weak point of C and C++. The programmer was responsible for cleaning up the memory their program would allocate and use. Failure to do so will result in a crash of the whole computer.


Multiple inheritence, though sparingly used, was another feature of C++ which made a programmer's life miserable. It, however, had its use, especially in job interviews. This one question, they thought, helped them separate the wheat from the chaff.


But C++ still had some nice and simple features, like inheritence, encapsulation, etc. They are something one can describe in plain english, something one can explain to a layman. So the creator of java decided to take the good features of inherience, encapsulation, and polymorphism from C++, while discarding the bad features such as multiple inherience, pointers etc. The memory management was improved in java where the programmer will not be held responsible for memory management. They can clean up after themselves if they want to get extra credit, but they do not need to. Needless to say all these was great news to the tourists in Indonesia!


Java introduced lot of clarity in notations too. For example, in C++ they would say class doctor:person to mean doctor is derived from person. It is obviously very cryptic. The same situation can be expressed in java as class doctor extends person , which is much easier to understand. But there are few awkward stuff in java too especially when someone says class bum extends person (my last bum joke)!


Java made an important contribution in the graphical user interface (GUI) area. C++ was really lacking in expertise here. They visual C++, but worked only on windows environment. But it did not work in UNIX systems or mackintoshes. Just like other features of java, this was also supposed to be platform independent. This was further necessary because one can put some little GUI on a web page which can be views over the internet. And one cannot control what kind of computers other will have.


After a while, it was necessary to call programs from one computer to another computer. To do this, they created J2EE. I am not sure how they came up with the name J2EE. The 'J' of J2EE, of course, means "Java", and I can be reasonably sure '2' stands for 'To'. But I do not know what the 'EE' part is all about, probably some kind of extension. Or at this point they ran out of names to think of. So they decided to have one of those just another vague acronyms.

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