CODEWITHSUNDEEP
javacompilationjavac
Red
Red

Reputation: 674

Compile package with java

I have these programs in java:

//file ../src/com/scjaexam/tutorial/GreetingsUniverse.java
package com.scjaexam.tutorial;
public class GreetingsUniverse {
    public static void main(String[] args) {
        System.out.println("Greetings, Universe!");
        Earth e = new Earth();
    }
}

//file ../src/com/scjaexam/tutorial/planets/Earth.java
package com.scjaexam.tutorial.planets;    
public class Earth {
    public Earth() {
        System.out.println("Hello from Earth!");
    }
}

I am able to compile with no error the second one using:

javac -d classes src/com/scjaexam/tutorial/planets/Earth.java

This puts the compiled file Earth.class in the ../classes/com/scjaexam/tutorial/planets/ folder as expected. Now I have to compile the main class GreetingsUniverse.java but this command fails:

javac -d classes -cp classes src/com/scjaexam/tutorial/GreetingsUniverse.java

src/com/scjaexam/tutorial/GreetingsUniverse.java:7: error: cannot find symbol
        Earth e = new Earth();
        ^
  symbol:   class Earth
  location: class GreetingsUniverse
src/com/scjaexam/tutorial/GreetingsUniverse.java:7: error: cannot find symbol
        Earth e = new Earth();
                      ^
  symbol:   class Earth
  location: class GreetingsUniverse

What is the right command to compile (and then tu run) this program?

Upvotes: 1

Views: 468

Answers (3)

Troubleshoot
Troubleshoot

Reputation: 1846

You're trying to create an instance of the Earth object, however that is in a seperate package meaning it can't find it. You need to import the Earth class in your GreetingsUniverse class using:

import com.scjaexam.tutorial.planets.Earth;

Upvotes: 1

Bucket
Bucket

Reputation: 7521

You need to import Earth:

package com.scjaexam.tutorial;

import com.scjaexam.tutorial.planets.Earth;

public class GreetingsUniverse {
    public static void main(String[] args) {
        System.out.println("Greetings, Universe!");
        Earth e = new Earth();
    }
}

When the compiler says "cannot find symbol: class Earth", it is referring to the class you did not import. Be sure to include all packages you use in your class before your class declaration.

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1500525

You haven't imported the Earth class, so the compiler doesn't know what Earth refers to. You should have this line at the start of your GreeingsUniverse.java file:

import com.scjaexam.tutorial.planets.Earth;

Upvotes: 2

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