Under Linux system, install jdk and configure environment variables

1. First enter the usr folder

2. Go to local again, you can see the previously downloaded package jdk -7....rpm , /usr/local 

3. First check whether jdk is installed, and then use RPM to decompress

4. Check the installation path after jdk is decompressed: /usr/java/jdk/1.7.0.80 (the java folder is automatically created by decompression)

5. After the jdk is installed, check it out:

6. Configure JDK environment variables: enter the configuration file /etc/profile and modify it

7. After entering /etc/profile, add the following:

8. After the environment variables are configured, we need to verify the success: java -version /javac -version