将 CSV 文件中的数据读入 ArrayList 并在 XY 图表中显示

本文介绍了将 CSV 文件中的数据读入 ArrayList 并在 XY 图表中显示的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我想显示一段时间内的温度曲线.我现在已经阅读了一个类似于 CSV 的文件，它让我知道指示的时间和温度.现在我想使用 JFreeChart 从值中显示 XY 图.文件的原始数据如下所示:

utc,local,celsius2017-07-12T07:02:53+00:00,2017-07-12T09:02:53+02:00,26.252017-07-12T08:02:54+00:00,2017-07-12T10:02:54+02:00,26.082017-07-12T09:02:55+00:00,2017-07-12T11:02:55+02:00,25.782017-07-12T10:02:56+00:00,2017-07-12T12:02:56+02:00,25.962017-07-12T10:51:02+00:00,2017-07-12T12:51:02+02:00,26.142017-07-12T10:51:02+00:00,2017-07-12T12:51:02+02:00,26.14

输出时间&温度值(我已经从原始文件中分离出来)看起来像:

09:02:53,26.2510:02:54,26.0811:02:55,25.7812:02:56,25.9612:51:02,26.1412:51:02,26.14

现在我在 Trashgod 的例子中插入了一个 DateTimeFormatter:看起来像:

公共类测试{公共静态无效主(字符串 [] args){EventQueue.invokeLater(() -> {ApplicationFrame frame = new ApplicationFrame("CSVTest");测试测试=新测试()；frame.add(test.createChart("温度曲线"));框架.pack();frame.setLocationRelativeTo(null);;frame.setVisible(true);});}私人 ChartPanel createChart(String chartTitle) {JFreeChart 图表 = ChartFactory.createTimeSeriesChart(chartTitle,"时间", "温度", createDataset(), true, true, false);ChartPanel chartPanel = new ChartPanel(chart);XYPlot 图 = chart.getXYPlot();DateAxis domain = (DateAxis) plot.getDomainAxis();domain.setDateFormatOverride(DateFormat.getDateInstance());plot.setBackgroundPaint(Color.WHITE);返回图表面板；}私人 XYDataset createDataset() {TimeSeries 系列 = new TimeSeries("Temperature");TimeSeriesCollection 数据集 = new TimeSeriesCollection(series);试试 (FileReader fr = new FileReader("TestCSV.csv");BufferedReader br = 新的 BufferedReader(fr)) {字符串线；br.readLine();while ((line = br.readLine()) != null) {String[] split = line.split(",");System.out.println(ZonedDateTime.parse(split[1]).format(DateTimeFormatter.ISO_LOCAL_TIME) + "," +split[2]);ZonedDateTime zdt = ZonedDateTime.of(LocalDate.now(),LocalTime.parse(split[0]), ZoneId.systemDefault());String s = ZonedDateTime.parse(split[0]).format(DateTimeFormatter.ISO_LOCAL_TIME);第二秒 = new Second(Date.from(zdt.toInstant()));series.add(second, Double.valueOf(split[1]));}} catch (IOException | SeriesException e) {System.err.println("错误:" + e);}返回数据集；}

CSV"类文件的第一行仍然显示 09:02:53,26.25然后我得到一个 DateTimeParseException: Text '2017-07-12T09:02:53+02:00' could not be parsed at index 2

线程AWT-EventQueue-0"中的异常java.time.format.DateTimeParseException:无法在索引2处解析文本2017-07-12T07:02:53+00:00"在 java.time.format.DateTimeFormatter.parseResolved0(来源不明)在 java.time.format.DateTimeFormatter.parse(Unknown Source)在 java.time.LocalTime.parse(来源不明)在 java.time.LocalTime.parse(来源不明)在 org.jfree.chart.demo.Test.createDataset(Test.java:63)在 org.jfree.chart.demo.Test.createChart(Test.java:43)在 org.jfree.chart.demo.Test.lambda$0(Test.java:34)

为什么不能读取或显示文件的其余部分?(System.out.println()"应该只作为最后的控制).DateTimeFomatter 是正确的，不是吗?

根据你的方法，我在本地制作的时间不多了&该程序无法翻译.我做错了什么?直接输出怎么用

09:02:53,26.2510:02:54,26.0811:02:55,25.7812:02:56,25.9612:51:02,26.1412:51:02,26.14

显示在图表中?我认为像我一样分裂和转变是可以的，不是吗?现在我在代码中设置了 setDateFormatOverride()，但错误信息以及输出保持不变.

