0After installation of JAVA, we need to setup 2 environment variables. First one is JAVA_HOME and second is Path.
Below steps to set up Java environment to compile & execute Java programs from command line Or any editor (like Eclipse, NetBeans, etc)
- Download latest version of JDK (as per bit of OS i.e. 32-bit OR 64-bit OS) from Oracle site.
- Install its both components JDK & JRE inside same folder location (recommended).
After installation, 2 sub-folders are created inside Java Folder. One for JDK (Java Development Kit) and other for JRE (Java Runtime Environment).
- Setup JAVA_HOME Environment variable
JAVA_HOME is globally accepted standard variable in JAVA world which represents the JDK location. This variable is internally used by other JAVA based tools / software’s like Eclipse, NetBeans, Tomcat, JBoss, etc to identify the JDK location during start-up / execution of that software’s / tools.
Let’s assume JDK is installed at D:\Program Files\Java\jdk1.8.0_91 location and follow below steps to setup JAVA_HOME environment variable:
Right Click on This PC -> Properties -> Advanced System Settings ->Advanced tab -> Environment Variables button -> Click on New Button to create a User Variable the provide Variable name as
JAVA_HOME and Variable value as D:\Program Files\Java\jdk1.8.0_91 (this location is depend on where You installed your JAVA) -> OK
- Setup PATH Environment variable
JAVA program compile by using javac command (an executable file inside bin folder) and run by using java command (an executable file inside bin folder) and these files reside inside Java\JDK\bin directory.
PATH is globally accepted standard variable in Windows OS which have locations of all executable files (like .exe OR .bat). If we execute any command using Command Line, Windows OS searching these commands under the path specified inside PATH environment variable.
That’s why we need to setup JAVA executable folder location (i.e. bin folder) along with PATH environment variable so that we can compile & run our JAVA programs by residing on any drive (C: OR D:) from command prompt (CMD).
If we don’t setup JAVA executable folder location inside PATH environment variable then we always get below error while compiling or execution our JAVA programs other than Java\bin location.
NOTE: This error is not given by JAVA whereas this is OS error. Whenever you try to execute any unknown command from OS then OS raise this error.
Let’s assume Executable files reside inside JDK is at D:\Program Files\Java\jdk1.8.0_91\bin location and follow below steps to setup PATH environment variable:
Right Click on This PC -> Properties -> Advanced System Settings ->Advanced tab -> Environment Variables button -> Click on New Button to create a User Variable the provide Variable name as PATH and Variable value as %JAVA_HOME%/bin; %PATH% (this location is depend on where You installed your Java) -> OK
%JAVA_HOME% is used to get the value of JAVA_HOME and append older PATH into PATH environment variable.
- Check whether we can compile / execute our JAVA programs using Command prompt or not:
- Open Command Prompt
- Type command Java – version
