This tutorial explains how to use the PATH and CLASSPATH environment variables on Microsoft Windows, Solaris, and Linux. Consult the installation instructions included with your installation of the Java Development Kit (JDK) software bundle for current information.
After installing the software, the JDK directory will have the structure shown below.
The bin directory contains both the compiler and the launcher.
After installing the software, the JDK directory will have the structure shown below.
The bin directory contains both the compiler and the launcher.
Update the PATH Environment Variable (Microsoft Windows)
Set the PATH environment variable if you want to be able to run the executables (javac.exe, java.exe, javadoc.exe, and so on) from any directory without having to type the full path of the command. If you do not set the PATH variable, you need to specify the full path to the executable every time you run it, such as:
C:\Java\jdk1.6.0\bin\javac TestMyClass.java
It is useful to set the PATH environment variable permanently so it will persist after rebooting. To make a permanent change to the PATH variable, use the System icon in the Control Panel. The precise procedure varies depending on the version of Windows:
Windows XP
- Select Start, select Control Panel. double click System, and select the Advanced tab.
- Click Environment Variables. In the section System Variables, find the PATH environment variable and select it. Click Edit. If the PATH environment variable does not exist, click New.
- In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.
Windows Vista
- From the desktop, right click the My Computer icon.
- Choose Properties from the context menu.
- Click the Advanced tab (Advanced system settings link in Vista).
- Click Environment Variables. In the section System Variables, find the PATH environment variable and select it. Click Edit. If the PATH environment variable does not exist, click New.
- In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.
Windows 7
- From the desktop, right click the Computer icon.
- Choose Properties from the context menu.
- Click the Advanced system settings link.
- Click Environment Variables. In the section System Variables, find the PATH environment variable and select it. Click Edit. If the PATH environment variable does not exist, click New.
- In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.
Update the PATH Variable (Solaris and Linux)
You can run the JDK just fine without setting the PATH variable, or you can optionally set it as a convenience. However, you should set the path variable if you want to be able to run the executables (javac, java, javadoc, and so on) from any directory without having to type the full path of the command. If you do not set the PATH variable, you need to specify the full path to the executable every time you run it, such as:
% /usr/local/jdk1.6.0/bin/javac TestMyClass.java
To find out if the path is properly set, rule below command on console:
% java -version
This will print the version of the java tool, if it can find it. If the version is old or you get the error java: Command not found, then the path is not properly set.
To set the path permanently, set the path in your startup file.
For C shell (csh), edit the startup file (~/.cshrc):
To set the path permanently, set the path in your startup file.
For C shell (csh), edit the startup file (~/.cshrc):
set path=(/usr/local/jdk1.7.0/bin $path)
For bash, edit the startup file (~/.bashrc):
PATH=/usr/local/jdk1.7.0/bin:$PATH
export PATH
For ksh, the startup file is named by the environment variable, ENV. To set the path:
PATH=/usr/local/jdk1.7.0/bin:$PATH
export PATH
For sh, edit the profile file (~/.profile):
PATH=/usr/local/jdk1.7.0/bin:$PATH
export PATH
Then load the startup file and verify that the path is set by repeating the java command:
For C shell (csh):
% source ~/.cshrc
% java -version
For ksh, bash, or sh:
% . /.profile
% java -version
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