概述
軟體要求
實現過程
[一]、概述

前面已經介紹瞭如何實現對HTML中文字元的轉換以及HTML檔案生成PDF檔案的基本方法，本文主要演示下如何把URL地址對應的內容直接轉換生成PDF檔案，這個需求也有很多的應用場景，最簡單的應用場景比如：自己blog中的文章如何轉PDF，如果能生成PDF檔案，一方面可以方便自己的閱讀，亦可作為一種備份。

[二]、軟體要求

org.jsoup
jsoup
1.7.1
jar
compile

1
2
3
4
5
6
7

org.jsoup
jsoup
1.7.1
jar
compile

[三]、實現過程

Java實現程式碼：Demo4URL2PDF.java

package com.bigdata.ai.util.pdf;

import java.io.ByteArrayInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.jsoup.Jsoup;

import com.itextpdf.text.BaseColor;
import
 
 com.itextpdf.text.Chapter;
import com.itextpdf.text.Chunk;
import com.itextpdf.text.Document;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Section;
import com.itextpdf.text.pdf.BaseFont;
import
 
 com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.pdf.draw.LineSeparator;
import com.itextpdf.tool.xml.ElementHandler;
import com.itextpdf.tool.xml.Writable;
import com.itextpdf.tool.xml.XMLWorkerHelper;
import com.itextpdf.tool.xml.pipeline.WritableElement;

/**  
 * 依據jsoup.jar包和itextReader匯出pdf文件
 * @file Demo4URL2Pdf.java
 * @package com.bigdata.ai.util.pdf
 * @author dxh
 * @createTime 2017年8月23日08:05:31  
*/
public class Demo4URL2Pdf {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        String blogURL = "http://www.micmiu.com/os/linux/shell-dev-null/";

        // 直接把網頁內容轉為PDF檔案
        String pdfFile = "d:/test/itext/demo-URL.pdf";
        Demo4URL2Pdf.parseURL2PDFFile(pdfFile, blogURL);

        // 把網頁內容轉為PDF中的Elements
        String pdfFile2 = "d:/test/itext/demo-URL2.pdf";
        Demo4URL2Pdf.parseURL2PDFElement(pdfFile2, blogURL);
    }
    /**
     * 根據URL提前blog的基本資訊，返回結果>>:[主題 ,分類,日期,內容]等.
     *
     * @param blogURL
     * @return
     * @throws Exception
     */
    public static String[] extractBlogInfo(String blogURL) throws Exception {
        String[] info = new String[4];
        org.jsoup.nodes.Document doc = Jsoup.connect(blogURL).get();
        org.jsoup.nodes.Element e_title = doc.select("h2.title").first();
        info[0] = e_title.text();

        org.jsoup.nodes.Element e_category = doc.select("a[rel=category tag]")
                .first();
        info[1] = e_category.attr("href").replace("http://www.micmiu.com/", "");

        org.jsoup.nodes.Element e_date = doc.select("span.post-info-date")
                .first();

        String dateStr = e_date.text().split("日期")[1].trim();
        info[2] = dateStr;
        org.jsoup.nodes.Element entry = doc.select("div.entry").first();
        info[3] = formatContentTag(entry);

        return info;
    }

    /**
     * 格式化 img標籤
     *
     * @param entry
     * @return
     */
    private static String formatContentTag(org.jsoup.nodes.Element entry) {
        try {
            entry.select("div").remove();
            // 把 <a href="*.jpg" ><img src="*.jpg"/></a> 替換為 <img
            // src="*.jpg"/>
            for (org.jsoup.nodes.Element imgEle : entry
                    .select("a[href~=(?i)\\.(png|jpe?g)]")) {
                imgEle.replaceWith(imgEle.select("img").first());
            }
            return entry.html();
        } catch (Exception e) {
            return "";
        }
    }

    /**
     * 把String 轉為 InputStream
     *
     * @param content
     * @return
     */
    public static InputStream parse2Stream(String content) {
        try {
            ByteArrayInputStream stream = new ByteArrayInputStream(
                    content.getBytes("utf-8"));
            return stream;
        } catch (Exception e) {

            return null;
        }
    }

    /**
     * 直接把網頁內容轉為PDF檔案
     *
     * @param fileName
     * @throws Exception
     */
    public static void parseURL2PDFFile(String pdfFile, String blogURL)
            throws Exception {

        BaseFont bfCN = BaseFont.createFont("C:/WINDOWS/Fonts/SIMYOU.TTF", BaseFont.IDENTITY_H,BaseFont.NOT_EMBEDDED);
        // 中文字型定義
        Font chFont = new Font(bfCN, 14, Font.NORMAL, BaseColor.BLUE);
        Font secFont = new Font(bfCN, 12, Font.NORMAL, new BaseColor(0, 204,
                255));
        Font textFont = new Font(bfCN, 12, Font.NORMAL, BaseColor.BLACK);

