Only one public class in one file in Java

[Saishradha Mohanty]

Why can't more than 1 public classes be present in a single JAVA file?

[Stephan van Hulst]

Because that's just how the designers wanted it to be.

They probably did it to reduce the amount of time that compilers need to find out what file a class description is in.

[Daniel Cox]

 

Stephan van Hulst wrote:They probably did it to reduce the amount of time that compilers need to find out what file a class description is in.

The JLS supports your insightful comment

This restriction makes it easy for a Java compiler to find a named class within a package.

For example, the source code for a public type wet.sprocket.Toad would be found in a file Toad.java in the directory wet/sprocket, and the corresponding object code would be found in the file Toad.class in the same directory.

 

[Paweł Baczyński]

 

For example, the source code for a public type wet.sprocket.Toad would be found in a file Toad.java in the directory wet/sprocket, and the corresponding object code would be found in the file Toad.class in the same directory.

Or:
- the source code for a public type wet.sprocket.Toad would be found in a file sprocket.java in the directory wet, and the corresponding object code would be found in the file sprocket$Toad.class in the same directory.
- the source code for a public type wet.sprocket.Toad would be found in a file wet.java in the . directory, and the corresponding object code would be found in the file wet$sprocket$Toad.class in the same directory.

[Dave Tolls]

And the dev who named their classes either 'wet' or 'sprocket' would be found out on the kerb, holding the contents of their desk in a cardboard box.
;)

[Paweł Baczyński]

 

Dave Tolls wrote:And the dev who named their classes either 'wet' or 'sprocket' would be found out on the kerb, holding the contents of their desk in a cardboard box.
;)

The problem is java and javac don't know about this.

[Campbell Ritchie]

A wet cardboard box, surely.

[Dave Tolls]

Possibly with some sort of amphibian in it.

[Campbell Ritchie]

A newt?