TweetFollow Us on Twitter

May 96 Factory Floor
Volume Number:12
Issue Number:5
Column Tag:From The Factory Floor

Discover Java

By Dave Mark

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

This month, the big news from Metrowerks is the release of their long-awaited Java development environment, timed to coincide with the start of WWDC. Metrowerks’ version of Java comes in two flavors. If you already subscribe to CodeWarrior Gold, have no fear, the complete set of Java tools is included with the just released CW9. The complete Java toolset will also be packaged without all the C, C++, and Pascal tools under the name Discover Programming with Java.

I had a chance to speak with some of the engineers behind Metrowerks’ Java effort. Without further ado, here’s my conversation with Marcus Jager, Clint Popetz, Peter N Lewis, Tim Freehill, and Mike Lockwood...

Dave: Let’s start off by talking about CodeWarrior. Can you explain the process of building, compiling, and running a Java project?

Marcus: Our primary goal with supporting Java on the Macintosh was to make the experience as Mac-like as possible. This means that we had to remove from Java the over-dependence on file system hierarchy and environment variables. The user shouldn’t have to do anything more than add a pile of Java source files to a project and hit Command-R.

Peter: We tried to make working with Java almost exactly the same as any other CodeWarrior target. So you make a new project (using a Java stationery document, or just select Java as the target). Then drag in your Java source files, and any zip files you need (you can weak link these if you know they will be available). Like the other targets, you use the Java project panel and select the type of output and other options. Then you can debug your program using the same source level debugger that CodeWarriors are used to.

Tim: Java has really fit smoothly into the IDE. The language-specific features were altered to support Java, so now you have Java keyword highlighting, and Java methods are parsed for the function popup. But using CodeWarrior to program Java really is not much different from using CodeWarrior to program C++.

Dave: What is the difference between an applet and an application? What does a Java application look like on the Mac?

Marcus: This is where something like Java causes terminal confusion in the naming of things. For the record: An applet is just a sub-class of the applet Java class, nothing special. Applet objects are what Web browsers use to embed Java code in web pages; this is what most people mean when they talk about Java. A Java application is a complete self-contained program that runs independently from the network and Web browsers. Currently these are executed in the standalone Java interpreter application, but there are better ways of doing this.

Clint: An applet can only be viewed within an “applet context”. This context can be provided by a browser like Netscape, or a simple program like the AppletViewer. Applets are intended to be embedded in HTML pages. Since they are meant for dispersion via the internet, they are placed under pretty strong security restrictions with respect to disk access, loading native code, or accessing the network.

Peter: Using CodeWarrior you can build several other kinds of outputs. My favorite is a Macintosh droplet - this is just a tiny 68K application that asks the Java interpreter to execute the zip file stored in its data fork. If your target is a droplet then you can just choose Run from the Project menu, the project will be brought up to date and your code will be executed in the interpreter. If you add a BNDL resource you can then drag and drop files onto your droplet. Also, you may be able to include some native shared libraries and then use native classes to do processor-intensive or hardware-specific Mac-only solutions. So, for example, you might write some C code to interface to a scanner, package it up as a Java class and a shared library, and then do all the rest of the code using Java, perhaps using AWT as the interface, or writing some more native Mac code. I think this is going to be a lot of fun.

Dave: The standard user interface in the Java universe is defined by AWT (the advanced windowing toolkit). The AWT interface is definitely different than the standard Mac interface. For example, under AWT, each window has its own menubar. How is AWT implemented on the Mac?

Clint: Well, I mapped the AWT components onto PowerPlant LPane subclasses. So AWT buttons look like LStdButtons, etc. Since each AWT Frame (window) can have its own set of menus, I have each window put its menus in the bar when activated, and pull them out when deactivated. A bigger problem is that there is no equivalent of the Mac Human Interface Guidelines for the AWT; you can make your “OK” button say “Yessir,” put it in the top left corner of the window, make it mauve, and make its font italic. And since many people writing Java code will not be used to the Mac, you can expect a lot of weird-looking Mac windows.

