Apple WebObjects 5 - Manual (Page 70)

70 When To Choose Java Client
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Apple Computer, Inc. January 2002
C H A P T E R 6
WebObjects Desktop Applications
In WebObjects 5.1, the Java Client Class Loader eases applet deployment and
improves usability. Likewise, future enhancements to the JDK such as Java Web
Start will ease application deployment and usability by providing caching and
other mechanisms to ease client-side class management.
In deciding to use Java Client, you should evaluate the technology with these
criteria in mind: portability, performance, network environment, administration,
security, and user experience.
■ Portability: Java Client applications are 100% Pure Java applications, requiring
a JRE 1.3 or higher system. Java Client applications running on Mac OS X take
advantage of platform-specific interface features such as the global menu and
the dirty window marker.
■ Performance: After the initial download of Java classes to the client, Java Client
applications don’t exchange large chunks of data between client and server.
Rather, compact business objects are exchanged over the network. Also, the Java
Client architecture separates the user interface layer from the data exchange
layer, so data flows across the network independent of user interface data. This
allows Java Client applications to scale well, and a WebObjects application
server should scale just as well serving Java Client applications or HTML-based
applications.
■ Network environment: Java Client applications can be deployed across the
Internet; they are not inherently constrained to intranet environments.
However, they are not appropriate for high-volume, high-visibility applications
because of the long initial download and other system administration
requirements (presence of JRE 1.3 or higher).
■ System administration: The presence of JRE 1.3 or higher is not ubiquitous
amongst desktop operating systems. Mac OS X includes JRE 1.3 out-of-the-box;
JRE 1.3 is not available for Mac OS 9 or earlier; Sun provides the JRE for all
Windows platforms, but it does not ship in the box; JRE 1.3 is available for many
UNIX platforms. So, while the JRE is widely available, it must often be
downloaded and installed by the end user. You should evaluate your target
market, keeping in mind that some customers will be put off by the proposition
of installing the JRE.
■ Security: If you take careful steps to partition your business logic, Java Client
applications offer security equal to that of HTML-based applications. By default,
Java Client uses HTTP as the transport protocol between client and server, but it
can be replaced with another, more secure protocol such as SSL.