• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

How can I paint a chart in the jsp

 
Ning Du
Greenhorn
Posts: 11
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I want to paint a chart in the .jsp file using the data got from DataBase.
How can I do that?
 
Ning Du
Greenhorn
Posts: 11
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
When I make a binary file using servlet,the content of HTML cannot be displayed.What should I do? Applet?
[ August 16, 2003: Message edited by: Adu Ning ]
 
William Brogden
Author and all-around good cowpoke
Rancher
Posts: 13058
6
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Think about how a HTML page containing an image is built. Each chart or other image must be the result of a separate IMG tag that you write in your JSP. The SRC= attribute in the IMG tag should point to a servlet that can generate the binary image data.
You can't use a JSP to generate typical image files because a JSP is designed to output text, not binary image data. There have been a number of discussions of this here. Any book on servlets will tell you how this is done.
Bill
 
Ning Du
Greenhorn
Posts: 11
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
William,thank you for your reply.Someone told me img=attribute tag poits to a .dll file can also solve the question.right?
 
Ron Newman
Ranch Hand
Posts: 1056
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I don't understand what you mean by that.
 
Chuck Kulchar
Greenhorn
Posts: 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have my <img ...> tag point to a servlet which gets a chart using JFree chart (jfree.org), then uses a class included in the Jfree stuff that will display the image with the OutputStream. Display line is something like:
ChartUtilities.writeChartAsJPEG(out,chart,820,380);
 
William Brogden
Author and all-around good cowpoke
Rancher
Posts: 13058
6
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
William,thank you for your reply.Someone told me img=attribute tag poits to a .dll file can also solve the question.right?

The IMG tag in HTML requires a SRC="URL" - the url is used to load the image data. That could be the URL of a servlet plus parameters that might include the name of a dll that is somehow involved. What image source do you want to use?
Bill
 
Ron Newman
Ranch Hand
Posts: 1056
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
What is a "dll" ?
 
Ning Du
Greenhorn
Posts: 11
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Something like :<IMG height="268" border="0" width="323" SRC="http://202.108.253.131:8080/wwwhq.dll?srv=401&...">
 
Bear Bibeault
Author and ninkuma
Marshal
Pie
Posts: 64717
86
IntelliJ IDE Java jQuery Mac Mac OS X
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I believe that a DLL can be used if it implements the ISAPI interface. This of course ties one into the Microsoft platform. Not a great idea, imho.
bear
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic