尝试运行时出现Java NoClassDefFound错误

Question

I'm fairly new to working with packages in java but I've got a file structure thats:

• project
  
  • classes
    
    • src
      
      • com
        
        • main
          
          • Billing.class
            
          • Password.class
            
  • src
    
    • com
      
      • main
        
        • Billing.java
          
        • Password.java
          

Each java file has package package src.com.main; at the top. I'm compiling from the project folder using javac -d ./classes/ ./src/com/main/*.java and it compiles fine. When I go to run it using java classes/src/com/main/Billing is gives me a NoClassDefFound exception. What am I doing wrong?

Edit: Entire Error:
java classes/src/com/main/BillingException in thread "main" java.lang.NoClassDefFoundError: classes/src/com/main/Billing (wrong name: src/com/main/Billing) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

Answer 1

Try

cd project/classes/
java -cp . src.com.main.Billing

Answer 2

Your class files are not in the classpath that may be the case.

If you are using maven and eclipse try the command mvn eclipse:eclipse or

you can set the classpath using command prompt also where your .class files are located.

For example:

C:> set CLASSPATH=classpath1;classpath2..

Answer 3

i think you use other class in your class that is on other package or jar file if so! you need to define Class Path to enable java find your dependencies.