        Document document = new Document();
        PdfWriter pdfwriter = PdfWriter.getInstance(document,
                new FileOutputStream(pdfFile));
        pdfwriter.setViewerPreferences(PdfWriter.HideToolbar);
        document.open();

        String[] blogInfo = extractBlogInfo(blogURL);

        int chNum = 1;
        Chapter chapter = new Chapter(new Paragraph("URL轉PDF測試", chFont),
                chNum++);

        Section section = chapter
                .addSection(new Paragraph(blogInfo[0], secFont));
        section.setIndentation(10);
        section.setIndentationLeft(10);
        section.setBookmarkOpen(false);
        section.setNumberStyle(Section.NUMBERSTYLE_DOTTED_WITHOUT_FINAL_DOT);
        section.add(new Chunk("分類：" + blogInfo[1] + " 日期：" + blogInfo[2],
                textFont));

        LineSeparator line = new LineSeparator(1, 100, new BaseColor(204, 204,
                204), Element.ALIGN_CENTER, -2);
        Paragraph p_line = new Paragraph(" ");
        p_line.add(line);
        section.add(p_line);
        section.add(Chunk.NEWLINE);

        document.add(chapter);

        // html檔案
        XMLWorkerHelper.getInstance().parseXHtml(pdfwriter, document,
                parse2Stream(blogInfo[3]));

        document.close();
    }

    /**
     * 把網頁內容轉為PDF中的Elements
     *
     * @param pdfFile
     * @param htmlFileStream
     */
    public static void parseURL2PDFElement(String pdfFile, String blogURL) {
        try {
            Document document = new Document(PageSize.A4);

            FileOutputStream outputStream = new FileOutputStream(pdfFile);
            PdfWriter pdfwriter = PdfWriter.getInstance(document, outputStream);
            // pdfwriter.setViewerPreferences(PdfWriter.HideToolbar);
            document.open();

            BaseFont bfCN = BaseFont.createFont("C:/WINDOWS/Fonts/SIMYOU.TTF", BaseFont.IDENTITY_H,BaseFont.NOT_EMBEDDED);
            // 中文字型定義
            Font chFont = new Font(bfCN, 14, Font.NORMAL, BaseColor.BLUE);
            Font secFont = new Font(bfCN, 12, Font.NORMAL, new BaseColor(0,
                    204, 255));
            Font textFont = new Font(bfCN, 12, Font.NORMAL, BaseColor.BLACK);

            int chNum = 1;
            Chapter chapter = new Chapter(new Paragraph("URL轉PDF元素，便於追加其他內容",
                    chFont), chNum++);

            String[] blogInfo = extractBlogInfo(blogURL);

            Section section = chapter.addSection(new Paragraph(blogInfo[0],
                    secFont));

            section.setIndentation(10);
            section.setIndentationLeft(10);
            section.setBookmarkOpen(false);
            section.setNumberStyle(Section.NUMBERSTYLE_DOTTED_WITHOUT_FINAL_DOT);
            section.add(new Chunk("分類：" + blogInfo[1] + " 發表日期：" + blogInfo[2],
                    textFont));
            LineSeparator line = new LineSeparator(1, 100, new BaseColor(204,
                    204, 204), Element.ALIGN_CENTER, -2);
            Paragraph p_line = new Paragraph();
            p_line.add(line);
            section.add(p_line);
            section.add(Chunk.NEWLINE);

            final List<Element> pdfeleList = new ArrayList<Element>();
            ElementHandler elemH = new ElementHandler() {

                public void add(final Writable w) {
                    if (w instanceof WritableElement) {
                        pdfeleList.addAll(((WritableElement) w).elements());
                    }

                }
            };
            XMLWorkerHelper.getInstance().parseXHtml(elemH,
                    new InputStreamReader(parse2Stream(blogInfo[3]), "utf-8"));

            List<Element> list = new ArrayList<Element>();
            for (Element ele : pdfeleList) {
                if (ele instanceof LineSeparator
                        || ele instanceof WritableElement) {
                    continue;
                }
                list.add(ele);
            }
            section.addAll(list);

            section = chapter.addSection(new Paragraph("繼續新增章節", secFont));

            section.setIndentation(10);
            section.setIndentationLeft(10);
            section.setBookmarkOpen(false);
            section.setNumberStyle(Section.NUMBERSTYLE_DOTTED_WITHOUT_FINAL_DOT);
            section.add(new Chunk("測試URL轉為PDF元素，方便追加其他內容", textFont));

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

    }
}