Dave: Do you think we’ll ever see a mainstream Macintosh application written in Java? Perhaps based on a more Mac-like AWT with its own version of Constructor?

Marcus: Time for some marketing speak: “Metrowerks considers these to be important future directions.” Java has opened up a world of possibilities, and it will be a while before it’s clear what its true strengths will be. I think that Java is much more than the Internet and the Web. I would love to see mainstream Macintosh applications written in Java. I think the very strong type safety and automatic garbage collection would be a big step forward in programming practice and lead to better quality programs.

Dave: Can you call C code from inside a Java applet? If so, what is the binding mechanism that makes this possible? What security implications does this have?

Clint: Applets can use native C code, but only if it is has already been loaded by the Java virtual machine. So the virtual machine decides what native code is safe (like the native code that implements the AWT), and the applets can use this.

Marcus: The Java virtual machine calls C code from Java by linking to a shared library and calling the C functions contained in it. Since the virtual machine has no way of verifying what the shared library does, it relies on the user to install only libraries that they know are safe, and provides no automatic system for downloading them.

Dave: What impact will mixing Java and C/C++ have on my ability to debug my programs?

Mike: The CodeWarrior debugger will support debugging both C/C++ code and Java code simultaneously. The CW8 debugger can already debug 68K and PowerPC code simultaneously, and in CW9 we are adding Java support as a third target. You will be able to single-step through both C++ and Java code, display C++ and Java objects, and see both Java and C stack frames in the stack crawl window, all at the same time.

Dave: How will Java affect the world of web site management? Will CGI/Perl programming go away?

Marcus: One of the problems that people are starting to realize about Java is that you still need professional programmers to write applets. All Java does is increase the maximum power of expression available to web page creators; it does not make their task easier. JavaScript will likely have a greater impact on the use of CGI/Perl than Java. Also, web site management needs more powerful but simple-to-use tools. Adobe PageMill is a step in this direction, but there is a long way to go.

Clint: Perl programming will never go away. But the use of CGI/Perl solutions in web pages may dwindle as applets become easier to write, and as standard suites of applets become available to web page authors.

Dave: What is “just in time” compilation? Does Metrowerks support it?

Clint: JIT is on-the-fly compilation of Java bytecodes to native instructions, providing an enormous speed jump while not breaking the platform-neutrality of the binary. Our VM has hooks in it in order to support this.

Marcus: Marketing speak again: “Improving the execution speed of Java is an important future direction.” Obviously, the success of Java depends a great deal on its speed. The faster the interpreter, the more powerful and complex the programs that can be written.

Dave: How would you compare Java to other object programming languages you’ve worked with?

Tim: Because they’ve ripped out a lot of the “features” of C++ that cause problems, like pointers and direct memory manipulation, and have added features to make the programmer’s life easier, like automatic garbage collection, I can see Java becoming a very popular development language. In any development, how many crashing bugs are the result of writing to the wrong piece of memory? That won’t happen in Java: a big headache is gone. In addition, Java code is more readable and maintainable than most C++ code, because Java was written from the ground up as an object-oriented language, and has no feature compatibility to maintain with a cryptic language like C. All of the stuff that shouldn’t be there isn’t. The resulting code is clean and well organized, because Java pretty much has to be written that way. So bring on the Java-heads!

Clint: Java is a much cleaner language than C++, as it eliminates unsafe constructs like pointers, and provides automatic storage reclamation. It is statically typed (like C++), but is dynamically linked and loaded (like Smalltalk), thus providing for a much more loosely coupled language, which lends itself to a faster prototyping cycle. It has a whole slew of cool features, including typed exceptions and synchronization primitives. It also has a pretty complete set of language libraries. On the downside, Java does not support parametric polymorphism, and it does not provide for multiple inheritance of implementation. Overall, I consider it to be a very cool language that collects the better parts of a lot of existing languages. The best point in Java’s favor is that it is designed to be a production language. And we’re doing our best to help Mac programmers produce with it.

