help a 1st timer import library in NetBeans IDE

[Stan Austin]

Hi everyone,
Hopefully this can be answered easily enough.
Last Thursday I was introduced to libraries, namely stdlib, of; http://introcs.cs.princeton.edu/java/stdlib/
I downloaded, StdIn.java and StdOut.java, to the folder I was writing the program in. (this was using ubuntu OS, and the terminal)
Then compiled to get the .class file, and I don't think I had to write import or anything in my program.
I am now trying to do this at home on Win10 OS, using NetBeans IDE,
I have downloaded the library (its in my Downloads folder)
Then right clicked on the libraries tab under the program name, add library, create, created library called "StdLib", added the jar file (added it both to class path and sources)

Then i have written the following code

package stddevandavg;
import StdIn.java;
public class StdDevAndAvg {
    public static void main(String[] args) {
        int a = Integer.parseInt(args[0]);
        int b = (StdIn.readInt());
        System.out.println(a);
        System.out.println(b);
    }
}

also tried (import stdlib.jar & import Std.Lib)

but i get a error messages such as
java.lang.ExceptionInInitializerError Caused by: java.lang.RuntimeException: Uncompilable source code - package StdIn does not exist at stddevandavg.StdDevAndAvg.<clinit>(StdDevAndAvg.java:2)
or
java.lang.ExceptionInInitializerError Caused by: java.lang.RuntimeException: Uncompilable source code - package StdLib does not exist at stddevandavg.StdDevAndAvg.<clinit>(StdDevAndAvg.java:2)

Any help greatly appreciated, TIN

[Junilu Lacar]

That's not the right way to specify your import statement.  It looks like those classes don't have package declarations and as such they will be in the default package. To use these classes, your program needs to be in the default package as well; that is, you can't put any package declaration statement in your program.  If you do that, you won't have to specify any import statements for those classes; you just use them directly from your program.

//package stddevandavg;  -- comment out so your program is in the default package, too
//import StdIn.java; -- import doesn't work like this but you don't need it if both your class
//    and the StdIn class are in the default package
public class StdDevAndAvg {
    public static void main(String[] args) {
        int a = Integer.parseInt(args[0]);
        int b = (StdIn.readInt());
        System.out.println(a);
        System.out.println(b);
    }
}

[Knute Snortum]

You can't use the standard jar file to import as it has its class files in the default package.  You need this jar file that has the class files in the package edu.princeton.cs.introcs.  Download it and move it to some location where you'll know where it is.  I usually put it in a folder called lib just under my project folder -- the same folder that has src.  In NetBeans, right-click on the Libraries node in the project window and click Add JAR/Folder.  Search for the jar file and press Open.  Your jar file should appear in the projects window.  Press F5 if it doesn't.  Now you should be able to do this:

import edu.princeton.cs.introcs.StdIn;

[Stan Austin]

Knute Snortum wrote:You can't use the standard jar file to import as it has its class files in the default package.  You need this jar file that has the class files in the package edu.princeton.cs.introcs.  Download it and move it to some location where you'll know where it is.  I usually put it in a folder called lib just under my project folder -- the same folder that has src.  In NetBeans, right-click on the Libraries node in the project window and click Add JAR/Folder.  Search for the jar file and press Open.  Your jar file should appear in the projects window.  Press F5 if it doesn't.  Now you should be able to do this:

import edu.princeton.cs.introcs.StdIn;

Sweet thank you, for the link and instructions.
I couldnt get Junilu's method to work, but this did the trick.
A little bit annoying that its not just called import stldlib-package.StdIn, that would be much more user friendly lol.