在JavaFX中开发桌面应用程序，需要显示PDF。我了解到当前版本的JavaFX不支持PDF查看/显示，我也了解了JPedal。
现在，有几个问题：
- 是否有外部组件或库可以在JavaFX中查看PDF？它应该是免费的。
- （如果我必须使用
JPedal）如何将其嵌入我的应用程序。
4个回答
13
JPedalFX示例代码及使用
使用JPedalFX的示例代码可在JPedalFX下载页面中找到。
我这边可能有些不太好，但我会在此处粘贴一些从JPedalFX库提供的示例查看器中复制的代码片段。该代码依赖于在类路径上（或应用程序jar清单中引用的库路径）包含在JPedalFX分发中包含的jpedal_lgpl.jar文件。
如果您对JPedalFX的使用有任何疑问，请建议直接联系IDR Solutions（他们曾经对我进行过响应）。
// get file path.
FileChooser fc = new FileChooser();
fc.setTitle("Open PDF file...");
fc.getExtensionFilters().add(new FileChooser.ExtensionFilter("PDF Files", "*.pdf"));
File f = fc.showOpenDialog(stage.getOwner());
String filename = file.getAbsolutePath();
// open file.
PdfDecoder pdf = new PdfDecoder();
pdf.openPdfFile(filename);
showPage(1);
pdf.closePdfFile();
. . .
/**
* Update the GUI to show a specified page.
* @param page
*/
private void showPage(int page) {
//Check in range
if (page > pdf.getPageCount())
return;
if (page < 1)
return;
//Store
pageNumber = page;
//Show/hide buttons as neccessary
if (page == pdf.getPageCount())
next.setVisible(false);
else
next.setVisible(true);
if (page == 1)
back.setVisible(false);
else
back.setVisible(true);
//Calculate scale
int pW = pdf.getPdfPageData().getCropBoxWidth(page);
int pH = pdf.getPdfPageData().getCropBoxHeight(page);
Dimension s = Toolkit.getDefaultToolkit().getScreenSize();
s.width -= 100;
s.height -= 100;
double xScale = (double)s.width / pW;
double yScale = (double)s.height / pH;
double scale = xScale < yScale ? xScale : yScale;
//Work out target size
pW *= scale;
pH *= scale;
//Get image and set
Image i = getPageAsImage(page,pW,pH);
imageView.setImage(i);
//Set size of components
imageView.setFitWidth(pW);
imageView.setFitHeight(pH);
stage.setWidth(imageView.getFitWidth()+2);
stage.setHeight(imageView.getFitHeight()+2);
stage.centerOnScreen();
}
/**
* Wrapper for usual method since JFX has no BufferedImage support.
* @param page
* @param width
* @param height
* @return
*/
private Image getPageAsImage(int page, int width, int height) {
BufferedImage img;
try {
img = pdf.getPageAsImage(page);
//Use deprecated method since there's no real alternative
//(for JavaFX 2.2+ can use SwingFXUtils instead).
if (Image.impl_isExternalFormatSupported(BufferedImage.class))
return javafx.scene.image.Image.impl_fromExternalImage(img);
} catch(Exception e) {
e.printStackTrace();
}
return null;
}
/**
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.jpedal.org
* (C) Copyright 1997-2008, IDRsolutions and Contributors.
