configuring Eclipse for Art and Science of Java exercises

[kwamifolds]

Hi!!! I know this was discussed in another thread on this website but I can't find it now that I've registered...

I'm doing the Stanford / iTunes U Programming Methodology Course, reading "The Art and Science of Java" and using Eclipse (the stanford version and also toying with a newer version)

I want to do the exercises in the book but every time I try to get the code up in Eclipse it tells me my classes don't exist or whatever. Yes I have imported the acm.jar file and it still goes weird.

I'm just trying to run "Hello World." I've imported EVERYTHING from the acm.jar for my project. It keeps telling me it doesn't recognise the classes I want to use. Here's the code from the book I'm trying to plug in:



import acm.graphics.*;
import.acm.program.*;

public class HelloWorld extends GraphicsProgram {
public void run() {
add(newGLabel("hello, world", 100, 75));
}
}


Sorry for the n00b question but I just want to get this up and running so I can do the exercises! This book wasn't cheap. Eclipse is completely confusing for someone just learning this stuff.

[DarrylBurke]

Moved from New to Java

db

[doWhile]

Is the acm.jar library on the classpath?

[kwamifolds]

Is the acm.jar library on the classpath?

I'm not sure! How do I do that? For the record I did search "classpath" in the Help tab (before this thread) and nothing came up.

[kwamifolds]

Alright I googled the bejesus out of how to make a classpath and still no dice.

Here's what I do in eclipse (latest version):

Create a new java project
Import Archive File -> import acm.jar into my only project folder
Create a new class which I'm calling HelloWorld.java
Fill that class with the previously mentioned code, verbatim
Right click on the acm, click on the "Build Path" menu, select "Use as source folder"
Then all the error messages go away from the code in HelloWorld.java
I try to Run this and get the messages:

Start: applet not initialized
and in the bottom window on eclipse I see:

java.lang.ClassNotFoundException: HelloWorld.class
at sun.applet.AppletClassLoader.findClass(AppletClass Loader.java:211)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.applet.AppletClassLoader.loadClass(AppletClass Loader.java:144)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 47)
at sun.applet.AppletClassLoader.loadCode(AppletClassL oader.java:662)
at sun.applet.AppletPanel.createApplet(AppletPanel.ja va:807)
at sun.applet.AppletPanel.runLoader(AppletPanel.java: 714)
at sun.applet.AppletPanel.run(AppletPanel.java:368)
at java.lang.Thread.run(Thread.java:680)
load: class HelloWorld.class not found.


Why did I get a .java file when I clicked "create new class" instead of a .class? WHat am I missing?

[DarrylBurke]

Why did I get a .java file when I clicked "create new class" instead of a .class? WHat am I missing?

The fundamentals, which you can learn here: Trail: Getting Started (The Java™ Tutorials)

db

[doWhile]

Why did I get a .java file when I clicked "create new class" instead of a .class? WHat am I missing?

If you are this new to java programming, I highly recommend against using Eclipse, but rather use the command line as explained in the the link in post 6. If you forge directly into Eclipse, you will miss many fundamental concepts. If you insist on using Eclipse, there are ample examples for how to add libraries to the classpath: Project Properties -> Java Build Path -> Libraries.