javac "Cannot find symbol"

[madsovenielsen]

Hello.

Im struggeling with java packages.

I have 2 files:

C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10\Main.java

package javaapplication10;



/**
 *
 * @author admin
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here

        say say = new say();
        System.out.print(say.hello() + "\n");
    }

}

And


C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10\say.java

package javaapplication10;

/**
 *
 * @author admin
 */
public class say {

    public String hello()
    {
        String msg = "hello";
        return msg;
    }
    public String goodbye()
    {
        String msg = "goodbye";
        return msg;
    }
}

when i try to compile i get the following error:

PS C:\Users\admin\Documents\NetBeansProjects\JavaApplication10\src\javaapplication10> javac Main.java
Main.java:22: cannot find symbol
symbol  : class say
location: class javaapplication10.Main
        say say = new say();
        ^
Main.java:22: cannot find symbol
symbol  : class say
location: class javaapplication10.Main
        say say = new say();
                      ^
2 errors

If i comment the package declaration out. i can compile and run the files fine without any problems. i dont understand this. any help is greatly appriciated.

/mads

[tashimoto]

Your code worked on my system, and I'm also using NetBeans. So I'm sure your code is correct. :)

I did a quick search on NetBeans for similar cases, and I found a thread that might be useful: NetBeans Forums - Netbeans claims it cannot find "symbol"

Skip down to Damian's response about clearing the cache. Maybe that is the same thing you are experiencing. Good Luck!

Chris

[madsovenielsen]

I dont know how this shouldt affect the "compiler" as i get this error at compile time.
Anyway i did "clear" the cache. the problem persists.

/mads

[madsovenielsen]

And i only get this "error" when i use package. if i comment the package declaration out. it compiles and runs fine.

[Tolls]

Go up a level and compile from there.
I think the compiler is looking for "say" in a javaapplication10 from where you are running javac, so it can't find it.

[Norm]

When using packages, the class path for the javac command must point to the folder containing the package folder. You can set the classpath up one level by using a classpath something like this:
-classpath .;..\.
Current folder and up one level

[Tolls]

That's the other option...;)

[madsovenielsen]

I can now compile if i follow Norm's advice, compiling from "elevated ground" :)

But now i get a new error:

PS C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10> java Main.java
Exception in thread "main" java.lang.NoClassDefFoundError: Main/java
Caused by: java.lang.ClassNotFoundException: Main.java
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Main.java. Program will exit.
PS C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10>

Again. this works fine without the package declaration.

[JosAH]

I can now compile if i follow Norm's advice, compiling from "elevated ground" :)

But now i get a new error:

PS C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10> java Main.java
Exception in thread "main" java.lang.NoClassDefFoundError: Main/java
Caused by: java.lang.ClassNotFoundException: Main.java
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Main.java. Program will exit.
PS C:\Users\admin\Documents\NetBeansProjects\JavaAppl ication10\src\javaapplication10>

Again. this works fine without the package declaration.

Your class is not named 'Main' it is named 'javaapplication10.Main'.

kind regards,

Jos

[madsovenielsen]

package javaapplication10;



/**
*
* @author admin
*/
public class Main {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here

say say = new say();
System.out.print(say.hello() + "\n");
}

}

My class is named Main.

[Tolls]

It's in the javaapplication10 package, which means it is called javaapplication10.Main.
That's how java naming works.

[madsovenielsen]

package javaapplication10;



/**
*
* @author admin
*/
public class javaapplication10.Main {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here

say say = new say();
System.out.print(say.hello() + "\n");
}

}

I get an error in NetBeans and i get the following error when i try to compile:

javaapplication10\Main.java:14: '{' expected
public class javaapplication10.Main {
^
1 error

[JosAH]

package javaapplication10;



/**
*
* @author admin
*/
public class javaapplication10.Main {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here

say say = new say();
System.out.print(say.hello() + "\n");
}

}

I get an error in NetBeans and i get the following error when i try to compile:

javaapplication10\Main.java:14: '{' expected
public class javaapplication10.Main {
^
1 error

You should read some tutorials first before you drown in classpath issues, compilation problems and your own incorrect fantasy.

kind regards,

Jos

[madsovenielsen]

My code is now like this:

Main.java

package javaapplication10.Main;

import javaapplication10.say.say;

/**
 *
 * @author admin
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here

        say say = new say();
        System.out.print(say.hello() + "\n");
    }

}

say.java

package javaapplication10.say;

/**
 *
 * @author admin
 */
public class say {

    public String hello()
    {
        String msg = "hello";
        return msg;
    }
    public String goodbye()
    {
        String msg = "goodbye";
        return msg;
    }
}

The files is in the directories:

say and Main

i can compile say.java fine. but when i try to compile Main.java get the following error:

Main\Main.java:8: package javaapplication10.say does not exist
import javaapplication10.say.say;
^
Main\Main.java:22: cannot find symbol
symbol : class say
location: class javaapplication10.Main.Main
say say = new say();
^
Main\Main.java:22: cannot find symbol
symbol : class say
location: class javaapplication10.Main.Main
say say = new say();
^
3 errors

I have no errors in NetBeans and i have looked through this "tutorial"

The Java Package Tutorial

Any help is greatly appriciated.

[JosAH]

Now you have two packages: javaapplication10.Main and javaApplication10.say; my guess is that it's not what you want. Study those tutorials and don't be in a hurry.

kind regards,

Jos

[madsovenielsen]

I have now read this one to:
Java - Packages

No help either. i just can't understand this.

Both files, say.java and Main.java reside in the _same_ directory.

[Norm]

java Main.java

The java command is for executing a program.
The javac command is for compiling a program.

In post#8 You are using the wrong command to compile. Use javac

Use: java Main (no file extension)
to execute a class.

[madsovenielsen]

Im sorry. it was a bit unclear.

I have compiled the code succesfully. but when i try to run it i get this error:

PS C:\Users\admin\Documents\NetBeansProjects\JavaApplication10\src\javaapplication10> ls


    Directory: C:\Users\admin\Documents\NetBeansProjects\JavaApplication10\src\javaapplication10


Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-a---        07-10-2010     07:16        646 Main.class
-a---        06-10-2010     21:33        415 Main.java
-a---        07-10-2010     07:16        339 say.class
-a---        06-10-2010     21:09        359 say.java


PS C:\Users\admin\Documents\NetBeansProjects\JavaApplication10\src\javaapplication10> java Main
Exception in thread "main" java.lang.NoClassDefFoundError: Main (wrong name: javaapplication10/Main)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClassCond(Unknown Source)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$000(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Main.  Program will exit.
PS C:\Users\admin\Documents\NetBeansProjects\JavaApplication10\src\javaapplication10>

Again. if i remove the package declaration it compiles and runs fine.

Any help is greatly appriciated

[Eranga]

I'm not totally with this thread, but looking at the last error, are you sure that the package is exist physically that you've mentioned in the class?

[madsovenielsen]

As i understand packages. after reading these tutorials:

Java - Packages
The Java Package Tutorial

A package is just a folder that contains the files. in my situation: javaapplication10

And yes the folder exists. :)