package charts;

import java.awt.Color;
import java.awt.Font;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpSession;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.DateTickMarkPosition;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYBarRenderer;
import org.jfree.chart.servlet.ServletUtilities;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.time.Year;
import org.jfree.data.xy.IntervalXYDataset;
public class BarChart
{
	 /**
     * 构造报表的结果集
     * @return
     */
    private static IntervalXYDataset createDataset()
    {
        TimeSeriesCollection dataset = new TimeSeriesCollection();
        TimeSeries series = new TimeSeries("融资量",Year.class);
        series.add(new Year(2004), 5000);
        series.add(new Year(2005), 2000);
        series.add(new Year(2006), 2200);
        series.add(new Year(2007), 3200);
        series.add(new Year(2008), 4800);
        series.add(new Year(2009), 5800);
        series.add(new Year(2010), 12000);
        series.add(new Year(2011), 14000);
        series.add(new Year(2012), 18000);
        series.add(new Year(2013), 22000);
        dataset.addSeries(series);
        return dataset;
    }
    /**
     * 根据结果集构造JFreechart报表对象
     * @param xyDataSet
     * @return
     */
    private static JFreeChart createChart(IntervalXYDataset xyDataSet)
    {
        JFreeChart jfreechart = ChartFactory.createXYBarChart(
                "历年金融债的发债融资量",         //报表标题
                "年",                         //x轴标签 
                true,                         //是否显示日期 
                "数额/亿元",                    //y轴标签 
                xyDataSet,                    //数据集 
                PlotOrientation.VERTICAL,     //柱状图的方向 
                true,                         //是否显示图例
                false,                        //是否有工具条提示
                false                         //是否有链接
                );
        jfreechart.setBackgroundPaint(Color.white);
        jfreechart.addSubtitle(new TextTitle("------《2014年银行业行业报告》",
                new Font("Dialog", Font.ITALIC, 10)));//副标题
        
        XYPlot plot = (XYPlot) jfreechart.getPlot();  //Plot 对象的获取操作
        XYBarRenderer renderer = (XYBarRenderer) plot.getRenderer();
        renderer.setMargin(0.50);
        
        DateAxis axis = (DateAxis) plot.getDomainAxis();
        axis.setTickMarkPosition(DateTickMarkPosition.MIDDLE);
        axis.setLowerMargin(0.01);
        axis.setUpperMargin(0.01);
        
        return jfreechart;
    }
    /**
     * 生成二维柱状图的图片，返回图片文件的名称
     * @param session
     * @param pw
     * @return
     */
    public static String generateBarChart(HttpSession session, PrintWriter pw)
    {
        String filename = null;
        IntervalXYDataset xyDataset = createDataset();
        JFreeChart chart = createChart(xyDataset);
        ChartRenderingInfo info = new ChartRenderingInfo(
                new StandardEntityCollection());
        try
        {
            filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info,
                    session);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        try
        {
            ChartUtilities.writeImageMap(pw, filename, info, false);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        pw.flush();
        return filename;
    }
}