使用jfreechart统计数据，生成折线图（坐标x,y值大小可以自己设置）

public static JFreeChart createXYLineChart(java.lang.String title,
java.lang.String xAxisLabel,
java.lang.String yAxisLabel,
XYDataset dataset,
PlotOrientation orientation,
boolean legend,
boolean tooltips,
boolean urls)

XYDataset

title

null

xAxisLabel

null

yAxisLabel

null

dataset

null

orientation

null

legend

tooltips

urls

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class GetData {

//从一个txt文件中读取数据
public static List writeToData(String path) {
File file = new File(path);
List list = new ArrayList();

try {
BufferedReader bw = new BufferedReader(new FileReader(file));
String line = null;
//先存入list集合中
while((line = bw.readLine()) != null){
list.add(line);
}
bw.close();
} catch (IOException e) {
e.printStackTrace();
}

return list;
}

//求数组元素的平均值
public static double average(double table[]) {

double sum=0.0;

for (int i=0;i<table.length;i++) {
sum += table[i];
}
return sum / table.length;

}

}

import java.awt.Font;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartFrame;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

public class LineChart {

// 保存为图像文件
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, weight, height);
//保存为JPEG
//ChartUtilities.writeChartAsJPEG(out, chart, weight, height);
out.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
// do nothing
}
}
}
}

//接口名
static String interfaceName;

public static XYSeriesCollection createDataSet(String fileName) {

//要处理的txt文件的路径
String path = "e:\\interfaceTest\\gz\\" + fileName;
//获取接口名
String result = path.substring(0,path.length()-4);
interfaceName = result.substring(20, result.length());

//获取数据，放到数组中
List list = GetData.writeToData(path);

double[] nums = new double[list.size()];

for(int k=0; k < list.size(); k++){
String s = (String) list.get(k);
nums[k] = Double.parseDouble(s);
}

double ave = GetData.average(nums);

System.out.println("ave: " + ave);

XYSeriesCollection seriesCollection = new XYSeriesCollection();
XYSeries series1 = new XYSeries(interfaceName + "接口，平均响应时间：" + ave + "ms");

for(int i=0; i < list.size(); i++){
series1.add(i, nums[i]);
}

seriesCollection.addSeries(series1);

return seriesCollection;
}

public static void createLineChart(String fileName) {

JFreeChart chart = ChartFactory.createXYLineChart("响应时间统计",           //图表标题
"接口调用次数",                   //X轴标题
"响应时间（毫秒）",                //Y轴标题
createDataSet(fileName),     //绘图数据集
PlotOrientation.VERTICAL,    //绘制方向
true,                        //显示图例
true,                        //采用标准生成器
false);                      //是否生成超链接

//ChartFrame frame=new ChartFrame("接口响应时间统计",chart);

//设置标题字体
chart.getTitle().setFont(new Font("宋体", Font.BOLD, 15));
chart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 15)); // 设置图例类别字体
//获取图表区域对象
XYPlot plot = (XYPlot) chart.getPlot();

ValueAxis domainAxis=plot.getDomainAxis();
domainAxis.setTickLabelFont(new Font("黑体", Font.BOLD, 15));
/*------设置X轴坐标上的文字-----------*/
domainAxis.setTickLabelFont(new Font("黑体", Font.PLAIN, 11));
/*------设置X轴的标题文字------------*/
domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));

NumberAxis numberaxis = (NumberAxis) plot.getRangeAxis();
/*------设置Y轴坐标上的文字-----------*/
numberaxis.setTickLabelFont(new Font("黑体", Font.PLAIN, 12));
/*------设置Y轴的标题文字------------*/
numberaxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));

//终端显示
//frame.pack();
//frame.setVisible(true);

System.out.println(interfaceName);

//保存图像的大小
int weight = 800;
int height = 600;
//存放图像的目录
String outputPath = "e:\\interfaceTest\\imgs\\" + interfaceName + ".png";
//String outputPath = "d:\\interface\\imgs\\" + interfaceName + ".png";
LineChart.saveAsFile(chart, outputPath, weight, height);
}

public static void main(String[] args) {
//存放.txt的目录
File file = new File("e:\\interfaceTest\\gz\\");
if(file.isDirectory())
{
File[] files = file.listFiles();
for(File myFile:files)
{
if(myFile.isFile())
{
createLineChart(myFile.getName());
}
}
}

}
}