Modify the system environment variable cmd command

We have some simple understanding of the use of CMD, but the main problem that bothers us is:

The cmd command modifies the environment variable in two ways: 1, effective in the short term, and automatically expires after the DOS window is closed

2, long-term effective, close the DOS window is still valid

Here is a detailed description:

First (short-term effective)

Set environment variable NAME = environment variable Value

is to use the SET command to set Java_home environment variables (divided into direct assignment and append assignment) The second: long-term effective to find Cmd.exe files (usually under C:\Windows\system32\), as an administrator to open the cmd file setx/m environment variable name " Environment variable Value "is the modified Java_home value please leave a message if you have any questions.

Modify the system environment variable cmd command