How do i change classpath

Java Classpath separators are OS specific. During application runtime, application class loader will always scan the jar files and classes at specified paths in this variable. Use the separator between different two folders, jar files or classes. Use '. Use below given commands to set classpath for different requirements.

Below syntax examples will add more than one jar file in classpath. Many times, you may need to add individual classes in classpath as well. To do so, simply add the folder where classfile is present.

As a best practice, always organize all JAR files and application classes inside one root folder. This may be the workspace for the application.

Apart from setting classpath to the environment variable, you can pass additional classpath to Java runtime while launching the application using —classpath option or —cp option. Use the. Data Structures. Operating System. Computer Network. Compiler Design. Computer Organization. Discrete Mathematics. Ethical Hacking. Computer Graphics. Software Engineering. Web Technology. Cyber Security. C Programming. Control System. Data Mining. Data Warehouse. You only need to set the class path when you want to load a class that is a not in the current directory or in any of its subdirectories, and b not in a location specified by the extensions mechanism.

You should remove any settings that are not application-specific, such as classes. Such settings can remain. Using the -classpath option is preferred over setting the CLASSPATH environment variable because you can set it individually for each application without affecting other applications and without other applications modifying its value. Classes can be stored in directories folders or in archive files.

The Java platform classes are stored in rt. For more details about archives and information about how the class path works, see Class Path and Package Names. That directory exists for use by the JDK software and should not be used for application classes. Application classes should be placed in a directory outside of the JDK directory hierarchy. That way, installing a new JDK does not force you to reinstall application classes.

The following commands have a -classpath option that replaces the path or paths specified by the CLASSPATH environment variable while the tool runs: java , jdb , javac , javah and jdeps. The -classpath option is the recommended option for changing class path settings, because each application can have the class path it needs without interfering with any other application.

The java command also has a -cp option that is an abbreviation for -classpath. For very special cases, both the java and javac commands have options that let you change the path they use to find their own class libraries. Most users will never need to use those options.

The format is:. Each element of the input class path containing a wildcard is replaced by the possibly empty sequence of elements generated by enumerating the JAR files in the named directory. For example, if the directory foo contains a. That is, wildcards are honored in all these cases. However, class path wildcards are not honored in the Class-Path jar-manifest header. Java classes are organized into packages which are mapped to directories in the file system.

But, unlike the file system, whenever you specify a package name, you specify the whole package name -- never part of it.

For example, the package name for java. Button is always specified as java. For example, suppose you want the Java runtime to find a class named Cool. When the app runs, the JVM uses the class path settings to find any other classes defined in the utility.

Note that the entire package name is specified in the command. The class would not be found.