*
* This file is part of JPedal
*
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---------------
* JPedalFX.java
* ---------------
*/
SwingLabs PDF Renderer
此外，我过去曾使用过一个基于SwingLabs Swing的老式pdf渲染器和JavaFX一起为我的JavaFX Web浏览器渲染pdf。尽管当时我开发浏览器时，Swing/JavaFX集成不是JavaFX的支持功能，但对我来说仍然很有效。 集成代码在PDFViewer.java和BrowserWindow.java中。
请注意，将JavaFX嵌入Swing应用程序在Java 2.2中受到支持，并且在Java 8中支持在JavaFX中嵌入Swing应用程序。
- jewelsea
1
10JPedalFX现在不是免费的:/ - GlacialMan
12
好的，这是我的50美分。除了@ALabrosik和@ReneEnriquez的答案外。
下载pdf.js dist并将其放置在src/main/resources下。
├── pom.xml
├── src
│ └── main
│ ├── java
│ │ └── me
│ │ └── example
│ │ ├── JSLogListener.java
│ │ ├── Launcher.java
│ │ └── WebController.java
│ └── resources
│ ├── build
│ │ ├── pdf.js
│ │ └── pdf.worker.js
│ ├── main.fxml
│ ├── web
│ │ ├── cmaps
│ │ ├── compatibility.js
│ │ ├── debugger.js
│ │ ├── images
│ │ ├── l10n.js
│ │ ├── locale
│ │ ├── viewer.css
│ │ ├── viewer.html
│ │ └── viewer.js
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Tab?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.web.WebView?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="576.0" prefWidth="1024.0" xmlns="http://javafx.com/javafx/8.0.112" xmlns:fx="http://javafx.com/fxml/1" fx:controller="me.example.WebController">
<center>
<TabPane>
<tabs>
<Tab text="PDF test">
<content>
<WebView fx:id="web" minHeight="-1.0" minWidth="-1.0" />
</content>
</Tab>
</tabs>
</TabPane>
</center>
<bottom>
<Button fx:id="btn" mnemonicParsing="false" text="Open another file" BorderPane.alignment="CENTER" />
</bottom>
</BorderPane>
为了防止pdf.js在启动时打开演示pdf文件，请打开web/viewer.js并清除DEFAULT_URL的值。
var DEFAULT_URL = '';
打开 web/viewer.html 文件，并添加脚本块：
<head>
<!-- ... -->
<script src="viewer.js"></script>
<!-- CUSTOM BLOCK -->
<script>
var openFileFromBase64 = function(data) {
var arr = base64ToArrayBuffer(data);
console.log(arr);
PDFViewerApplication.open(arr);
}
function base64ToArrayBuffer(base64) {
var binary_string = window.atob(base64);
var len = binary_string.length;
var bytes = new Uint8Array( len );
for (var i = 0; i < len; i++) {
bytes[i] = binary_string.charCodeAt(i);
}
return bytes.buffer;
}
</script>
<!-- end of CUSTOM BLOCK -->
</head>
现在是控制器（请参阅代码注释以了解说明）。
public class WebController implements Initializable {
@FXML
private WebView web;
@FXML
private Button btn;
public void initialize(URL location, ResourceBundle resources) {
WebEngine engine = web.getEngine();
String url = getClass().getResource("/web/viewer.html").toExternalForm();
// connect CSS styles to customize pdf.js appearance
engine.setUserStyleSheetLocation(getClass().getResource("/web.css").toExternalForm());
engine.setJavaScriptEnabled(true);
engine.load(url);
engine.getLoadWorker()
.stateProperty()
.addListener((observable, oldValue, newValue) -> {
// to debug JS code by showing console.log() calls in IDE console
JSObject window = (JSObject) engine.executeScript("window");
window.setMember("java", new JSLogListener());
engine.executeScript("console.log = function(message){ java.log(message); };");
// this pdf file will be opened on application startup
if (newValue == Worker.State.SUCCEEDED) {
try {
// readFileToByteArray() comes from commons-io library
byte[] data = FileUtils.readFileToByteArray(new File("/path/to/file"));
String base64 = Base64.getEncoder().encodeToString(data);
// call JS function from Java code
engine.executeScript("openFileFromBase64('" + base64 + "')");
} catch (Exception e) {
