How to run java files from different packages in command prompt?

Question

I need to run a java program in Windows using the command prompt. JAVAC is running perfectly in my computer. However, when I tried to compile my code (javac sampleprog.java), it displayed an error saying that it can't find the imported packages and classes I used in the program. What command should I use? Or how could I solve this? My java programs are stored in different packages and this sampleprog.java uses an API and calls different methods from different classes.

Thanks!

Answer 1

Navigate to the directory that contains the compiled class files eg c:\\myproj\\classes

Then invoke java com.myproject.MyClass where com.myproject.MyClass is the fully qualified path to MyClass.

If you have dependencies on third party libraries you may also need to add the -classpath flag eg java -classpath c:\\path\\to\\some\\lib.jar com.myproject.MyClass

Answer 2

使用javac编译之后，可以使用java YourFile运行它

Answer 3

Go to root of your class files. For example c:/proj/classes . If your class name is MyClass and it belongs to package com.mycompany you should find file com/mycompany/MyClass.class there.

If so type in command prompt java com.mycompany.MyClass and press ENTER.

Pay attention that when you are using javac you have to type the extension *.java , however when you are running the class you have not type extension .class . The string com.mycompany.MyClass is called fully qualified class name . This name is used by JVM to load class.