com.sun.pdfview.PDFFile

com.sun.pdfview.PDFFile 是一个Java程序包中的类，用于读取和操作PDF文件。它提供了一种方便的方式来获取PDF文件的内容，并对其进行操作和呈现。该类可以解析PDF文件中的所有内容，并允许您访问PDF文档的结构树、页面、注释、书签、元数据等。它还提供了一些有用的方法来处理PDF文件，例如搜索、旋转、缩放、裁剪、合并、拆分等。

相关问题

java 实现file 转pdf预览代码

您好！以下是Java实现file转PDF预览的代码：

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Rectangle2D;
import java.awt.print.PageFormat;
import java.awt.print.Paper;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

import javax.swing.JFrame;
import javax.swing.JPanel;

import com.sun.pdfview.PDFFile;
import com.sun.pdfview.PDFPage;
import com.sun.pdfview.PagePanel;

public class PDFConverter {
    public static void main(String[] args) {
        JFrame frame = new JFrame("File to PDF Preview");

        try {
            File file = new File("test.pdf");

            FileInputStream fis = new FileInputStream(file.getAbsolutePath());
            PDFFile pdfFile = new PDFFile(fis);

            PDFPrintPage pages = new PDFPrintPage(pdfFile);

            frame.add(pages);
            frame.pack();
            frame.setVisible(true);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    static class PDFPrintPage extends JPanel implements Printable {
        private static final long serialVersionUID = 1L;
        private PDFFile file;
        private int pageIndex = 0;

        public PDFPrintPage(PDFFile file) {
            this.file = file;
            setPreferredSize(new Dimension(800, 1000));
        }

        @Override
        public int print(Graphics g, PageFormat format, int pageIndex) {
            if (pageIndex >= file.getNumPages()) {
                return NO_SUCH_PAGE;
            }

            Graphics2D g2 = (Graphics2D) g;

            PDFPage page = file.getPage(pageIndex + 1);

            double pwidth = format.getImageableWidth();
            double pheight = format.getImageableHeight();

            double aspect = page.getAspectRatio();
            double paperAspect = pwidth / pheight;

            double scaleFactor = 1.0;
            if (aspect > paperAspect) {
                // The PDF aspect ratio is wider than the paper aspect
                scaleFactor = pwidth / page.getWidth();
            } else {
                // The PDF aspect ratio is taller than the paper aspect
                scaleFactor = pheight / page.getHeight();
            }

            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
            g2.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);

            double cx = (format.getImageableX() + format.getWidth()) / 2.0;
            double cy = (format.getImageableY() + format.getHeight()) / 2.0;

            Rectangle2D rect = page.getBBox();

            rect.setRect(rect.getX() * scaleFactor + cx - (page.getWidth() * scaleFactor) / 2.0,
                    rect.getY() * scaleFactor + cy - (page.getHeight() * scaleFactor) / 2.0,
                    rect.getWidth() * scaleFactor, rect.getHeight() * scaleFactor);

            PagePanel panel = new PagePanel();
            panel.showPage(page);

            try {
                panel.print(g);
            } catch (PrinterException e) {
                e.printStackTrace();
            }

            pageIndex++;

            return PAGE_EXISTS;
        }
    }
}

希望对您有所帮助！