Java in a Nutshell
Examples

From "Java in a Nutshell," by David Flanagan. (c) 1996 O'Reilly & Associates, Inc.

You may also download the complete set of examples as a zip file or as a compressed tar file or as a gzipped tar file. Note that a number of the examples here, particularly those in Section 5, do not stand alone--they rely on other examples from the book or on images from subdirectories. Thus, if you want to experiment with the examples, I recommend that you download the entire distribution by ftp, rather than downloading the examples one at a time through your Web browser.

A Note on Bugs and Portability

The Examples

David Flanagan
April 5th, 1996

Example 1-2

Example 2-3

Example 4-1

Example 4-2

Example 4-3

Example 4-4

Example 4-5

Example 4-6

Example 4-7

Example 4-8

Example 4-9

Example 4-10

Example 5-1

Example 5-2

Example 5-3

Example 5-4

Example 5-5

Example 5-6

• On Java ports that are still based on the JDK beta 1 release, certain Scrollbar methods aren't defined, and this example won't compile or run correctly.
• One user (Scott Gartner) of Symantec Cafe on a Windows platform has reported that he has had to change the code of this example to get it to work correctly. You can download his version below. The problem seems to have to do with the coordinate system in which mouse events are reported.

Example 5-7

Example 6-1

Example 6-2

Example 6-3

Example 6-4

Example 6-5

Example 6-6

Example 7-1

This example also contains a fetchimage() method that uses URL.getContent() to download images in GIF and other common file formats. You can use the separate FetchImageTest class to demonstrate the use of the fetchimage() method.

These plain text and image fetching examples rely on "content handlers" internal to the Java implementation. They work on JDK systems, but may not work on other Java implementations, if those implementations do not include the appropriate content handlers. If you attempt to download a file with an unsupported content type, the example will generate an exception and exit.

Note that this example is intended only to demonstrate the use of URL.getContent(). In general, this is not the best way to load text or image files over the net. See Applet.getImage(), for example.
view source code
view source code for the FetchImageTest class that demonstrates image fetching

Example 7-2

Example 7-3

Example 7-4

Example 7-5

Example 7-6

Example 7-7

A number of people have reported having trouble getting this example to work, and I have not been able to diagnose the problem. The applet does at least work with the Linux port of the 1.0.1 JDK, when both the server and applet are running on the local machine. If this applet does not work for you, it may be that your Java implementation is at fault. Networking is one of the areas in which Java is not yet as portable as it should be.
view source code

Example 8-1

Example 8-2

Example 8-3

Example 9-1

Example 9-2

Example 9-3

Example 9-4