Linux JDK environment variable configuration and testing

======================== Reprint ===========================

Setting environment variables

[[email protected] opt]# vi/etc/profile; Edit the system configuration file

Then enter I and add the following content
==================================================================================
Export Java_home=/usr/java/jdk1.7.0_04
Export classpath=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar
Export path= $PATH: $JAVA _home/bin

Finally press the EXC key, enter the colon, and enter: Wq Save exit

Test

VI Hello.java

Then enter I and add the following content

Class Hello

{

public static void Main (string[] args)

{

System.out.println ("Hello world!");

}

}

Finally, press ESC, enter a colon, and last enter: Wq save exit

Javac Hello.java

Java Hello

If a "Java lang Unsupportedclassversionerror" error occurs

is a version issue:

To change the compile and execute command to:

/usr/java/jdk1.7.0_04/bin/javac Hello.java

/usr/java/jdk1.7.0_04/bin/java Hello

Linux JDK environment variable configuration and testing