Overriding acm.program init() method; does Java have to be this hard? - eclipse

Question

Java problems
I am a student of Java. I managed to write about 15 Java programs so far and get them working on the PC. But I have not yet written a init() method like my latest assignment requires in order to initialize some instance variables. The compiler tells me that my init() method is attempting to override the final init() method in the acm.program. Isn’t that what an init() method is supposed to do? After exhausting all avenues on PC for the last week, I thought maybe it is an Eclipse problem on the PC. All the example code in the Java documentation shows little Mac windows. So I thought I would try moving my code to a Mac running Lion OS 10.7.2.
Switching to MAC environment.
The Mac claims to have Java installed but I think it’s just the run time environment, not a development environment. All I could find for applications is the Java VisualVM, which I assume is the virtual machine so there is no java development software. So… I downloaded Eclipse for Mac from Stanford’s website and got Eclipse IDE for Java Developers Version: Helios Service Release 2 and tried to run a simple program which included an import statement.
The import acm.program.*; statement is giving the compiler a problem: "acm cannot be resolved”. After researching this I think the problem is I have not downloaded the acm.jar archive and added that to my build path. Why this isn’t already done for me, as part of Eclipse I have no clue. I guess everything has to be difficult.
So I downloaded the acm.jar archive and it’s sitting in my download folder. I tried double clicking it and thankfully the mac won’t execute it. I tried dragging it into my source folder in Eclipse and then adding it to the build path. Once in the build path, Eclipse tells me the jar is missing. So I removed it from the build path and instead from inside Eclipse went to Properties/Java Build Path/Libraries/add External JARS… and navigated to my downloads folder where the acm.jar folder is to select the JAR. However, Eclipse seems to be looking for a .jar;.zip file, which there are none because my Mac helpfully already unzipped the folder. So I changed the open window to look for all files (.) and now I see individual .java files that are too numerous to add to the build path individually.
So back to the PC and download the acm.jar zip file and copy it over to the Mac in unzipped form and again add it to the build path as a zip file. This resolved the compiler error and my simple program executed on the Mac!
Next I will try my program with the init() method to see if that now works. Nope. Same problem on the Mac. This init method causes the following error: Multiple markers at this line
overrides acm.program.Program.init
Cannot override the final method from
Program
public void init() {
canvas = new HangmanCanvas();
add(canvas);
}
Does it have to be this hard or am I missing something?

Answer 1

Generally Macs have the whole JDK installed. Eclipse is nice, though.
This "acm" package isn't installed because it's not any kind of standard thing; this is like asking why your refrigerator doesn't come with asparagus already in it.
That last dialog was the right one; you need the original jar file. Try again, right-click and "Save As..." the link to save the file from your browser.
See 3. I find it particularly funny that anybody would use a Windows computer to make up for shortcomings of a Mac; in reality the Mac is infinitely more flexible and more powerful.
If you got a message that complains you're trying to override a final method, then you are indeed trying to do something wrong; final actually means "You're not allowed to override this." Perhaps you didn't fully understand the instructions for the assignment.
It gets better, I promise. Just be sure to use each of these annoyances as a learning experience.

Answer 2

There is no reasons why Java for the Mac would be any better than Java for the PC. The language and tools should work the same ... assuming that you are using the same versions of the language and similar versions of the tools.
Your problem with init is nothing to do with PCs versus Macs. So don't waste your time switching platforms to try to fix it. You need to figure out what the
On the face of is, the compiler / IDE is telling you the truth. Java won't let you override a final method. In fact the whole point of declaring a method to be final is to prevent overloading.
However, this does not make sense. According to the documentation I found here, the acm.program.Program.init() method is designed to be overridden. So why won't it let you?
I suspect that the cause of your problems is that you've downloaded or been given a copy of the JAR file that someone has messed around with. Someone has changes the method to be final (for some reason best kown to themselves), compiled it and put it up for people to download. Google is not always your friend ...
So, what I suggest you do is review all of the handouts and the files that were provided to find either the copy of the JAR that is provided, or the instructions on WHERE to download it from. Then replace the copy of the JAR you are currently using with the recommended one.
Why this isn’t already done for me, as part of Eclipse I have no clue. I guess everything has to be difficult.
How is Eclipse supposed to know what this "acm" stuff is? Which version you require? Where to download it from?