Java is a cross-platform programming language, so we must first know what a platform is.We call the CPU processor and operating system as a whole a platform.
Programs compiled using a specific compiler can only run on the corresponding platform. It can also be said that the compiler is platform-related, and the compiled files are also platform-related. Thelanguage cross-platform we are talking about is the cross-platform of compiled files, not the cross-platform of the source program.
How to achieve cross-platform java:
What is platform independence
Platform independence is The running of this language on the computer is not restricted by the platform. It is compiled once and executed everywhere.
In other words,executable binary programs created with Java can run on multiple platforms without changes. Java reduces the complexity of development and deployment of multiple platforms. Cost and time.
Achievement of platform independence
The important roles played by it are Java language specification, Class file, Java Virtual Machine (JVN), etc.
In the computer world, computers only know 0 and 1. Therefore, what is actually executed is a binary file composed of 0 and 1.
The C, C, Java, and python used in daily development are all high-level languages, not binary languages. Therefore, if we want the computer to understand the Java code we write, we need to translate it into 0 and 1 binary file. This process is called compilation. The tool responsible for this process is called a compiler.
If you want to compile Java files into binary files, you need to go through two steps of compilation, front-end compilation and back-end compilation.
Support for Java's platform independence is distributed throughout the Java architecture.
The Java language specification, Class file, Java virtual machine, etc. play an important role.
Java Language Specification
By stipulating the value range and behavior of basic data types in the Java language.
Class file
All Java files must be compiled into a unified Class file.
Java Virtual Machine
Convert the Class file into a binary file corresponding to the platform through the Java virtual machine. The platform independence of Java is based on the platform of the Java virtual machine. On the basis of security, it is because the Java virtual machine shields the differences in the underlying operating system and hardware.
For more java knowledge, please pay attention to thejava basic tutorialcolumn.
The above is the detailed content of How java is cross-platform. For more information, please follow other related articles on the PHP Chinese website!