Java Studio by Example - Brossura

Weaver, Lynn; Robertson, Leslie

Brossura

ISBN 10: 0138995192 ISBN 13: 9780138995195

Casa editrice: Pearson P T R, 1998

Riassunto

If you want to create Web and intranet pages with the power of Java - but you're not a programmer - this book shows you how. It provides end-to-end coverage of the leading Java development tool for non-programmers, Sun's revolutionary Java Studio. The book begins with a brief tour of the main features of Java studio, using extensive examples. Learn how to choose, use and customize applets; edit Web pages; insert applets on a page; maintain your work in projects; and publish your work on the Web. The heart of the book is a set of example scenarios that show how to use Java Studio for many purposes, including creating dynamic Web pages, pages that allow interaction with users, and pages that access and display data. Virtually every Web author will find a scenario that applies to their work-and code that can save them time. The book ends with a reference section describing each Java Studio component, showing how to add components from other vendors, and explaining where to find out more.

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Recensione

Java Studio 1.0 gets a rave review in Visual Developer Magazine's 50th
Anniversary issue!
"The Future of Programming - Sun's Java Studio 1.0 by
Jennifer Atkinson"
Some pundit quoted on Sun's Web site modified Sun's tagline for Java
and described Java Studio as: "Write once, by anyone, run anywhere."
That doesn't quite encapsulate the idea. Yes, it's easy, but the
product is designed so that the simplicity engenders an elegance in
your design that you will appreciate. It does exactly what a tool is
supposed to do. You use it to build things, and the tool doesn't get
in the way.
Java Studio helps you visually build JavaBeans-based designs and
generate Java applets, Java applications, Java beans, or packaged
designs. Generating a packaged design allows you to take a
particularly useful design and add it to Java Studio's tool palette.
When you generate a Java applet, Java Studio creates an HTML file that
you can either reference from your Web page or that you can copy the
contents of into you Web page source. Java Studio also thoughtfully
generates a ZIP file for browsers that recognize these
faster-downloading files. Generating a Java application creates a BAT
file for you to run. Generating a Java bean or a packaged design
creates a JAR file.
You can import beans (assuming you have all of the classes used in the
bean) from other sources and modify them, or you can import a catalog
of beans. Java Studio offers a palette of some 50 JavaBeans
components. You build designs by picking a tool from the palette,
dropping it onto the Design or GUI Window, and wiring the components
together.
INTUITIVE DESIGN AND GUI WINDOWS
In Java Studio, you work in two windows: the Design Window and the GUI
Window. The Design Window displays your design, and the GUI Window
displays how it will look to the users of the design. When you drop a
component into the Design Window, it automatically shows up in the GUI
Window as it will appear to the user. Or, you can drop it into the GUI
Window, and the corresponding image appears in the Design Window.
As soon as you drop a component into one of the windows, the component
is live and functioning. It's not just a place-holder, waiting for you
to toggle to preview mode-it's a living, breathing component. Click on
the checkbox in the GUI Window, and the checkbox toggles on or off.
When you drop a component into one of the windows, the component's
customizer dialog box appears. You use this to name the component and
specify any details about how the component works. After you place
components into your design, you specify the data flow by "wiring" the
components together. Data and logic states (true/false) can be thought
of as "signals" flowing through these wires.
Most Java Studio components appear in the Design Window with little
knobs on them. Knobs on the left-hand side are input connectors, and
knobs on the right-hand side are output connectors. Other connectors,
such as trigger or enable/disable connectors, appear on the tops of
the components. Java Studio's Text Field component displays a single
line of text. The default for the component is one input connector and
one output connector. The input connector takes text as input. When
the user presses Enter, the text is sent to the output connector. In
the customizer dialog box, you can enable (hence display) additional
connectors. For example, you can add a trigger connector that outputs
the text when a trigger signal is received. This is helpful if you
need the text sent to the output connector even if the user doesn't
