Most programmers learn early in their careers that portable programs are as elusive as they
are desirable. While the quest for a way to create efficient, portable (platform-independent)
programs is nearly as old as the discipline of programming itself, it had taken a back seat to
other, more pressing problems. Further, because (at that time) much of the computer world
had divided itself into the three competing camps of Intel, Macintosh, and UNIX, most
programmers stayed within their fortified boundaries, and the urgent need for portable
code was reduced. However, with the advent of the Internet and the Web, the old problem
of portability returned with a vengeance. After all, the Internet consists of a diverse,
distributed universe populated with various types of computers, operating systems, and
CPUs. Even though many kinds of platforms are attached to the Internet, users would like
them all to be able to run the same program. What was once an irritating but low-priority
problem had become a high-profile necessity.
By 1993, it became obvious to members of the Java design team that the problems of
portability frequently encountered when creating code for embedded controllers are also
found when attempting to create code for the Internet. In fact, the same problem that Java
was initially designed to solve on a small scale could also be applied to the Internet on a
large scale. This realization caused the focus of Java to switch from consumer electronics
to Internet programming. So, while the desire for an architecture-neutral programming
language provided the initial spark, the Internet ultimately led to Java's large-scale success.
As mentioned earlier, Java derives much of its character from C and C++. This is by
intent. The Java designers knew that using the familiar syntax of C and echoing the
object-oriented features of C++ would make their language appealing to the legions of
experienced C/C++ programmers. In addition to the surface similarities, Java shares some
of the other attributes that helped make C and C++ successful. First, Java was designed,
tested, and refined by real, working programmers. It is a language grounded in the needs
and experiences of the people who devised it. Thus, Java is a programmer 's language.
Second, Java is cohesive and logically consistent. Third, except for those constraints
imposed by the Internet environment, Java gives you, the programmer, full control. If you
program well, your programs reflect it. If you program poorly, your programs reflect that,
too. Put differently, Java is not a language with training wheels. It is a language for
professional programmers.
Because of the similarities between Java and C++, it is tempting to think of Java as simply
the "Internet version of C++." However, to do so would be a large mistake. Java has significant
practical and philosophical differences. While it is true that Java was influenced by C++, it is
not an enhanced version of C++. For example, Java is neither upwardly nor downwardly
compatible with C++. Of course, the similarities with C++ are significant, and if you are a
C++ programmer, then you will feel right at home with Java. One other point: Java was not
designed to replace C++. Java was designed to solve a certain set of problems. C++ was
designed to solve a different set of problems. Both will coexist for many years to come.
As mentioned at the start of this chapter, computer languages evolve for two reasons:
to adapt to changes in environment and to implement advances in the art of programming.
The environmental change that prompted Java was the need for platform-independent
programs destined for distribution on the Internet. However, Java also embodies changes
in the way that people approach the writing of programs. For example, Java enhanced
and refined the object-oriented paradigm used by C++, added integrated support for
multithreading, and provided a library that simplified Internet access. In the final analysis,
though, it was not the individual features of Java that made it so remarkable. Rather, it was
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