Question

How do I compile and run the following programs:

Test1.java:

package A;

public class Test1
{
    public int a = 1;
}

Test2.java:

package B;

import A.*;

public class Test2
{
    public static void main(String [] args)
    {
        Test1 obj = new Test1();
        System.out.println(obj.a);
    }
}

I’m new to packages.
If I compile using javac *.java
and manually create dir A, copy Test1.class into it and manually create dir B and copy Test2.class into it and then run java B.Test2 it works. I’m sure this is not the right way of doing it. Please suggest.

Answer 1

You need to keep your java files in the correct directory structure:

A/Test1.java
B/Test2.java

It’s usually sufficient to only invoke javac on your main class, as all dependencies will be handled automatically. After I say javac B/Test2.java, it looks like this:

A/Test1.class
A/Test1.java
B/Test2.class
B/Test2.java

And I can run the program with java B.Test2.

If it’s not enough just to run javac on your main class, you’ll probably need a build system.