How To Set Classpath For Java In Cmd

Learn how to prepare classpath in Java either equally an environment variable and pass as the command-line argument. During runtime of whatever Java application, the CLASSPATH is a parameter that tells the JVM where to await for classes and packages.

The default value of the classpath is "." (dot), meaning that only the electric current directory is searched for dependencies.
Specifying either the CLASSPATH surround variable or the -cp command line switch overrides this value.
The lodge in which you specify multiple classpath entries is important. The Java interpreter will look for classes in the directories in the order they appear in the classpath variable.

Coffee Classpath separators are OS specific.

Windows – ; [Semicolon]
Linux/Unix – : [Colon]

ane. Setting `CLASSPATH` as Environs Variable

When yous have set up the location of jar files that are always required during the awarding runtime, and so information technology'southward probably the best to add them in the machine's environment variable 'CLASSPATH'.

During application runtime, application form loader will always scan the jar files and classes at specified paths in this variable.

To set CLASSPATH environment variable, find the location of user environment variables in your machine and add all paths where Jar files are stored. Use the separator between different ii folders, jar files or classes.

You can find the user environment variables window by –

From the desktop, right click the Figurer icon.
Cull Properties from the context menu.
Click the Advanced system settings link.
Click Environs Variables. In the section Organisation Variables, find the CLASSPATH environment variable and select it. Click Edit. If the CLASSPATH environment variable does not exist, click New.
Add together all folders separated with separator. Click OK. Close all remaining windows by clicking OK.

If you are creating CLASSPATH for the showtime fourth dimension, you need to specify the proper name for Variable Proper noun in the Windows 10. Use '.' (dot) to denote electric current directory.

two. Setting CLASSPATH from Control Line

Use -classpath argument to set up classpath from command prompt/console. Apply beneath given commands to set classpath for unlike requirements.

Permit'due south say we have a folder named dependency where JAR files and other classes are placed.

2.1. Add a unmarried jar file in classpath

Below syntax examples will add single jar file in classpath.

//WINDOWS $ prepare CLASSPATH=.;C:\dependency\framework.jar  //Linux/Unix $ export CLASSPATH=.:/dependency/framework.jar

2.2. Add together multiple jar files in classpath

Beneath syntax examples will add more than one jar file in classpath. To do so, merely use the delimiter for your operating organization (either ; or :) as a separator between the locations specified for the CLASSPATH.

To add together all JAR files present in a directory, employ wildcard character ('*').

//WINDOWS $ fix CLASSPATH=C:\dependency\framework.jar;C:\location\otherFramework.jar 				 $ fix CLASSPATH=C:\dependency\framework.jar;C:\location\*.jar  //Linux/Unix $ consign CLASSPATH=/dependency/framework.jar:/location/otherFramework.jar  	 $ export CLASSPATH=/dependency/framework.jar:/location/*.jar

2.3. Add multiple classes to classpath

Many times, you may need to add together individual classes in classpath too. To do so, simply add the folder where classfile is present. e.thou. let's say there are five .course files are nowadays in location binder which y'all want to include in classpath.

//WINDOWS $ set CLASSPATH=C:\dependency\*;C:\location  //Linux/Unix $ export CLASSPATH=/dependency/*:/location

Equally a best do, e'er organize all JAR files and application classes within 1 root binder. This may be the workspace for the awarding.

Please note that subdirectories independent within the CLASSPATH would non be loaded. In order to load files that are contained within subdirectories, those directories and/or files must be explicitly listed in the CLASSPATH.

ii.4. Immigration Classpath

If your CLASSPATH surround variable was set to a value that is not correct, and so you tin can unset CLASSPATH with specifying empty value to information technology.

set CLASSPATH=

3. Executing programs with '-classpath' or '-cp' pick in Java

Apart from setting classpath to the environment variable, you can pass additional classpath to Coffee runtime while launching the application using –classpath selection or –cp option.

Use the . (dot) to include the current path into the classpath where the .class file has been generated.

$ javac –classpath C:\dependency\framework.jar MyApp.Java $ java –classpath .;C:\dependency\framework.jar MyApp

4. How to Find and Print `CLASSPATH` Value

Someday yous wish to verify all path entries in CLASSPATH variable, yous can verify using repeat command.

//Windows c:/> echo %CLASSPATH%  //Linux/Unix $ echo $CLASSPATH

If CLASSPATH is not set yous will go a CLASSPATH: Undefined variable fault (Solaris or Linux) console or only %CLASSPATH% printed in windows command prompt.

Happy Learning !!