In this section we will explains how you can read simple data from a database table and then use JFreeChart to create a chart of your choice.
Business Data
Consider we have the following MySQL table mobile_tbl(mobile_brand VARCHAR(100) NOT NULL, unit_sale INT NO NULL);
Consider this table is having the following records −
| Mobile Brands | Unit Sales |
|---|---|
| IPhone5S | 20 |
| Samsung Grand | 20 |
| MotoG | 40 |
| Nokia Lumia | 10 |
Chart Generation Using Database
Following is the code to create a Pie Chart based on the information provided in mobile_tbl table available in test_db in a MySQL database. Based on your requirements, you can use any other database.
import java.io.*;
import java.sql.*;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;
public class PieChart_DB {
public static void main( String[ ] args )throws Exception {
String mobilebrands[] = {
"IPhone 5s",
"SamSung Grand",
"MotoG",
"Nokia Lumia"
};
/* Create MySQL Database Connection */
Class.forName( "com.mysql.jdbc.Driver" );
Connection connect = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/jf_testdb" ,
"root",
"root123");
Statement statement = connect.createStatement( );
ResultSet resultSet = statement.executeQuery("select * from mobile_data" );
DefaultPieDataset dataset = new DefaultPieDataset( );
while( resultSet.next( ) ) {
dataset.setValue(
resultSet.getString( "mobile_brand" ) ,
Double.parseDouble( resultSet.getString( "unit_sale" )));
}
JFreeChart chart = ChartFactory.createPieChart(
"Mobile Sales", // chart title
dataset, // data
true, // include legend
true,
false );
int width = 560; /* Width of the image */
int height = 370; /* Height of the image */
File pieChart = new File( "Pie_Chart.jpeg" );
ChartUtilities.saveChartAsJPEG( pieChart , chart , width , height );
}
}
Let us keep the above Java code in PieChart_DB.java file, and then compile and run it from the command prompted as −
$javac PieChart_DB.java $java PieChart_DB
If everything is fine, it will compile and run to create a JPEG image file named Pie_Chart.jpeg having the following chart.
