Question

Pack.java imports pack.TestPack; but it cannot access it. I cannot understand why it cannot access the class despite the import.

Error

Pack.java:7: TestPack() is not public in pack.TestPack; cannot be accessed from outside package
        System.out.println(new TestPack().getHello());  
                           ^
1 error

Pack.java

import pack.TestPack;
import java.io.*;

public class Pack
{
        public static void main(String[] args){
                System.out.println(new TestPack().getHello());
        }
}

TestPack.java

package pack;
import java.util.*;
import java.io.*;

public class TestPack
{
        private String hello="if you see me, you ar inside class TestPack";
        public String getHello(){return hello;}
        TestPack(){}
}

Answer 1

You should make TestPack’s constructor public.

public class TestPack
{
        private String hello="if you see me, you ar inside class TestPack";
        public String getHello(){return hello;}
        public TestPack(){}
}

The thing is, even though TestPack visibility is public, its parameterless constructor visibility is package (which is the visibility when you don’t specify one explicitly).

package visibility means that classes in the same package will be able to see it. Since TestPack and Pack are not in the same package, Pack can’t call TestPack’s constructor.