Marcus: I think Java has the right features for success. Its greatest trick is that on the surface it looks like C/C++, but is in fact a well designed object-oriented programming language. This means that all those C/C++ programmers out there who are biased against a properly designed language will use it because it seems to be a C++ derivative. Not used to looking deeply at the languages they use, they will be lured by the syntactic sugar of Java; beguiled by the surface similarities, they will become seduced by the garbage collection and type safety. Finally the world may start to use a “real” programming language and we can leave the dark ages behind.

 
AAPL
$517.96
Apple Inc.
+0.00
MSFT
$39.75
Microsoft Corpora
+0.00
GOOG
$536.44
Google Inc.
+0.00

MacTech Search:
Community Search:

Software Updates via MacUpdate

Starcraft II: Wings of Liberty 1.1.1.180...
Download the patch by launching the Starcraft II game and downloading it through the Battle.net connection within the app. Starcraft II: Wings of Liberty is a strategy game played in real-time. You... Read more
Sibelius 7.5.0 - Music notation solution...
Sibelius is the world's best-selling music notation software for Mac. It is as intuitive to use as a pen, yet so powerful that it does most things in less than the blink of an eye. The demo includes... Read more
Typinator 5.9 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
MYStuff Pro 2.0.16 - Create inventories...
MYStuff Pro is the most flexible way to create detail-rich inventories for your home or small business. Add items to MYStuff by dragging and dropping existing information, uploading new images, or... Read more
TurboTax 2013.r17.002 - Manage your 2013...
TurboTax guides you through your tax return step by step, does all the calculations, and checks your return for errors and overlooked deductions. It lets you file your return electronically to get... Read more
TrailRunner 3.8.769 - Route planning for...
Note: While the software is classified as freeware, it is actually donationware. Please consider making a donation to help support development. TrailRunner is the perfect companion for runners,... Read more
Flavours 1.1.10 - Create and apply theme...
Flavours is a Mac application that allow users to create, apply and share beautifully designed themes. Classy Give your Mac a gorgeous new look by applying delicious themes! Easy Unleash your... Read more
Spotify 0.9.8.296. - Stream music, creat...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue... Read more
SlingPlayer Plugin 3.3.20.475 - Browser...
SlingPlayer is the screen interface software that works hand-in-hand with the hardware inside the Slingbox to make your TV viewing experience just like that at home. It features an array of... Read more
S.M.A.R.T. for USB and FireWire Drives 0...
S.M.A.R.T. for USB and FireWire Drives is a kernel driver for OS X external usb or firewire drives. It extends the standard driver behaviour by providing access to drive smart data. The interface to... Read more

Latest Forum Discussions

See All

RollerCoaster Tycoon 4 Mobile Review
RollerCoaster Tycoon 4 Mobile Review By Jennifer Allen on April 16th, 2014 Our Rating: :: DISAPPOINTINGLY WEAKUniversal App - Designed for iPhone and iPad The RollerCoaster Tycoon franchise finally comes to iOS, but it’s a rather... | Read more »
148Apps Live on Twitch: Pivvot’s Looper...
On our latest Twitch stream, we’ll be playing a pair of minimalist arcade games, one that just got a big content update in Pivvot, and another that was inspired by it in 15 Coins. Whitaker Trebella, creator of Pivvot, will discuss the new modes... | Read more »
Word Cubes Review
Word Cubes Review By Jordan Minor on April 15th, 2014 Our Rating: :: SQUARESVILLEUniversal App - Designed for iPhone and iPad Word Cubes is fine, but it is barely any different from any other word game.   | Read more »
PAX East 2014 – Desert Fox: The Battle o...
PAX East 2014 – Desert Fox: The Battle of El Alamein is Coming to iOS Soon Posted by Rob Rich on April 15th, 2014 [ permalink ] Shenandoah Studio has become one of the go-to developers for war games on iOS, with | Read more »
Tank of Tanks Review
Tank of Tanks Review By Carter Dotson on April 15th, 2014 Our Rating: :: TANKS A LOT!iPad Only App - Designed for the iPad This multiplayer game played on a single iPad is simple, chaotic fun.   | Read more »
PAX East 2014 – Dungeon of the Endless J...
PAX East 2014 – Dungeon of the Endless Just Might Have a Shot at an iPad Release Posted by Rob Rich on April 15th, 2014 [ permalink ] I think it’s fair to say that | Read more »
SideSwype Review
SideSwype Review By Carter Dotson on April 15th, 2014 Our Rating: :: ON YOUR SIDEUniversal App - Designed for iPhone and iPad SideSwype is a puzzler that takes inspiration from Threes, but becomes its own incredibly fun game.   | Read more »
PAX East 2014 – Bigfoot Hunter Invites P...
PAX East 2014 – Bigfoot Hunter Invites Players on a Wild and Wooly Photo Safari Posted by Rob Rich on April 15th, 2014 [ permalink ] Yeti. Sasquatch. Wendigo. | Read more »
Dungeon Quest Review
Dungeon Quest Review By Cata Modorcea on April 15th, 2014 Our Rating: :: NO STORY, BUT GOOD FUNUniversal App - Designed for iPhone and iPad Dungeon Quest does a lot of things right, but ultimately forgets about one of the core... | Read more »
Tempo AI and Speek Join Forces to “Kill...
Tempo AI and Speek Join Forces to “Kill the Conference Call PIN” Posted by Rob Rich on April 15th, 2014 [ permalink ] Today Tempo AI, makers of Tempo Smart Calendar, and | Read more »

