1. Download of JDK
First we can enterClick to enter
this URL to download the required JDK version for installation. This document uses jdk1.8 as an example.
After downloading, find the required jdk download package and download it.
2.JDK installation
Find the installation package and double-click the exe file, as shown in the figure:
Click the Run button in the pop-up window to enter the window below
Just click Next
Configure the environment after installation
3.JDK environment configuration
For Windows 10 or higher operating systems, the click operations are as follows:
Click on the Start menu -> Click on Settings -> Click on System -> Click on System Information -> Click on Advanced system settings
After clicking Advanced System Settings, a system properties pop-up window will appear. Find the Advanced tab and click Environment Configuration. 
A popup will pop up after clicking on the environment variable
In this window, click New in System Variables
Enter in the variable name: JAVA_HOME
Variable value input: JDK installation path
JAVA_HOME
(这是JDK的路径）
Set Path : Edit Path in system variables
Enter variable name: path
Enter the variable value: %JAVA_HOME%\bin (bin here is the bin file path in the JDK)
Path
%JAVA_HOME%\bin (JDK中的bin文件路径）
Set CLASSPATH:
CLASSPATH
.;D:\java\jdk\lib;D:\java\jdk\lib\dt.jar;D:\java\jdk\lib\tools.jar
The above are all the steps for jdk installation!
4 Check whether jdk is installed successfully
win+r to open cmd
Enter javac in the password as shown below, which means the installation is successful.
