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javadirectory-structureconventions

Why do Java source files go into a directory structure?

as weSuppose that I am creating a Java project with the following classes

  1. com.bharani.ClassOne
  2. com.bharani.ClassTwo
  3. com.bharani.helper.HelperOne
  4. com.bharani.helper.support.HelperTwo

with files put immediately under the folder 'src'

  1. src/ClassOne.java
  2. src/ClassTwo.java
  3. src/HelperOne.java
  4. src/HelperTwo.java

and compile them using the command

$ javac -d classes src/*.java (assuming that classes directory exists)

The compiler compiles these files and put the class files in appropriate sub-directories inside the 'classes' directory like this

  1. classes/com/bharani/ClassOne.class
  2. classes/com/bharani/ClassTwo.class
  3. classes/com/bharani/helper/HelperOne.class
  4. classes/com/bharani/helper/support/HelperTwo.class

Because the spec mandates that the classes should go inside appropriate directory structure. Fine.

My question is this: When I use an IDE such as Eclipse or NetBeans, they create the directory structure for the source code directory ('src' directory here) as well. Why is that? Is it mandatory? Or, is it just a convention?

Thanks.

Solution

  • Mainly convention. It makes sense for the source to mirror the binary structure.

    Also, if you have two classes with the same name (but in different packages), how would you store the source if not in different directories?

    Keeping the source in just one folder is fine for small projects, but once you have a larger project (hundreds of classes), grouping the source into packages makes things far more manageable.