We often discuss Java technology everywhere, but what exactly is it? The following section will introduce that Java technology is not only a programming language, but also a platform.
#Java technology is a programming language and a platform.
java Programming Language
Java programming language is a high-level language that can be described by the following characteristics:
Simple
Structural neutrality
Object-oriented
Portability
Distributed
High performance
Multi-threading
Reliability
Dynamics
Security
Each of the above buzzwords is introduced in "The Java Language Environment," a white paper written by James Gosling and Henry McGilton .
In the Java programming language, all source codes are written in text files ending with the .java extension;
Then these source files will be compiled into .class through the javac editor document. A .class file does not contain source code, instead, it consists of "bytecode". ——JVM Machine Language;
Then, the java launcher tool will run your application using an instance of the Java Virtual Machine.
Since the Java virtual machine is available on different operating systems, the same .class file can run on Windows, Solaris OS, Linux, Mac OS and other operating systems. Some virtual machines, like Java SE HotSpot at a Glance, improve application performance during runtime. These include: finding performance bottlenecks, recompiling frequently used code fragments, etc.
Java Platform
A platform is a hardware or software environment that supports the running of programs. We often mention some popular platforms, such as windows, linux, solaris OS, Mac OS... Most platforms can be regarded as a combination of operating systems and underlying hardware. The Java platform is different from most other platforms in that it is just a software development platform running on other hardware.
The Java platform has two components:
Java Virtual Machine
JavaAPI
Java Virtual Machine is the foundation of the Java platform And has been ported to a variety of hardware platforms.
JavaAPI is a collection of software components that provides many useful functions. It is grouped into libraries of related classes or interfaces. The so-called libraries are what we often call packages.
As an independent platform environment, the Java platform is a bit slower than native code. Without threatening portability, the rapid development of compilers and virtual machines has made the Java platform more performant. Close to native code.
The above is the detailed content of What is Java technology. For more information, please follow other related articles on the PHP Chinese website!