by, 11-19-2011 at 07:22 PM (1122 Views)
Java programming language is undoubtedly one of the leading programming languages amongst new breed of programming languages. Though it is considered to be the best in the industry, it too has its own limitations, flaws due to certain unavoidable programming constraints which Java follows.
Execution of Java program is said to be slow and it requires more memory when compared with programming languages such as C, C++ etc. Programs written in C, C++ are natively compiled, where as Java code is compiled to bytecode. However, since introduction of Just-In Time compilation (JIT) in 1998 by Sun for its Java Virtual Machine the execution of program has become considerably fast.
When compared with programming languages such as C or C++ startup time of Java program is much slow as before being used platform class libraries must be loaded.
This delay in start is mainly because IO-bound operations and not because JVM initialization or class loading. Of course JVM initialization or class loading also has its share to add start up time. It must be noted that the rt.jar file from which JVM must get data itself is huge and constitutes about 40 MB. To improve the start up performance, Java has introduced the new Split bytecode verification technique. However, for large programs its use has made no significant change in startup (about 5% startup improvement).
To improve upon this in future Java has planned to preload the class data at operating system startup itself to get data from virtual memory rather than disk.