GraphicImage

package org.primefaces.showcase.view.multimedia;

import org.primefaces.model.DefaultStreamedContent;
import org.primefaces.model.StreamedContent;

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;

import jakarta.enterprise.context.RequestScoped;
import jakarta.inject.Named;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtils;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;

@Named
@RequestScoped
public class GraphicImageView {

    public StreamedContent getGraphicText() {
        return DefaultStreamedContent.builder()
                .contentType("image/png")
                .stream(() -> {
                    try {
                        BufferedImage bufferedImg = new BufferedImage(100, 25, BufferedImage.TYPE_INT_RGB);
                        Graphics2D g2 = bufferedImg.createGraphics();
                        g2.drawString("This is a text", 0, 10);
                        ByteArrayOutputStream os = new ByteArrayOutputStream();
                        ImageIO.write(bufferedImg, "png", os);
                        return new ByteArrayInputStream(os.toByteArray());
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                        return null;
                    }
                })
                .build();
    }

    public StreamedContent getChart() {
        return DefaultStreamedContent.builder()
                .contentType("image/png")
                .stream(() -> {
                    try {
                        JFreeChart jfreechart = ChartFactory.createPieChart("Cities", createDataset(), true, true, false);
                        File chartFile = new File("dynamichart");
                        ChartUtils.saveChartAsPNG(chartFile, jfreechart, 375, 300);
                        return new FileInputStream(chartFile);
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                        return null;
                    }
                })
                .build();
    }

    public StreamedContent getChartWithoutBuffering() {
        return DefaultStreamedContent.builder()
                .contentType("image/png")
                .writer((os) -> {
                    try {
                        JFreeChart jfreechart = ChartFactory.createPieChart("Cities", createDataset(), true, true, false);
                        ChartUtils.writeChartAsPNG(os, jfreechart, 375, 300);
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                    }
                })
                .build();
    }

    public InputStream getChartAsStream() {
        return getChart().getStream().get();
    }

    public byte[] getChartAsByteArray() throws IOException {
        InputStream is = getChartAsStream();
        byte[] array = new byte[is.available()];
        is.read(array);
        return array;
    }

    private PieDataset<String> createDataset() {
        DefaultPieDataset<String> dataset = new DefaultPieDataset<String>();
        dataset.setValue("New York", Double.valueOf(45.0));
        dataset.setValue("London", Double.valueOf(15.0));
        dataset.setValue("Paris", Double.valueOf(25.2));
        dataset.setValue("Berlin", Double.valueOf(14.8));

        return dataset;
    }
}