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Problems with Applets
First, consider this information about browsers
•= If you are using Internet Explorer you need to explicitly enable it to run Java applets.
To do this, select the Options Dialog with View|Options. Then select the Security tab
and check the "Enable Java programs" box.
•= If you are using Netscape Communicator output written to the System.out character
stream is displayed in the Java Console. You can use this to display simple tracing
messages. The Console is displayed by selecting Communicator|Java Console. If you
select the console window and type an 'h' character, the console will display a set of
single-character commands that you can use to dump memory and display threads.
•= Netscape and Internet Explorer use different implementations of Java and this can
cause problems with the appearance of your applet and programming errors that
derive from the lack of support for the most recent Java features. You need to check
Netscape and Microsoft web sites for the most recent information on their respective
Java implementations.
The following checklist summarizes the points made in Chapter 2 in the section entitled
Applet Client Connection:
•= If Parallel Crystal is not running on the same machine as your Web Server, you need
to run the IIOP GateKeeper as a "proxy server" on the Web Server. The GateKeeper
forwards IIOP requests across the network to the Report Server and returns the
replies. Check with your System Administrator that the GateKeeper is running.
•= The GateKeeper can also be used as a simple Web Server. However it normally runs
on port 15000 so if the Web Server host is www.acme.com, you should connect to the
GateKeeper with a URL of the form
http://www.acme.com:15000/MyApplets/monthly.html
•= Applet class files are normally downloaded from the same directory as the HTML
page, and this directory is normally located relative to the Web Server root directory.
Make sure you know what the root directory is and that your applet class file is indeed
located where you think it should be.
•= If you store applet class files in a different directory to the HTML files, then you need
to specify a codebase attribute in the <applet> tag which specifies that directory
relative to the Web Server root.
Parallel Crystal Developer's Manual
Version 2.4 - Revised 5/27/00
112