The servlet is setup here to read the configuration data from a text file
and the graph data from a server side process, VbarDataServlet.
and here is the HTML code,
<img src="http://localhost:8080/servlet/VbarchartServlet?
config=http://www.jpowered.com/graph_chart_collection/VerticalBarGraph/Examples/barprops.txt& data=http://localhost:8080/servlet/VbarDataServlet"
width="450" height="440">
The VbarDataServlet ( click
here to view code ) is a simple servlet designed to demonstrate how a servlet can be used to return data to either the graphing
applet or servlet. As you will see the main routine ( doGet() ) uses the method GraphData() to construct the return data. Although
in this example the GraphData() routine simply builds the return data from 'hard coded' values, in practice this routine would
be expanded to first gather data from any number of data sources. eg. databases, files other server processes.
There are various methods by which the graphing servlet can be set to acquire
data from databases including:-
Direct Database Binding
Database Script Interface
For a full discussion on the various methods and example scripts please see the
Tutorial section - click here.
For a full explanation of and range of values for the above parameters please
see the Documentation - Configuration Options».
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