jfreechart生成柱状图与饼状图(入门)

/**
* 生成柱状图
*/
public String genChannelNumBarChart() {
try {
@SuppressWarnings("unchecked")
List<Object[]> lst = channelService.getArticleNumByChannel();

int lstSize = lst.size();

double[][] data = new double[lstSize][1];
String[] rowKeys = new String[lstSize];
String[] columnKeys = new String[]{""};
int i = 0;
for (Object[] obj : lst) {
log.debug(obj[0] + "," + obj[1]);

data[i] = new double[] { Double.parseDouble(String
.valueOf(obj[1])) };

rowKeys[i] = String.valueOf(obj[0]);
i++;
}

CategoryDataset dataset = DatasetUtilities.createCategoryDataset(
rowKeys, columnKeys, data);
JFreeChart chart = ChartFactory.createBarChart3D("栏目文章统计图", "栏目",
"文章数", dataset, PlotOrientation.VERTICAL, true, false,
false);

// 通用程序
TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体", Font.BOLD, 15));
CategoryPlot plot = chart.getCategoryPlot();
CategoryAxis domainAxis = plot.getDomainAxis();
domainAxis.setLabelFont(new Font("黑体", Font.BOLD, 15));
domainAxis.setTickLabelFont(new Font("黑体", Font.BOLD, 15));
ValueAxis valueAxis = plot.getRangeAxis();
valueAxis.setLabelFont(new Font("黑体", Font.BOLD, 15));
chart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 15));

String filename = ServletUtilities.saveChartAsPNG(chart, 600, 400,
null, this.getSession());
String graphURL = this.getRequest().getContextPath()
+ "/DisplayChart?filename=" + filename;

log.debug("graphURL:" + graphURL);

this.setAttribute("graphURL", graphURL);
this.setAttribute("filename", filename);

return "channelNumBarChart";

} catch (Exception e) {
e.printStackTrace();
}

return "channelNumBarChart";
}

/**
* 生成饼状图
* @return
*/
public String genChannelNumPieChart() {
try{
@SuppressWarnings("unchecked")
List<Object[]> lst = channelService.getArticleNumByChannel();
//设置数据集
DefaultPieDataset dataset = new DefaultPieDataset();

int i = 0;
for (Object[] obj : lst) {
log.debug(obj[0] + "," + obj[1]);
dataset.setValue(String.valueOf(obj[0]),
Double.parseDouble(String.valueOf(obj[1])));
i++;
}
//通过工厂类生成JFreeChart对象
JFreeChart chart = ChartFactory.createPieChart3D("栏目文章发布分布图",
dataset, true, false, false);

TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体",Font.BOLD,15));

PiePlot pieplot = (PiePlot) chart.getPlot();
pieplot.setLabelFont(new Font("宋体", 0, 12));

//没有数据的时候显示的内容
pieplot.setNoDataMessage("无数据显示");
pieplot.setCircular(false);
pieplot.setLabelGap(0.02D);

chart.getLegend().setItemFont(new Font("黑体",Font.BOLD,15));
//pieplot.getLegendItems().
//XYPlot  xyPlot=(XYPlot)chart.getPlot();
//xyPlot.getRangeAxis().setLabelFont(new Font("黑体",Font.BOLD,15));

String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300,
null, this.getSession());
String graphURL = this.getRequest().getContextPath()
+ "/DisplayChart?filename=" + filename;

this.setAttribute("graphURL", graphURL);
this.setAttribute("filename", filename);

return "channelNumPieChart";

}catch(Exception e){
e.printStackTrace();
}

return "channelNumPieChart";
}