解决方案

几个问题很明显:

你从不向行添加任何东西；至少，你需要这样的东西:
```
lines.add(line);
```
考虑创建时间序列，而不是 ChartFactory.createXYLineChart():
```
ChartFactory.createTimeSeriesChart(…)
```

createDataset() 返回的 XYDataset 应该是您添加

import java.awt.Color;导入 java.awt.EventQueue;导入 java.io.BufferedReader;导入 java.io.FileReader;导入 java.io.IOException;导入 java.text.SimpleDateFormat;导入 java.time.ZonedDateTime;导入 java.util.Date;导入 java.util.TimeZone;导入 org.jfree.chart.ChartFactory;导入 org.jfree.chart.ChartPanel;导入 org.jfree.chart.JFreeChart;导入 org.jfree.chart.axis.DateAxis;导入 org.jfree.chart.plot.XYPlot;导入 org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;导入 org.jfree.data.general.SeriesException;导入 org.jfree.data.time.Second;导入 org.jfree.data.time.TimeSeries;导入 org.jfree.data.time.TimeSeriesCollection;导入 org.jfree.data.xy.XY 数据集；导入 org.jfree.ui.ApplicationFrame;/** @see https://stackoverflow.com/a/45173688/230513 */公共类 CSVTest {公共静态无效主(字符串 [] args){EventQueue.invokeLater(() -> {ApplicationFrame frame = new ApplicationFrame("CSVTest");CSVTest 测试 = 新的 CSVTest();frame.add(test.createChart("温度曲线"));框架.pack();frame.setLocationRelativeTo(null);;frame.setVisible(true);});}私人 ChartPanel createChart(String chartTitle) {JFreeChart 图表 = ChartFactory.createTimeSeriesChart(chartTitle,"时间", "温度", createDataset(), true, true, false);ChartPanel chartPanel = new ChartPanel(chart);XYPlot 图 = chart.getXYPlot();plot.setBackgroundPaint(Color.WHITE);XYLineAndShapeRenderer r = (XYLineAndShapeRenderer) plot.getRenderer();r.setBaseShapesVisible(true);DateAxis 轴 = (DateAxis) plot.getDomainAxis();SimpleDateFormat df = new SimpleDateFormat("HH:mm:ssX");df.setTimeZone(TimeZone.getTimeZone("UTC"));轴.setDateFormatOverride(df);返回图表面板；}私人 XYDataset createDataset() {TimeSeries 系列 = new TimeSeries("Temperature");TimeSeriesCollection 数据集 = new TimeSeriesCollection(series);试试 (FileReader fr = new FileReader("temp.csv");BufferedReader br = 新的 BufferedReader(fr)) {字符串线；while ((line = br.readLine()) != null) {String[] s = line.split(",");ZonedDateTime zdt = ZonedDateTime.parse(s[0]);第二秒 = new Second(Date.from(zdt.toInstant()));series.add(second, Double.valueOf(s[2]));}} catch (IOException | SeriesException e) {System.err.println("错误:" + e);}返回数据集；}}

I would like to display a temperature curve over time. I have now read a file, which is CSV-similar, that let me know the time and the temperature indicated. Now I want to use JFreeChart to display an XY graph from the values.The original data of the file looks as follows:

utc,local,celsius
2017-07-12T07:02:53+00:00,2017-07-12T09:02:53+02:00,26.25
2017-07-12T08:02:54+00:00,2017-07-12T10:02:54+02:00,26.08
2017-07-12T09:02:55+00:00,2017-07-12T11:02:55+02:00,25.78
2017-07-12T10:02:56+00:00,2017-07-12T12:02:56+02:00,25.96
2017-07-12T10:51:02+00:00,2017-07-12T12:51:02+02:00,26.14
2017-07-12T10:51:02+00:00,2017-07-12T12:51:02+02:00,26.14

The output of time & temperature values (I have separated from the original file) looks like:

09:02:53,26.25
10:02:54,26.08
11:02:55,25.78
12:02:56,25.96
12:51:02,26.14
12:51:02,26.14

EDIT:Now I have inserted a DateTimeFormatter in the example from Trashgod:It looks like:

public class Test {
public static void main(String[] args) {
    EventQueue.invokeLater(() -> {
        ApplicationFrame frame = new ApplicationFrame("CSVTest");
        Test test = new Test();
        frame.add(test.createChart("Temperature profile"));
        frame.pack();
        frame.setLocationRelativeTo(null);;
        frame.setVisible(true);
    });
}

private ChartPanel createChart(String chartTitle) {
    JFreeChart chart = ChartFactory.createTimeSeriesChart(chartTitle,
        "Time", "Temperature", createDataset(), true, true, false);
    ChartPanel chartPanel = new ChartPanel(chart);
    XYPlot plot = chart.getXYPlot();
    DateAxis domain = (DateAxis) plot.getDomainAxis();
    domain.setDateFormatOverride(DateFormat.getDateInstance());
    plot.setBackgroundPaint(Color.WHITE);
    return chartPanel;
}


    private XYDataset createDataset() {
    TimeSeries series = new TimeSeries("Temperature");
    TimeSeriesCollection dataset = new TimeSeriesCollection(series);
    try (FileReader fr = new FileReader("TestCSV.csv");
        BufferedReader br = new BufferedReader(fr)) {
        String line;
        br.readLine();
        while ((line = br.readLine()) != null) {
            String[] split = line.split(",");

           System.out.println(ZonedDateTime.parse(split[1]).format(DateTimeFormatter.ISO_LOCAL_TIME)  + "," +split[2]);
           ZonedDateTime zdt = ZonedDateTime.of(LocalDate.now(),LocalTime.parse(split[0]), ZoneId.systemDefault());
           String s = ZonedDateTime.parse(split[0]).format(DateTimeFormatter.ISO_LOCAL_TIME);