e.printStackTrace();
}
}
});
// this file will be opened on button click
btn.setOnAction(actionEvent -> {
try {
byte[] data = FileUtils.readFileToByteArray(new File("/path/to/another/file"));
String base64 = Base64.getEncoder().encodeToString(data);
engine.executeScript("openFileFromBase64('" + base64 + "')");
} catch (Exception e) {
e.printStackTrace();
}
});
}
}
pdf.js的某些功能将无法使用：打开文件（因为pdf.js无法访问JAR外部的URL）、打印等。要隐藏相应的工具栏按钮，您可以将以下行添加到web.css中：
#toolbarViewerRight {
display:none;
}
就这些。剩下的代码都很简单。
public class JSLogListener {
public void log(String text) {
System.out.println(text);
}
}
public class Launcher extends Application {
public static void main(String[] args) {
Application.launch();
}
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("/main.fxml"));
primaryStage.setTitle("PDF test app");
primaryStage.setScene(new Scene(root, 1280, 576));
primaryStage.show();
}
}
希望这对某人有所帮助。
- enzo
3
1非常感谢您的解释和示例！我已经在我的应用程序上使其工作。我只是进行了一些修改，因为相对的“..”链接在JAR中无法工作。因此，当所有内容都被捆绑在一起时，查看器无法正常工作。我根据您的评论进行了快速文章撰写，并进行了修改，这里是链接：https://blog.samirhadzic.com/2017/02/09/show-pdf-in-your-application/
谢谢！ - Maxoudela
展示你的
WebController 类的 imports。 - SedJ601非常感谢，我按照评论和博客文章的方法解决了问题，这是一个好的解决方案。但是，如果有人需要帮助，请允许我补充一些内容。如果您要使用PDF.js，请不要使用当前版本（v2.0.943），因为它无法呈现PDF文档的文本。请使用当前的beta 2.1.266或之前的版本1.10.100，否则文本将无法呈现。
https://dev59.com/SLDla4cB1Zd3GeqP946Q#54767956 - oizulain
11
我建议使用PDF JS JavaScript库。
创建一个WebView并静态加载这个JavaScript pdf viewer example project的HTML/JavaScript内容。创建一个JavaScript函数，可以将PDF字节数组发送到该函数来显示。
这样PDF浏览器的所有逻辑都已经存在。你甚至可以修改视图器的HTML以删除一些功能。
同时要注意JPedalFX，因为我发现它在渲染添加到PDF文件中的图片时不太可靠。在我的情况下，JPedalFX无法渲染使用jfreechart生成的图表图像。
- ALabrosk
2
1你能否详细说明一下这个问题？ - Tommo
2你可以在下面的答案中看到解决方案（https://dev59.com/XWMl5IYBdhLWcg3wr4rn#42040344）。无论如何，老实说，我们最终使用了[PDFBox]（https://pdfbox.apache.org/）。客户想要左<->右滑动来更改页面，所以结果发现操作pdf.js有点困难。制作我们自己的自定义pdf阅读器对我们和我们的客户都有效 :) - ALabrosk
-3
package de.vogella.itext.write;
import java.io.FileOutputStream;
import java.util.Date;
import com.itextpdf.text.Anchor;
import com.itextpdf.text.BadElementException;
import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Chapter;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.List;
import com.itextpdf.text.ListItem;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Section;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;
public class FirstPdf {
private static String FILE = "c:/temp/FirstPdf.pdf";
private static Font catFont = new Font(Font.FontFamily.TIMES_ROMAN, 18,
Font.BOLD);
private static Font redFont = new Font(Font.FontFamily.TIMES_ROMAN, 12,
Font.NORMAL, BaseColor.RED);
private static Font subFont = new Font(Font.FontFamily.TIMES_ROMAN, 16,
Font.BOLD);
private static Font smallBold = new Font(Font.FontFamily.TIMES_ROMAN, 12,
Font.BOLD);
public static void main(String[] args) {
try {
Document document = new Document();
PdfWriter.getInstance(document, new FileOutputStream(FILE));
document.open();
addMetaData(document);
addTitlePage(document);
addContent(document);
document.close();
} catch (Exception e) {
e.printStackTrace();
}
}
// iText allows to add metadata to the PDF which can be viewed in your Adobe
// Reader
// under File -> Properties
private static void addMetaData(Document document) {
document.addTitle("My first PDF");
document.addSubject("Using iText");
document.addKeywords("Java, PDF, iText");
document.addAuthor("Lars Vogel");
document.addCreator("Lars Vogel");
}
