Reinstalled the computer today, and began to reinstall and configure various tools.
1.jdk installation configuration:
1.1 Download jdk1.8.0_171 from the official website
1.2 The installation path is shown in the following figure:
1.3 Configure environment variables:
1.3.1 This Computer -> Advanced System Settings -> Environment Variables ->
In user variables:
Create a new java_home (capitalized), select the d:/java directory
Click the Path variable to edit -> click New -> select the jdk/bin directory
Note: There is no need to configure CLASSPATH, this is what the jdk version did ten years ago, and don't care about the jre directory under the "java" directory.
(OK)
1.3.2 Test:
cmd-> Enter java, javac respectively. No error is reported, and the configuration is successful.