jdk configuration environment variables

The first step: first configure the PATH : such as E:\Program Files\Java\jdk1.8.0_171\bin

Step 2: Create a new JAVA_HOME: such as E:\Program Files\Java\jdk1.8.0_171

Step 3: New CLASSPATH: .;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar;

The fourth step of testing: java -version