private static void addTitlePage(Document document)
throws DocumentException {
Paragraph preface = new Paragraph();
// We add one empty line
addEmptyLine(preface, 1);
// Lets write a big header
preface.add(new Paragraph("Title of the document", catFont));
addEmptyLine(preface, 1);
// Will create: Report generated by: _name, _date
preface.add(new Paragraph("Report generated by: " + System.getProperty("user.name") + ", " + new Date(), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
smallBold));
addEmptyLine(preface, 3);
preface.add(new Paragraph("This document describes something which is very important ",
smallBold));
addEmptyLine(preface, 8);
preface.add(new Paragraph("This document is a preliminary version and not subject to your license agreement or any other agreement with vogella.com ;-).",
redFont));
document.add(preface);
// Start a new page
document.newPage();
}
private static void addContent(Document document) throws DocumentException {
Anchor anchor = new Anchor("First Chapter", catFont);
anchor.setName("First Chapter");
// Second parameter is the number of the chapter
Chapter catPart = new Chapter(new Paragraph(anchor), 1);
Paragraph subPara = new Paragraph("Subcategory 1", subFont);
Section subCatPart = catPart.addSection(subPara);
subCatPart.add(new Paragraph("Hello"));
subPara = new Paragraph("Subcategory 2", subFont);
subCatPart = catPart.addSection(subPara);
subCatPart.add(new Paragraph("Paragraph 1"));
subCatPart.add(new Paragraph("Paragraph 2"));
subCatPart.add(new Paragraph("Paragraph 3"));
// add a list
createList(subCatPart);
Paragraph paragraph = new Paragraph();
addEmptyLine(paragraph, 5);
subCatPart.add(paragraph);
// add a table
createTable(subCatPart);
// now add all this to the document
document.add(catPart);
// Next section
anchor = new Anchor("Second Chapter", catFont);
anchor.setName("Second Chapter");
// Second parameter is the number of the chapter
catPart = new Chapter(new Paragraph(anchor), 1);
subPara = new Paragraph("Subcategory", subFont);
subCatPart = catPart.addSection(subPara);
subCatPart.add(new Paragraph("This is a very important message"));
// now add all this to the document
document.add(catPart);
}
private static void createTable(Section subCatPart)
throws BadElementException {
PdfPTable table = new PdfPTable(3);
// t.setBorderColor(BaseColor.GRAY);
// t.setPadding(4);
// t.setSpacing(4);
// t.setBorderWidth(1);
PdfPCell c1 = new PdfPCell(new Phrase("Table Header 1"));
c1.setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(c1);
c1 = new PdfPCell(new Phrase("Table Header 2"));
c1.setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(c1);
c1 = new PdfPCell(new Phrase("Table Header 3"));
c1.setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(c1);
table.setHeaderRows(1);
table.addCell("1.0");
table.addCell("1.1");
table.addCell("1.2");
table.addCell("2.1");
table.addCell("2.2");
table.addCell("2.3");
subCatPart.add(table);
}
private static void createList(Section subCatPart) {
List list = new List(true, false, 10);
list.add(new ListItem("First point"));
list.add(new ListItem("Second point"));
list.add(new ListItem("Third point"));
subCatPart.add(list);
}
private static void addEmptyLine(Paragraph paragraph, int number) {
for (int i = 0; i < number; i++) {
paragraph.add(new Paragraph(" "));
}
}
}
- Moslem Cherif
1
2问题是查看现有的还是嵌入它。 - diego matos - keke
网页内容由stack overflow 提供, 点击上面的可以查看英文原文，
原文链接
原文链接