           Second second =  new Second(Date.from(zdt.toInstant()));
           series.add(second, Double.valueOf(split[1]));
        }
    } catch (IOException | SeriesException e) {
        System.err.println("Error: " + e);
    }
    return dataset;
}

The first line of the "CSV" -like file is still displayed 09:02:53,26.25Then I get a DateTimeParseException: Text '2017-07-12T09:02:53+02:00' could not be parsed at index 2

Exception in thread "AWT-EventQueue-0" java.time.format.DateTimeParseException: Text '2017-07-12T07:02:53+00:00' could not be parsed at index 2
at java.time.format.DateTimeFormatter.parseResolved0(Unknown Source)
at java.time.format.DateTimeFormatter.parse(Unknown Source)
at java.time.LocalTime.parse(Unknown Source)
at java.time.LocalTime.parse(Unknown Source)
at org.jfree.chart.demo.Test.createDataset(Test.java:63)
at org.jfree.chart.demo.Test.createChart(Test.java:43)
at org.jfree.chart.demo.Test.lambda$0(Test.java:34)

Why can not the rest of the file be read nor displayed?("System.out.println()" should only serve as a control at the end). The DateTimeFomatter is correct, isn´t it?

With your approach, the time to make locally I come no further & the program can not translate. What did I do wrong? How could it work if the direct output

09:02:53,26.25
10:02:54,26.08
11:02:55,25.78
12:02:56,25.96
12:51:02,26.14
12:51:02,26.14

is displayed in a chart? I think to split and to transform like I did is okay, isn´t it? Now I have setDateFormatOverride () in the code, but the error message, as well as the output remain the same.

解决方案

Several problems are evident:

You never add anything to lines; at a minimum, you'll need something like this:
```
lines.add(line);
```
Instead of ChartFactory.createXYLineChart(), consider creating a time series:
```
ChartFactory.createTimeSeriesChart(…)
```
The XYDataset returned by createDataset() should be a TimeSeriesCollection to which you add a TimeSeries.
In createDataset(), iterate though lines, parse the data fields, and add the values to the TimeSeries.
The time values given are most closely modeled by LocalTime, but TimeSeries expects to add() coordinates defined by a RegularTimePeriod and a double; see Legacy Date-Time Code concerning the conversion shown below.
Note that TimeSeries throws SeriesException for duplicate domain values; as a result, only three of the four lines int eh sample input air charted.
Instead of replacing the factory supplied XYLineAndShapeRenderer, get a reference to it for later modification.
Alter the chart's size using one of the approaches shown here.
Avoid extending top-level containers line ApplicationFrame.
Construct and manipulate Swing GUI objects only on the event dispatch thread.
Use a try-with-resources statement to ensure that each resource is closed at the end of the statement.
As your actual data contains ISO 8601 dates, ZonedDateTime.parse() can be used directly; use setDateFormatOverride() to format the date axis labels; the example below specifies a UTC time zone in ISO 8601 format for easy comparison; comment out the call to setDateFormatOverride() to see the times in your local time zone.

import java.awt.Color;
import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.time.ZonedDateTime;
import java.util.Date;
import java.util.TimeZone;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.general.SeriesException;
import org.jfree.data.time.Second;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.ApplicationFrame;

/** @see https://stackoverflow.com/a/45173688/230513 */
public class CSVTest {

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            ApplicationFrame frame = new ApplicationFrame("CSVTest");
            CSVTest test = new CSVTest();
            frame.add(test.createChart("Temperature profile"));
            frame.pack();
            frame.setLocationRelativeTo(null);;
            frame.setVisible(true);
        });
    }

    private ChartPanel createChart(String chartTitle) {
        JFreeChart chart = ChartFactory.createTimeSeriesChart(chartTitle,
            "Time", "Temperature", createDataset(), true, true, false);
        ChartPanel chartPanel = new ChartPanel(chart);
        XYPlot plot = chart.getXYPlot();
        plot.setBackgroundPaint(Color.WHITE);
        XYLineAndShapeRenderer r = (XYLineAndShapeRenderer) plot.getRenderer();
        r.setBaseShapesVisible(true);
        DateAxis axis = (DateAxis) plot.getDomainAxis();
        SimpleDateFormat df = new SimpleDateFormat("HH:mm:ssX");
        df.setTimeZone(TimeZone.getTimeZone("UTC"));
        axis.setDateFormatOverride(df);
        return chartPanel;
    }

    private XYDataset createDataset() {
        TimeSeries series = new TimeSeries("Temperature");
        TimeSeriesCollection dataset = new TimeSeriesCollection(series);
        try (FileReader fr = new FileReader("temp.csv");
            BufferedReader br = new BufferedReader(fr)) {
            String line;
            while ((line = br.readLine()) != null) {
                String[] s = line.split(",");
                ZonedDateTime zdt = ZonedDateTime.parse(s[0]);
                Second second = new Second(Date.from(zdt.toInstant()));
                series.add(second, Double.valueOf(s[2]));
            }
        } catch (IOException | SeriesException e) {
            System.err.println("Error: " + e);
        }
        return dataset;
    }
}

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