jfreechat 折线图

 

package com.test.jfree;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DatasetUtilities;
//JFreeChart Line Chart（折线图）  
public class CreateJFreeChartLine {

public static void main(String[] args) {
   // 步骤1：创建CategoryDataset对象（准备数据）
   CategoryDataset dataset = createDataset();
   // 步骤2：根据Dataset 生成JFreeChart对象，以及做相应的设置
   JFreeChart freeChart = createChart(dataset);
   // 步骤3：将JFreeChart对象输出到文件，Servlet输出流等
   saveAsFile(freeChart, "c:\\line.jpg", 600, 400);
}
// 保存为文件
public static void saveAsFile(JFreeChart chart, String outputPath,
    int weight, int height) {
   FileOutputStream out = null;
   try {
    File outFile = new File(outputPath);
    if (!outFile.getParentFile().exists()) {
     outFile.getParentFile().mkdirs();
    }
    out = new FileOutputStream(outputPath);
    // 保存为PNG
    //ChartUtilities.writeChartAsPNG(out, chart, 600, 400);
    // 保存为JPEG
    ChartUtilities.writeChartAsJPEG(out, chart, 600, 400);
    out.flush();
   } catch (FileNotFoundException e) {
    e.printStackTrace();
   } catch (IOException e) {
    e.printStackTrace();
   } finally {
    if (out != null) {
     try {
      out.close();
     } catch (IOException e) {
      // do nothing
     }
    }
   }
}

// 根据CategoryDataset创建JFreeChart对象
public static JFreeChart createChart(CategoryDataset categoryDataset) {
   // 创建JFreeChart对象：ChartFactory.createLineChart
   JFreeChart jfreechart = ChartFactory.createLineChart("不同类别按小时计算拆线图", // 标题
     "年分", // categoryAxisLabel （category轴，横轴，X轴标签）
     "数量", // valueAxisLabel（value轴，纵轴，Y轴的标签）
     categoryDataset, // dataset
     PlotOrientation.VERTICAL, true, // legend
     false, // tooltips
     false); // URLs
  
   // 使用CategoryPlot设置各种参数。以下设置可以省略。
   CategoryPlot plot = (CategoryPlot) jfreechart.getPlot();
   // 背景色 透明度
   plot.setBackgroundAlpha(0.5f);
   // 前景色 透明度
   plot.setForegroundAlpha(0.5f);
   // 其他设置 参考 CategoryPlot类
  
   return jfreechart;
}


public static CategoryDataset createDataset() {
  
   String[] rowKeys = { "A平台" };
   String[] colKeys = { "0:00", "1:00", "2:00", "7:00", "8:00", "9:00",
     "10:00", "11:00", "12:00", "13:00", "16:00", "20:00", "21:00",
     "23:00" };
  
   double[][] data = { { 4, 3, 1, 1, 1, 1, 2, 2, 2, 1, 8, 2, 1, 1 }, };
  
   // 或者使用类似以下代码
   // DefaultCategoryDataset categoryDataset = new
   // DefaultCategoryDataset();
   // categoryDataset.addValue(10, "rowKey", "colKey");
   return DatasetUtilities.createCategoryDataset(rowKeys, colKeys, data);
}
}