A major feature of JAVA ------ does not depend on the platform
JAVA provides a JAVA runtime environment (Java Runtime Environment, JRE) on the platform, the environment is composed of Java Virtual Machine (Java Virtual Machine, JVM), class library, and some core files. The core of the Java virtual machine is the so-called bytecode instruction, which is a sequence code consisting of 0 and 1 that can be recognized and executed by the Java virtual machine. Bytecode is not a machine instruction, because it is not related to a specific platform and cannot be directly recognized and executed by any platform.
Operating principle: Java source files are compiled into bytecode instructions, and the Java virtual machine is responsible for translating the bytecode file into the machine code of the platform where the virtual machine is located, and allowing the current platform to run the machine code.
ps: Indonesia has a very important coffee-producing island called Java, which is translated as Java in Chinese. The developers named this language Java, and its implication is to serve a cup of hot coffee for the world.
Install JDK
Introduction to the 3 platforms
1 Java SE
Java SE is called Java Standard Edition or Java Standard Platform. Using this platform, Java desktop applications and low-end server applications can be developed, and Java Applet programs can also be developed.
2 Java EE
Java EE is called Java Enterprise Edition or Java Enterprise Platform. Enterprise-level service applications can be built using Java EE. The Java EE platform includes the Java SE platform and adds additional class libraries.
3 Java ME
Java ME is called Java Micro Edition or Java Mini Platform. Used in embedded consumer products, such as mobile phones, PDAs, etc.
Install Java SE Platform
Go to Oracle website to download jdk for free
http://www.oracle.com/technetwork/java/javase/downloads/index.html
After the download is complete, click Install. Install to your own favorite directory.
Finally, to configure the system environment variables
Right click on my computer in win10 and go to properties. Then select Advanced system settings.
As shown in the figure:
As shown in the figure:
Add JAVA_HOME variable in system variables
As shown in the figure:
Note: The value of JAVA_HOME is your jdk installation directory.
Then configure the Path variable
As shown in the figure:
Note: There is a dot at the beginning
Finally configure the classpath variable
As shown in the figure:
Note: There is a dot at the beginning
Congratulations, Java SE has been officially installed here.