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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

f.lux 37.7 - Adjusts the color of your d...
f.lux makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day. Ever notice how people texting at night have that eerie blue glow? Or wake... Read more
BBEdit 11.6.1 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
ScreenFlow 6.1 - Create screen recording...
ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your entire monitor while also capturing your video camera, microphone and your... Read more
Microsoft Office 2016 15.25 - Popular pr...
Microsoft Office 2016 - Unmistakably Office, designed for Mac. The new versions of Word, Excel, PowerPoint, Outlook and OneNote provide the best of both worlds for Mac users - the familiar Office... Read more
FileZilla 3.21.0 - Fast and reliable FTP...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.21.0: Fixed Vulnerabilities Fixed a string format... Read more
Fantastical 2.2.5 - Create calendar even...
Fantastical 2 is the Mac calendar you'll actually enjoy using. Creating an event with Fantastical is quick, easy, and fun: Open Fantastical with a single click or keystroke Type in your event... Read more
The Hit List 1.1.26 - Advanced reminder...
The Hit List manages the daily chaos of your modern life. It's easy to learn - it's as easy as making lists. And it's powerful enough to let you plan, then forget, then act when the time is right.... Read more
Typinator 6.10 - Speedy and reliable tex...
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
EtreCheck 3.0.2 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
FileZilla 3.21.0 - Fast and reliable FTP...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.21.0: Fixed Vulnerabilities Fixed a string format... Read more

Ruismaker FM (Music)
Ruismaker FM 1.0 Device: iOS Universal Category: Music Price: $4.99, Version: 1.0 (iTunes) Description: Following up on the success of Ruismaker, here's her crazy twin-sister, designed for people who want to design their own... | Read more »
Space Marshals 2 (Games)
Space Marshals 2 1.0.15 Device: iOS iPhone Category: Games Price: $5.99, Version: 1.0.15 (iTunes) Description: The sci-fi wild west adventure in outer space continues with Space Marshals 2. This tactical top-down shooter puts you in... | Read more »
Dungeon Warfare (Games)
Dungeon Warfare 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: Dungeon Warfare is a challenging tower defense game where you become a dungeon lord to defend your dungeon against greedy... | Read more »
Solitairica (Games)
Solitairica 1.0.7 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0.7 (iTunes) Description: Solitairica takes RPG combat and challenging rogue-like progression to a fresh new place—the world of solitaire! | Read more »
Bowmasters tips, tricks and hints
At least for this writer, archery was one of the more pleasant surprises of the 2016 Rio Olympics. As opposed to target shooting with guns, which was dreadfully boring, watching people shoot arrows at targets was pretty darn cool. [Read more] | Read more »
Best apps for watching live TV
The Olympics have come and gone, leaving nearly everyone in a temporary state of "What the heck am I going to watch on TV right now?" Besides old reruns of Golden Girls, but that goes without saying. [Read more] | Read more »
What is Flip Diving, and why has it take...
Move over Pokemon GO. There's a new king in town, and it's "the world's #1 cliff diving game." [Read more] | Read more »
5 places where Pokemon GO is still numbe...
In the U.S., the bloom is off the Pokemon Go rose ever so slightly. It's still doing great, sitting atop the top grossing chart as it has for some time, but it's no longer among the top 10 free apps in downloads, possibly because darn near... | Read more »
Madden NFL Mobile: How defense has chang...
Saying that defense is not a priority in Madden NFL Mobile is a bit of an understatement. In asynchronous head-to-head play, you don't take control of your defenders at all, as the AI manages them while your opponent plays offense. When it's your... | Read more »
Feed Hawk (News)
Feed Hawk 1.0.1 Device: iOS Universal Category: News Price: $2.99, Version: 1.0.1 (iTunes) Description: Feed Hawk makes it easy to subscribe to the RSS feed of the website you are visiting. From within Safari, simply open a share... | Read more »

Price Scanner via MacPrices.net

Will We See A 10.5″ iPad Pro in 2017? – The ‘...
A MacRumors report, cites a research note from KGI Securities analyst Ming-Chi Kuo, saying a new size iPad model is in the works. According to the highly respected Cho, who has a strong track record... Read more
IOGEAR USB-C Docking Station Transforms Lapto...
IOGEAR has announced the launch of its innovative USB-C Docking Station with Power Delivery which turns USB-C enabled laptops into desktop workstations. The new IOGEAR USB-C Docking Station features... Read more
12-inch Retina MacBooks on sale for up to $10...
Amazon has 2016 12″ Apple Retina MacBooks on sale for $100 off MSRP. Shipping is free: - 12″ 1.1GHz Space Gray Retina MacBook: $1199 $100 off MSRP - 12″ 1.1GHz Silver Retina MacBook: $1224.99 $75 off... Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $120 off MSRP including free shipping plus NY sales tax only: - 21″ 3.1GHz iMac 4K: $1379 $120 off MSRP - 21″ 2.8GHz iMac: $1199.99 $100 off MSRP - 21″ 1... Read more
Typinator 6.10 comes with 50 improvements – G...
Ergonis Software today announced release of Typinator 6.10, a new version of their text expander utility for macOS. Typinator 6.10 comes with 50 improvements, including new features, compatibility... Read more
Taxi Sim 2016 Puts Users Behind the Wheel in...
Ovilex Soft today announces Taxi Sim 2016, an update to their ultra-realistic 3D driving simulator app for iOS and Android devices — literally a global event what with the company’s nearly 450,000... Read more
11-inch 1.6GHz/128GB MacBook Air on sale for...
Amazon has the current-generation 11″ 1.6GHz/128GB MacBook Air (sku MJVM2LL/A) on sale for $788 for a limited time. Their price is $111 off MSRP, and it’s the lowest price available for this model. Read more
Apple refurbished Mac minis available for up...
Apple has Certified Refurbished Mac minis available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $80 off MSRP - 2.6GHz Mac... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more

Jobs Board

*Apple* Retail - Multiple Positions Akron, O...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Simply Mac *Apple* Specialist- Repair Techn...
…The Technician is a master at working with our customers to diagnose and repair Apple devices in a manner that exceeds the expectations set forth by Apple Read more
*Apple* Retail - Multiple Positions Germanto...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Professional Learning Specialist - A...
# Apple Professional Learning Specialist Job Number: 51234379 Portland, Maine, Maine, United States Posted: Aug. 18, 2016 Weekly Hours: 40.00 **Job Summary** The Read more
Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 51218465 Richmond, VA, Virginia, United States Posted: Aug. 18, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.