press Return.
To connect an output connector to an input connector, you click on the
output connector and drag it to the input connector. As you drag, a
line appears. If the line is green, then you are making a valid
connection. A red line, of course, indicates an invalid connection.
Disconnecting is just as simple. Click on the endpoint of the
connection and then pull it away from the component. Or, right-click
on the connection and choose Disconnect. As you build your design, you
may find that the Design Window is becoming cluttered. Rearranging
components can create some, um, silly data flows. Each connection has
handles, which allow you to pull the connections and rearrange them to
your liking. The may not seem like a big deal, but it shows that the
Java Studio designers know that their users want to control this sort
of thing in the Design Window.
JUST LIKE LEGO BLOCKS
One of the more useful features of Java Studio is its ability to
generate packaged designs. Packaged designs extend the concept of
building blocks-you can build a design, generate it as a packaged
design, and then add that design to Java Studio's tool palette.
One of the components is the External Adapter. Before you generate
packaged design, you need to add External Adapter components so that
the design has hooks for you to use to connect it to other components.
The actual act of importing other Java beans is simple, but you need
to be aware of what you are doing. For example, you need to make sure
that you have the classes referenced in the imported bean in the JAR
file. When you import a bean, Java Studio loads all of the referenced
classes early in the import process, so you'll know pretty quickly if
you are missing anything.
REAL JAVA, EASY JAVA
Java Studio used JDK 1.0.2 and JDK 1.1, but the installation process
takes care of installing the JDK for you in the Java Studio directory.
Because Java Studio is written in Java, it runs ("out of the box,"
according to Sun) on Windows 95, Windows NT 4, and Unix systems.
The documentation says that you receive a message when you add a
component that uses JDK 1.1, but I added all of the components and
never received a message. Of course, if your design uses the JDK 1.1,
you need to make sure your users are using a browser that is happy
with JDK 1.1. Note that you cannot see the source code of the beans
you are developing. Sun says that because this is a visual development
environment, you don't need to see the code. I know that this may
frustrate some programmers, but you can always generate an applet from
your design and look at the contents of the generated HTML file.
For debugging, you have a Java console window that allows you to see
the out put from a Java applet or application. The tool palette also
offers a Debug component to help when refining your designs.
On Windows 95 and NT, Java Studio needs at least 32MB of RAM.
Installed, it uses about 33MB of hard disk space, but it needs 85 MB
of free space during installation. Sun recommends running it on a
133MHz Pentium.
A PRINCE WITH SOME WARTS
As you can tell, I like Java Studio quite a bit. But, every product
has a few warts. The GUI Window doesn't seem to give any indication
when all of the GUI is not displayed. I resized the window to show
just a portion of the GUI, and when I enlarged the window again, I
couldn't tell when I had all off the GUI on display. The online help
system is fairly useful and necessary because the hard copy
documentation is pretty slim. But the help browser (it's HTML) seems
to have a few bugs. Each time I printed something from help (I know,
I'm supposed to read it online, but I like having hard copy in my
hands), words were chopped off on the right-hand side of the page.
Also, my system hung every time I canceled a print job from help.
Another nit: The search feature in this HTML-based help system only
searched the current "page," not the whole help database.
GREAT EXPECTATIONS
Java Studio is a very useful tool, especially considering that this is
release 1.0. Its intuitive, elegant design allows you to create
intuitive, elegant software. The minor rough spots shouldn't be enough
to make you forgo this product, and at $99, you don't have to.

L'autore

Lynn Weaveris Lead Technical Writer for Sun Microsystems, and co-author of Inside Java WorkShop (Prentice Hall PTR).

Leslie Robertsonis an STC-Award Winning Technical Writer.

Dettagli dell'edizione

• Editore: Pearson P T R
• Data di pubblicazione: 1998
• Lingua: Inglese
• ISBN 10: 0138995192
• ISBN 13: 9780138995195
• Rilegatura: Copertina flessibile
• Numero di pagine: 392
• Contatto del produttore: non disponibile
• Persona responsabile: Yeepin GmbH; 492000000000; sunshine12232@outlook.com; ; Alleestr.11; Kaiserslautern; Rheinland-Pfalz; 67655; Germania