Here are some simple instructions to get you going in writing Java
code in CodeWarrior. They do not cover using the debugger. More
detailed references are cited at the end.
After launching Metrowerks IDE (Integrated Development Environment),
select New Project under the file menu.
In the dialog box that appears, select "CSCI136Application" and click OK.
When the next dialog box pops up, navigate to where you wish to save your
program and then type the name of your project. It is generally best to select
the name of the main class of your program and add ".mcp". For example a
program whose main class is named "Test" will have a project named Test.mcp.
(Note that the "mcp" is only there to be compatible with Metrowerks on
Windows.)
At this point the computer will create a folder with the name of your main
class (e.g., "Test" if you typed "Test.mcp" in the previous step). In the
folder will be the project file (Test.mcp), a program file named
TrivialApplication.java, and a folder whose name is obtained by appending
"data" to the end of the project name (e.g., "Test.mcp data"). Don't touch
anything in the data folder.
A project window will pop up. It contains directories "Sources" and
"Classes". Click on the triangle to the left of the directory names to see
their contents. "TrivialApplication.java" will be in Sources while
"classes.zip" and "structure.zip" will be in Classes. As you might expect,
the first folder holds
your source code, while the second contains pre-compiled packages. The package
classes.zip includes classes necessary to run all Java programs, while
structure.zip contains all of the classes from Bailey's structure
library.
Double click on TrivialApplication.java. Change the class name to the name
of your main class (e.g., "Test"). Under file menu, select "save as" and
save as "Test.java". Note be careful to save in folder Test. Unfortunately,
saving without navigating to the right folder will save it in the wrong place,
screwing you up royally when you try to run your applet. Note that when you
use "Save as" it will change the file in the project to Test.java. It is
important that your Java file name correspond to the name of the class stored
in the file. Metrowerks will usually be able to handle it if you don't do
this, but most other Java compilers will get confused. Go back to the
finder and throw away TrivialApplication.java as it is no longer needed and
simply clutters up your directory.
Unfortunately, you must change another of other items in order to get the
system straightened out. Under the Edit menu, select "Java Application
Settings". Under "Target Settings", set the "Target Name" to the name you you
wish the executable to have (usually the same name as the main class). Under
"Java Target", set the "Main Class". To be the name of the class you wish to
begin executing as the main program (e.g., "Test"). Finally, under "Linker
output", set the name of the output to be the name of your main class followed
by ".jar" (e.g., "Test.jar"). Technically, only the middle step is required
(setting "Main Class" under Java Target). The other two could be ignored or
given any other name you like, but it is convenient to change all three. Save
these settings and close the window.
Fill in appropriate code in Test.java. Don't forget to put in import
statements if you need classes from any packages (such as graphics, structures,
or java.awt). You will also need to add ".java" and either ".zip" or ".jar"
files to the project for any classes or libraries needed in your program. You
can add these to the project by either selecting Add Files from the project
menu or Add Window from the same menu if the class you wish to add is from the
topmost window on the screen.
Programs can be compiled and run using the project menu. Selecting
"compile" will compile the class in the topmost window (and any classes it
depends on). Selecting "make" will compile all classes in the project which
have been changed since their last compilation. Selecting "run" will compile
all of these classes and launch an applet viewer for running your program.
Buttons on the project window can also be used to "make" or "run" your program.
The button which looks like "writing a list" does the "make", while the "right
arrow" does the "run".
Of course, you are likely to have syntax errors when you compile Java
code. If so, a window, "Errors and Warnings", will pop up with a list of all of
your errors. The first error will be highlighted and a listing of the class
containing the error will be displayed with a red arrow pointing to the line
with the error. You can fix errors directly in this listing and those changes
will be recorded in the original file. To move to the next error, either click
once on the error or hold down the command (apple) and option keys and click on
the "[[arrowdown]]" key. If you double-click on an error message it will bring
up the original file at the point of the error. When you have fixed all of the
errors just try compiling again (the system will generally save all of the
changes you have made automatically). Much of the time you will receive
another wave of error messages to respond to. This simply reflects the fact
that the compiler got farther before giving up the compilation.
At the top of an IDE editor window holding a Java class definition is a
menu labelled "{}". If you pull this down you will see a list of all of the
methods defined in the class. Select any one to go immediately to its
definition.
When you run a Java program, the Metrowerks IDE application launches a
separate application, Metrowerks Java, to interpret your compiled program. If
you forgot to change the Java Target you may get an error message that it could
not find your main class. If this occurs, go back to the IDE, fix the Java
Target, and select Run again.
Of course there is much more to learn about using CodeWarrior. The best way to
learn about CodeWarrior is to read the on-line documentation. I liked the
Targeting Java (either QV or pdf format) and CW IDE user's guide for
MacOS
(either QV or pdf) for getting information on how to use the Metrowerks IDE,
Metrowerks Java, and the debugger. The Apple guides for Metrowerks (available
under the "?" menu when Metrowerks IDE is running) can also be quite helpful in
providing instruction on setting up projects and also have reasonable
documentation on the Java language. I recommend starting with Targeting Java
and then branching out to the other documentation.
