利用pdfbox完成文档制作

今天突然想制作一个linux kernel的文档出来，但是由于kernel文档里提供的是目录结构的txt文件，因此我需要生成一个pdf文件，保持对应的目录结构

找了好久，最终发现还是自己写代码实现比较靠谱，找来找去发现apache有一个叫pdfbox的库，很轻易就能实现这个需求，代码哪下

 

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.edit.PDPageContentStream;
import org.apache.pdfbox.pdmodel.font.PDSimpleFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.interactive.documentnavigation.outline.PDDocumentOutline;
import org.apache.pdfbox.pdmodel.interactive.documentnavigation.outline.PDOutlineItem;

public class PDFMaker {

	private static int fontSize = 10;
	private static PDSimpleFont font = PDType1Font.COURIER_BOLD;

	public static void addFile(PDDocument document, PDPage page, File file)
			throws Exception {

		final int margin = 40;
		float height = font.getFontDescriptor().getFontBoundingBox()
				.getHeight() / 1000;

		// calculate font height and increase by 5 percent.
		height = height * fontSize * 1.05f;
		BufferedReader data = new BufferedReader(new FileReader(file));
		String nextLine = null;
		PDPageContentStream contentStream = null;
		float y = -1;
		float maxStringLength = page.getMediaBox().getWidth() - 2 * margin;

		// There is a special case of creating a PDF document from an empty
		// string.
		boolean textIsEmpty = true;

		document.addPage(page);
		contentStream = new PDPageContentStream(document, page);
		contentStream.setFont(font, fontSize);
		contentStream.beginText();
		y = page.getMediaBox().getHeight() - margin + height;
		contentStream.moveTextPositionByAmount(margin, y);

		while ((nextLine = data.readLine()) != null) {

			// The input text is nonEmpty. New pages will be created and
			// added
			// to the PDF document as they are needed, depending on the
			// length of
			// the text.
			textIsEmpty = false;

			String[] lineWords = nextLine.trim().split(" ");
			int lineIndex = 0;
			while (lineIndex < lineWords.length) {
				StringBuffer nextLineToDraw = new StringBuffer();
				float lengthIfUsingNextWord = 0;
				do {
					nextLineToDraw.append(lineWords[lineIndex]);
					nextLineToDraw.append(" ");
					lineIndex++;
					if (lineIndex < lineWords.length) {
						String lineWithNextWord = nextLineToDraw.toString()
								+ lineWords[lineIndex];
						lengthIfUsingNextWord = (font
								.getStringWidth(lineWithNextWord) / 1000)
								* fontSize;
					}
				} while (lineIndex < lineWords.length
						&& lengthIfUsingNextWord < maxStringLength);
				if (y < margin) {
					// We have crossed the end-of-page boundary and need to
					// extend the
					// document by another page.
					page = new PDPage();
					document.addPage(page);
					if (contentStream != null) {
						contentStream.endText();
						contentStream.close();
					}
					contentStream = new PDPageContentStream(document, page);
					contentStream.setFont(font, fontSize);
					contentStream.beginText();
					y = page.getMediaBox().getHeight() - margin + height;
					contentStream.moveTextPositionByAmount(margin, y);
				}
				// System.out.println( "Drawing string at " + x + "," + y );

				if (contentStream == null) {
					throw new IOException(
							"Error:Expected non-null content stream.");
				}
				contentStream.moveTextPositionByAmount(0, -height);
				y -= height;
				contentStream.drawString(nextLineToDraw.toString());
			}

		}

		// If the input text was the empty string, then the above while loop
		// will have short-circuited
		// and we will not have added any PDPages to the document.
		// So in order to make the resultant PDF document readable by Adobe
		// Reader etc, we'll add an empty page.
		if (textIsEmpty) {
			document.addPage(page);
		}

		if (contentStream != null) {
			contentStream.endText();
			contentStream.close();
		}
	}

	public static PDPage addDir(PDDocument document, PDOutlineItem root,
			PDPage page, File dir) throws Exception {
		if (!dir.isDirectory()) {
			throw new Exception("not directory");
		}

		for (File file : dir.listFiles()) {
			if (page == null) {
				page = new PDPage();
			}
			String name = file.getName();
			PDOutlineItem item = new PDOutlineItem();
			item.setTitle(name);
			root.appendChild(item);
			if (file.isDirectory()) {
				addDir(document, item, page, file);
			} else {
				addFile(document, page, file);
			}
			item.setDestination(page);
			page = null;
		}

		return page;
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			PDDocument document = new PDDocument();
			PDDocumentOutline outline = new PDDocumentOutline();
			document.getDocumentCatalog().setDocumentOutline(outline);

			// Create a root element to show in the tree
			PDOutlineItem root = new PDOutlineItem();
			root.setTitle("Outline");
			outline.appendChild(root);

			addDir(document, root, null, new File("f:/Documentation"));

			document.save("f:/test.pdf");
			document.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}