Java.lang.nullpointerexception bei com.jogamp.opengl.util.texture.spi.awt.iiotextureWriter.Write (iiotextureWriter.java: ⇐ Java

[Anonymous]

Ich visualisiere die Datei des 3D -Flusses in der XY -Ebene -Projektion aus der Datei wie dieser < /p>

Code: Select all

VARIABLES="X","Y","Z","U","V","W"
ZONE F=FEPOINT ET=BRICK N=1331 E=1000
0.000000    0.000000    0.000000    0.000000    0.000000    0.000000
1.000000    0.000000    0.000000    0.000000    0.000000    0.000000
1.000000    1.000000    0.000000    1.000000    0.000000    0.000000
< /code>
mit dem folgenden Code: < /p>
package com.example.laminarflow;

import org.jzy3d.chart.AWTChart;
import org.jzy3d.chart.Chart;
import org.jzy3d.chart.factories.AWTChartComponentFactory;
import org.jzy3d.chart.factories.AWTChartFactory;
import org.jzy3d.colors.Color;
import org.jzy3d.maths.Coord3d;
import org.jzy3d.plot3d.rendering.canvas.Quality;
import org.jzy3d.plot3d.primitives.Scatter;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.awt.Graphics2D;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class NavierStokes2DVisualization {
public static void main(String[] args) {
try {

List velocityData = readVelocityData("NavierStokesBox3D/grids/stokes_cavity3d2_uvw01_00.dat");

Chart chart = new AWTChartFactory().newChart(Quality.Fastest());
Scatter scatter = new Scatter(velocityData.toArray(new Coord3d[0]));
scatter.setWidth(3.0f);
scatter.setColor(Color.BLUE);
chart.getScene().add(scatter);

saveChartAsImage(chart, "D:\\Java\\windmodel\\wind_projection.jpg");

System.out.println("Visualization saved to wind_projection.jpg");
} catch (Exception e) {
e.printStackTrace();
}
}

private static List readVelocityData(String filePath) throws IOException {
List points = new ArrayList();
BufferedReader reader = new BufferedReader(new FileReader(filePath));
String line;
while ((line = reader.readLine()) != null) {
String[] values = line.trim().split("\\s+");
if (values.length >= 6) {
double x = Double.parseDouble(values[0]);
double y = Double.parseDouble(values[1]);
double z = Double.parseDouble(values[2]);
double u = Double.parseDouble(values[3]);
double v = Double.parseDouble(values[4]);

if (Math.abs(z - 0.1) < 0.0001) {
points.add(new Coord3d(x + u * 0.01, y + v * 0.01, 0));
}
}
}
reader.close();
return points;
}

private static void saveChartAsImage(Chart chart, String fileName) throws IOException {
if (chart instanceof AWTChart) {
chart.render();
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}

AWTChart awtChart = (AWTChart) chart;
File file = new File(fileName);

File parentDir = file.getParentFile();

if (parentDir != null && !parentDir.exists()) {
parentDir.mkdirs();
}

awtChart.screenshot(file);
System.out.println("Chart saved successfully to " + fileName);
} else {
System.err.println("Error: Chart is not an instance of AWTChart.");
}
}
}
< /code>
und Erhalten Sie den Fehler < /p>
java.lang.NullPointerException
at com.jogamp.opengl.util.texture.spi.awt.IIOTextureWriter.write(IIOTextureWriter.java:59)
at com.jogamp.opengl.util.texture.TextureIO.write(TextureIO.java:686)
at org.jzy3d.plot3d.rendering.canvas.CanvasAWT.screenshot(CanvasAWT.java:246)
at org.jzy3d.chart.Chart.screenshot(Chart.java:282)
at com.example.laminarflow.NavierStokes2DVisualization.saveChartAsImage(NavierStokes2DVisualization.java:82)
at com.example.laminarflow.NavierStokes2DVisualization.main(NavierStokes2DVisualization.java:32)

Ich habe es müde, zwischen dem Render und der Datei zu schlafen, aber das hilft nicht viel