graph generation using jfreechart and retrieving values from the database

I have made a database containing 4 subject marks and name and roll no. of students.The dsn name is chartdsn. I want to retrieve the data from the access database using prepared statement and then display the bar graph using jfreechart API .This whole retrieval and display of chart is to be done in a servlet..

Note that it is a access made database.

How can I proceed ..Pls answer.Its very urgent.

I got this answer but i need to know the meaning of this line JDBCCategoryDataset dataset=new JDBCCategoryDataset("jdbc:odbc:student", "sun.jdbc.odbc.JdbcOdbcDriver","root","root");

what is student here and how the data is being retrieved. The answer given is below.. Answer:

Follow these steps:

1)Go to the start->Control Panel->Administrative Tools-> data sources.

2)Click Add button and select the driver Microsoft Access Driver(*.mdb).

3)After selecting the driver, click finish button.

4)Then give Data Source Name and click ok button. er 5)Your DSN will get created.

6) Restart your tomcat server and run your jsp code.

<%@ page import="java.sql.*" %>
<%@ page import="java.io.*" %>
<%@ page import="org.jfree.chart.ChartFactory" %>
<%@ page import="org.jfree.chart.ChartUtilities" %>
<%@ page import="org.jfree.chart.JFreeChart" %>
<%@ page import="org.jfree.chart.plot.PlotOrientation"%>
<%@ page import="org.jfree.data.*" %>
<%@ page import="org.jfree.data.jdbc.JDBCCategoryDataset"%>

<%
String query="SELECT * from chart";
JDBCCategoryDataset dataset=new JDBCCategoryDataset("jdbc:odbc:student",
"sun.jdbc.odbc.JdbcOdbcDriver","root","root");

dataset.executeQuery(query);
JFreeChart chart = ChartFactory .createBarChart3D(
"Test", 
"Id", 
"Score", 
dataset, 
PlotOrientation.VERTICAL,true, true, false);
try
{
ChartUtilities.saveChartAsJPEG(new File("C:/chart.jpg"), chart, 400, 300);
}
catch (IOException e){
System.out.println("Problem in creating chart.");
}
%>

please reply its very urgent..how to do it.

November 9, 2011 at 11:40 AM

student is our dsn name and as far as JDBCCategoryDataset is being concern, it is a class provided by JFreechart. This class provides the implementation over a database JDBC result set. Its constructor consists of url, driver, user, pass to connect to the database. The dataset is populated via a call to executeQuery(String) with the string SQL query.