ubuntu - Java - Error : Could not find or load main class

I am getting a Error while I am trying to run java file from the
terminal...

java
version...

java version
            "1.8.0_181"
Java(TM) SE Runtime Environment (build
            1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed
            mode)

javac
version

javac
            1.8.0_181

I have a
java file name Test4 with a
main.

I am running this
command to create a java
class

/opt/Tests/Test4/src/test4>
            javac -cp "/opt/glassfish5/glassfish/lib/*"
            
Test4.java

and
it work successfully , I am getting the Test4.class
file

now I am trying to run the java
command:

/opt/Tests/Test4/src/test4>
            java -cp "/opt/glassfish5/glassfish/lib/*"
            Test4

and getting

Error: Could not find
            or load main class
            Test4

also

/opt/Tests/Test4/src>
            java -cp "/opt/glassfish5/glassfish/lib/*"
            test4.Test4

still
Error: Could not find or load main class
Test4

also

/opt/Tests/Test4/src/test4>
            java -cp "/opt/glassfish5/glassfish/lib/*"
            
Test4.class

still
Error: Could not find or load main class
Test4

also

/opt/Tests/Test4/src>
            java -cp "/opt/glassfish5/glassfish/lib/*"
            
test4.Test4.class

still
Error: Could not find or load main class
Test4

You can find below my class
:

package
            test4;




import
            java.util.Hashtable;
import java.util.Map;
import
            java.util.Properties;
import javax.jms.Connection;
import
            javax.jms.Queue;
import javax.jms.ConnectionFactory;
import
            javax.jms.JMSContext;
import
            javax.jms.JMSException;

import
            javax.jms.JMSProducer;
import javax.jms.QueueConnection;
import
            javax.jms.QueueConnectionFactory;
import
            javax.naming.Context;
import javax.naming.InitialContext;
import
            javax.naming.NamingException;

/**
*
* @author
            zion

*/
public class Test4
            {

/**
 * @param args the command line
            arguments
 */
public static void main(String[] args) throws
            NamingException {

 Context initialContext =
            Test4.getInitialContext();


 ConnectionFactory
            connectionFactory =
            (ConnectionFactory)initialContext.lookup("jms/connection");


            JMSContext jMSContext = connectionFactory.createContext();
 Queue myQueue =
            (Queue)initialContext.lookup("jms/myQueue");
 JMSProducer jMSProducer =
            jMSContext.createProducer();
 jMSProducer.send(myQueue, "Hi,Zion");

            System.out.println("work work work wrok
            wrok");
}




 public static
            Context getInitialContext() throws NamingException{
 Hashtable env = new
            Hashtable();
 env.put(Context.INITIAL_CONTEXT_FACTORY,
            "com.sun.enterprise.naming.impl.SerialInitContextFactory");

            env.put(Context.STATE_FACTORIES,
            "com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl");

            env.put(Context.URL_PKG_PREFIXES, "com.sun.enterprise.naming");

            env.put("org.omg.CORBA.ORBInitialHost", "IP");

            env.put("org.omg.CORBA.ORBInitialPort", "Port");

 return new
            InitialContext(env);

}

}

Inside
the folder
:

/opt/Tests/Test4/src/test4#
            ls
Test4.class
            Test4.java

class="post-text" itemprop="text">

class="normal">Answer

You need
to include your Test4 class file to the classpath.

Assuming your Test4.class file is located on
/opt/Tests/Test4/src/test4 and the fully qualified name is
test4.Test4 then you should do something
like:

/opt/Tests/Test4/src> java
-cp "/opt/glassfish5/glassfish/lib/*":"."
test4.Test4

Note that the directory
of the terminal is /opt/Tests/Test4/src and not
/opt/Tests/Test4/src/test4

Hope this
helps