Hey,

Ich suche schon seit einigen tagen nach einer möglichkeit meinen Chart (jfreechart) via Button click updaten / refrechen zu lassen falls z.B neue daten in der datenbank ankommen oder falls der user mal ne andere hintergrundfarbe wählt.

Das ist mein servlet der den chart generiert :

Code :
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import org.jfree.data.jdbc.JDBCPieDataset;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
 
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.SQLException;
import java.sql.DriverManager;
import java.sql.Connection;
 
public class PieChart extends HttpServlet {
    private static final long serialVersionUID = 1L;
    
 
    public void init() throws ServletException {
        super.init();
        try {
            Class.forName("org.postgresql.Driver").newInstance();
        } catch (InstantiationException e) {
            throw new ServletException(e);
        } catch (IllegalAccessException e) {
            throw new ServletException(e);
        } catch (ClassNotFoundException e) {
            throw new ServletException(e);
        }
    }
 
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String colour = request.getParameter("colour");
 
 
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:postgresql://localhost:5432/jfreechartdb", "jfreechart", "password");
            JDBCPieDataset dataset = new JDBCPieDataset(connection);
            dataset.executeQuery("Select * From piedata1");
            JFreeChart chart = ChartFactory.createPieChart("Pie Chart", dataset, true, false, false);
                response.setContentType("image/png");
                OutputStream out = response.getOutputStream();
                ChartUtilities.writeChartAsPNG(out, chart, 450, 400);
            
        } catch (SQLException e) {
            log("Exception retrieving chart data", e);
        } finally {
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                    log("Could not close Connection", e);
                }
            }
        }
    }
}

mein Portlet soweit :

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import com.vaadin.Application;
import com.vaadin.terminal.Sizeable;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import com.vaadin.ui.MenuBar.Command;
import com.vaadin.ui.MenuBar.MenuItem;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.Label;
import com.vaadin.ui.MenuBar;
import com.vaadin.ui.Slider;
import com.vaadin.ui.Window;
import com.vaadin.ui.Button;
 
public class vaadinportlet extends Application implements ClickListener {
    
     Button Refresh;    //Refresh Button
    public Window window;       //Main Window
    Label Kiviat;       //Kiviat Chart
    Label Kuchen;       //Pie Chart
    private MenuBar menubar = new MenuBar();
    private static final long serialVersionUID = 1L;
    @SuppressWarnings("serial")
    public void init() {
        window = new Window("");
        setMainWindow(window);
        HorizontalLayout fittingLayout = new HorizontalLayout(); 
        Kiviat = new Label("<img src=http://localhost:8888/portlet/KiviatDiagramm", Label.CONTENT_XHTML);
        window.addComponent(Kiviat);
        Kuchen = new Label("<img src=http://localhost:8888/portlet/PieChart", Label.CONTENT_XHTML);
        window.addComponent(Kuchen);
        Kuchen.setVisible(false);
        fittingLayout.setWidth(Sizeable.SIZE_UNDEFINED, 0); 
        Refresh = new Button("Refresh");
        Refresh.addListener(this);
        fittingLayout.addComponent(Refresh);
        window.addComponent(fittingLayout);
        //Start menu "Config"
        final MenuBar.MenuItem config = menubar.addItem("Config", null);
        final MenuBar.MenuItem newItem = config.addItem("Select Chart Typ", null);
        config.addSeparator();
 
        newItem.addItem("PieChart", new Command(){
                public void menuSelected(MenuItem selectedItem) {
                    Kuchen.setVisible(false);
            }
        });
 
        fittingLayout.addComponent(menubar);
        //End Menu "Config"
    }
 
    public void buttonClick(ClickEvent e) {
        if(e.getSource() == Refresh){
            Refresh.setCaption("Refresh on");
 
        }
    }
    @SuppressWarnings("serial")
    private Command menuCommand = new Command() {
        public void menuSelected(MenuItem selectedItem) {
        }
    };
}


Beim klicken des "Refresh" Buttons soll der Chart neu gezeichnet werden .


Mfg

kiesa747