Cannot find symbol error even if they are on the same directory in Java

Question

I have two files in the same directory namely Main.java and Functions.java

The content of Main.java is this:

import java.util.Scanner; 

class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String s = scan.next();

        Functions you = new Functions(s);

        System.out.println("Your name is " + you);
    }
}

And Functions.java:

public class Functions {
    public String name;

    public Functions(String name) {
        this.name = name;
    }

    public String toString() {
        return name;
    }
}

I manually compile and run them on my terminal. So this is what I did:

javac folder1/folder2/*.java And after java folder1/folder2/Main.java

But it gives me an error of this:

error: cannot find symbol
Functions you = new Functions(s);
symbol:   class Functions

Even though they are on the same directory, it will still give an error.

Edit: I interchanged my code for compiling and running. Sorry for that.

Which version of java are you using? Newer java you can just run a .java file. In that case, it will not find Function.class because you have it in a subdirectory. It would need to be in a package in that case. I suspect you can just go to the folder `folder2` and type `java Main` and it should run the compiled version, and it will find Function.class because it is on the classpath. — matt, Jul 15 '20 at 07:48
@matt I am using OpenJDK 13.0.1. I tried changing my working directory to where all the .java files are. Still, when I try to run in my terminal this `java Main.java`, the same error shows up. — John Cymmer, Jul 15 '20 at 08:09
@JohnCymmer Leave off the .java, doing that assumes 'single-source-mode' avoid that at first. Check my answer, do the '.class' files exist after you run javac? If you change directory to folder2 then you can just run `java Main`, again *not Main.java but Main*. — matt, Jul 15 '20 at 08:11
Does this answer your question? https://stackoverflow.com/questions/62872247/different-classes-in-java/62872469 — Stephen C, Jul 15 '20 at 08:31

score 0 · Answer 1 · edited Jul 15 '20 at 08:19

0

run javac Main.java
run java Main

Note 1: You don't need to explicitly compile the files which are being used in the file you're compiling. If Java compiler sees, that you're using class B in the class A, Java will implicitly compile all the classes (including class B) when compiling the container class (class A, in this case).

Note 2: If you're using JDK >=11, then you can just compile+run the program with one command. JEP 330, Launch Single-File Source-Code Programs, is one of the new features introduced in the JDK 11 release. So, you can just run java ClassName.java.

edited Jul 15 '20 at 08:19

Mark Rotteveel

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answered Jul 15 '20 at 07:12

Giorgi Tsiklauri

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Tried it but still won't work. It still cannot find the Class but thank you for the Notes. – John Cymmer Jul 15 '20 at 07:39
JEP 330 is specifically about "single-file source-code programs". Since OP has spread their code over 2 files, it won't help here! And I think that's actually the problem here. – Joachim Sauer Jul 15 '20 at 07:42
@JoachimSauer, I know that it's about single-file. I gave him the solution for the first problem, and then, as a bonus, suggested what he might also find useful. – Giorgi Tsiklauri Jul 15 '20 at 07:51

matt · Answer 2 · 2020-07-15T08:22:09.183

The issue is classpath.

folder1
| folder2
| | Main.java
| | Functions.java

After you run javac folder1/folder2/*.java you'll have class files.

folder1
| folder2
| | Main.class
| | Main.java
| | Functions.class
| | Functions.java

Since your classes are not in a package then folder2 needs to be on the classpath. To run main.

java -cp folder1/folder2 Main

Notice that I left off the .java on the name of the class.

If you don't want to supply the -cp argument (sets the classpath) you can cd folder1/folder2 then you'll be in the folder with the class files. You can just type.

java Main

I tried this with your java files. When it works you won't see any output until you press enter.

Cannot find symbol error even if they are on the same directory in Java

2 Answers2