CODEWITHSUNDEEP
javaclassproject-structure
TheLovelySausage
TheLovelySausage

Reputation: 4094

Java Single File for External Classes

I believe the Java way is to keep external classes in separate files. So I've ended up with a directory structure like the following

/main/main.java
/main/libs/class01.java
/main/libs/class02.java
/main/libs/class03.java

Which would be fine but some of the classes are really puny little things, for example if all the classes were just

package libs;
import java.util.*;
public class class01 {

    public Integer idno;
    public String name;

    public class01() {}
        idno = 1;
        name = "First";
    }

}

Then separate files seem like they could get a bit excessive. I'm wondering if there is a way to combine them into a single file similar to the way that you can do in .Net C# with namespaces like the following

using System;
using System.Data;

namespace allClasses {

    public class class01 {

        public Integer idno;
        public String name;

        public class01() {}
            idno = 1;
            name = "First";
        }

    }

    public class class02 {

        public Integer idno;
        public String name;

        public class02() {}
            idno = 2;
            name = "Second";
        }

    }

    public class class03 {

        public Integer idno;
        public String name;

        public class03() {}
            idno = 2;
            name = "Third";
        }

    }

}

Which I can use in my main as if they were all separate

using System;

using allClasses;

namespace main_module {

    class main {

        static void Main(string[] args) {

            class01 newClass01 = new class01();
            class02 newClass02 = new class02();
            class03 newClass03 = new class03();

        }

    }

}

I'm sorry for comparing the two it's just that .Net C# is the best example I can show of what I am trying to achieve. I don't know a way of doing this yet in Java, some guidance would be very much appreciated

Upvotes: 0

Views: 53

Answers (1)

Azamat Zhurtbayev
Azamat Zhurtbayev

Reputation: 233

You can declare them as public static class within another public class. E.g.

public class Util {
  public static class A {}
  public static class B {}
}

Then in your main class you can reference them as:

new Util.A();

This will help you combine source code into a single class, but as @oleg-cherednik mentioned, when compiled there will be several separate class files.

Upvotes: 1

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