Price Scanner via MacPrices.net

Download our app, iTracx, for iOS and Android
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
Education discounts shave up to $300 off the...
Purchase a new Mac at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and all... Read more
Save $50 on Mac mini Server
B&H Photo has the 2012 Mac mini Server on sale for $949 including free shipping plus NY sales tax only. Their price is $50 off MSRP. Read more
PhatWare’s “Ultimate Writing App For iOS” Ren...
PhatWare Corp. has announced it has renamed its new WritePro word processing app for iPhone and iPad: WritePad Pro. The decision to change the app’s name to leverages the strong brand awareness and... Read more
Full Resolution Photo Editor Tint Mint 1.0 Re...
California based independent developer, Jeffrey Sun, creator of the iOS app Modern Editor, has released Tint Mint, a new photography app for editing enthusiasts. The app costs a dollar, and it packs... Read more
16GB iPad mini (Apple refurbished) available...
The Apple Store has refurbished 1st generation 16GB iPad minis available for $249 including free shipping. Both black and white models are available. Read more
Save $120 on the 27-inch 3.2GHz Haswell iMac
B&H Photo has the 27″ 3.2GHz iMac on sale for $1679.99 including free shipping plus NY sales tax only. Their price is about $120 off MSRP. Read more
Using a Mac Doesn’t Eliminate The Heartbleed...
Low End Mac’s Dan Knight notes that any time you visit a website with an https: prefix or see that secure lock icon on your browser, some type of security software is busy trying to protect your data... Read more
AirPrint Basics Tutorial Posted
A new Apple Knowledge Base article helps get you started using AirPrint, the Apple protocol that enables instant printing from iPad, iPhone, iPod touch, and Mac without the need to install drivers or... Read more
Speed Tips For Running LibreOffice On The Mac
LibreOffice is my favorite of several free, open-source application suites, and the one I have configured on my Mac as my default app for Word documents that one frequently has to deal with. It also... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Retail - Market Leader - Cincinnati...
…challenges of developing individuals, building teams, and affecting growth across Apple Stores. You demonstrate successful leadership ability - focusing on excellence Read more
*Apple* Retail - Manager - SoHo - Apple (Uni...
Job SummaryKeeping an Apple Store thriving requires a diverse set of leadership skills, and as a Manager, you're a master of them all. In the store's fast-paced, dynamic Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** Every day, business customers come to the Apple Store to discover what powerful, easy-to-use Apple products can do for them. As a Business Leader, Read more
Position Opening at *Apple* - Apple (United...
…challenges of developing individuals, building teams, and affecting growth across Apple Stores. You demonstrate successful leadership ability - focusing on excellence Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.