java - 使用 Itext 更改 PDF 的方向

Question

我已经在这个链接的帮助下创建了 pdf 和图表 http://viralpatel.net/blogs/generate-pie-chart-bar-graph-in-pdf-using-itext-jfreechart/ .

package net.viralpatel.pdf;

import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.io.FileOutputStream;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.general.DefaultPieDataset;

import com.itextpdf.text.Document;
import com.itextpdf.text.pdf.DefaultFontMapper;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;

public class PieChartDemo {    
public static void main(String[] args) {
     //TODO: Add code to generate PDFs with charts
    writeChartToPDF(generateBarChart(), 500, 400, "C://barchart.pdf");
    writeChartToPDF(generatePieChart(), 500, 400, "C://piechart.pdf");
}

public static void writeChartToPDF(JFreeChart chart, int width, int height, String fileName) {
    PdfWriter writer = null;

    Document document = new Document();

    try {
        writer = PdfWriter.getInstance(document, new FileOutputStream(
                fileName));
        document.open();
        PdfContentByte contentByte = writer.getDirectContent();
        PdfTemplate template = contentByte.createTemplate(width, height);
        Graphics2D graphics2d = template.createGraphics(width, height,
                new DefaultFontMapper());
        Rectangle2D rectangle2d = new Rectangle2D.Double(0, 0, width,
                height);

        chart.draw(graphics2d, rectangle2d);

        graphics2d.dispose();
        contentByte.addTemplate(template, 0, 0);

    } catch (Exception e) {
        e.printStackTrace();
    }
    document.close();
}

public static JFreeChart generatePieChart() {
    DefaultPieDataset dataSet = new DefaultPieDataset();
    dataSet.setValue("China", 19.64);
    dataSet.setValue("India", 17.3);
    dataSet.setValue("United States", 4.54);
    dataSet.setValue("Indonesia", 3.4);
    dataSet.setValue("Brazil", 2.83);
    dataSet.setValue("Pakistan", 2.48);
    dataSet.setValue("Bangladesh", 2.38);

    JFreeChart chart = ChartFactory.createPieChart(
            "World Population by countries", dataSet, true, true, false);

    return chart;
}

public static JFreeChart generateBarChart() {
    DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
    dataSet.setValue(791, "Population", "1750 AD");
    dataSet.setValue(978, "Population", "1800 AD");
    dataSet.setValue(1262, "Population", "1850 AD");
    dataSet.setValue(1650, "Population", "1900 AD");
    dataSet.setValue(2519, "Population", "1950 AD");
    dataSet.setValue(6070, "Population", "2000 AD");

    JFreeChart chart = ChartFactory.createBarChart(
            "World Population growth", "Year", "Population in millions",
            dataSet, PlotOrientation.VERTICAL, false, true, false);

    return chart;
}

现在如何将 pdf 的方向从 prtrait 更改为横向？

Answer 1

当您像这样创建一个 Document 对象时:

Document document = new Document();

您告诉 iText 使用纵向创建包含 A4 格式页面的文档。您可以添加一个 Rectangle 对象作为 Document 构造函数的参数，以创建包含您想要的任何大小的页面的文档。

您还可以使用 PageSize 类来使用预定义的格式。例如:如果您想横向使用 A4 页面，您可以使用:

Document document = new Document(PageSize.A4.rotate());

请download the free eBook "The ABC of PDF"了解更多信息。