query

[ajay_kumar_rana]

Need to know is it necessary that the source file name matches the name of one of the java classes present in it.?

[Lave Kulshreshtha]

Name of java file should be same as the public class present inside it.

-Lave

Originally posted by AjayKumarRana:
Need to know is it necessary that the source file name matches the name of one of the java classes present in it.?

[Sunny Jain]

Actually this is not necessary..!!!
but it is a good programing practice if you do so..!! I tell how it works:

Suppose you have one java file name : Hi.java
inside this you have following code :

  
public class Hello {
 public static void main(String[] args) {
  System.out.println("Hello");
 }
}
  

If you compile this code, this will compile fine..But after compilation..it generate a class file..The name of class file is decided by compiler..and compiler pick the same name as that of parent class in the java file ..so after compilation the class file generated will be : Hello.class

So in order to avoid confusion..it is always a good practice to keep source file name as that of parent class name.

[Rob Spoor]

As Lave said,

Name of java file should be same as the public class present inside it.

I highlighted the word "public", since you CAN have a different name as long as all classes have default access (i.e. no public, protected or private). As soon as there is one public class (and there can be only one per file), the file name MUST be the same as that class name.

[rakesh sugirtharaj]

You can have n number of non public classes in a file that has a different name(not any of the class names).

[Raj Kumar Bindal]

Hi Sunny,

Your explanation seems wrong atleast for java 1.5.
You should have written:

class Hello 
{
 public static void main(String[] args) 
   { 
     System.out.println("Hello"); 
   }
}

instead of :

public class Hello 
{
 public static void main(String[] args) 
   { 
     System.out.println("Hello"); 
   }
}

[Puneet Mittal]

i agree with the above point that we can define n number of non public classes in a file.but what if i define some around three non public classes and all the three classes containing main method and each class givin cal to other class's main method.
check this link and explain me please.

http://www.coderanch.com/t/411098/java/java/why-code-runs-successfully