【发布时间】：2014-05-25 18:05:35
【问题描述】：
我想构建一个可以在 Vaadin 中显示 PDF、Word、纯/文本文档的视图。有没有办法做到这一点 ？谢谢。
【问题讨论】：
标签： java vaadin document-view
【发布时间】：2014-05-25 18:05:35
【问题描述】：
您可以尝试以下代码在 iframe 中打开文件（在任何 url 上）。
Window window = new Window();
window.setWidth("90%");
window.setHeight("90%");
BrowserFrame e = new BrowserFrame("PDF File", new ExternalResource("http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_open_parameters.pdf"));
e.setWidth("100%");
e.setHeight("100%");
window.setContent(e);
window.center();
window.setModal(true);
UI.getCurrent().addWindow(window);
【讨论】：
您可以使用 Vaadin 文档中包含的示例
https://vaadin.com/book/-/page/advanced.printing.html（参见 11.6.3. 打印 PDF）
// A user interface for a (trivial) data model from which
// the PDF is generated.
final TextField name = new TextField("Name");
name.setValue("Slartibartfast");
// This has to be clicked first to create the stream resource
final Button ok = new Button("OK");
// This actually opens the stream resource
final Button print = new Button("Open PDF");
print.setEnabled(false);
ok.addClickListener(new ClickListener() {
@Override
public void buttonClick(ClickEvent event) {
// Create the PDF source and pass the data model to it
StreamSource source =
new MyPdfSource((String) name.getValue());
// Create the stream resource and give it a file name
String filename = "pdf_printing_example.pdf";
StreamResource resource =
new StreamResource(source, filename);
// These settings are not usually necessary. MIME type
// is detected automatically from the file name, but
// setting it explicitly may be necessary if the file
// suffix is not ".pdf".
resource.setMIMEType("application/pdf");
resource.getStream().setParameter(
"Content-Disposition",
"attachment; filename="+filename);
// Extend the print button with an opener
// for the PDF resource
BrowserWindowOpener opener =
new BrowserWindowOpener(resource);
opener.extend(print);
name.setEnabled(false);
ok.setEnabled(false);
print.setEnabled(true);
}
});
layout.addComponent(name);
layout.addComponent(ok);
layout.addComponent(print);
其他有用的例子：
package com.vaadin.book.examples.advanced;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Date;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import org.apache.fop.apps.FOUserAgent;
import org.apache.fop.apps.Fop;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.MimeConstants;
import com.vaadin.book.examples.BookExampleBundle;
import com.vaadin.terminal.ExternalResource;
import com.vaadin.terminal.StreamResource;
import com.vaadin.terminal.StreamResource.StreamSource;
import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import com.vaadin.ui.CustomComponent;
import com.vaadin.ui.Label;
import com.vaadin.ui.TextField;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.Window;
public class PrintingExample extends CustomComponent implements BookExampleBundle {
private static final long serialVersionUID = 97529549237L;
public void init(String context) {
VerticalLayout layout = new VerticalLayout();
if ("this".equals(context))
printThisPage();
else if ("open".equals(context))
printOpenedPage();
else if ("nonblocking".equals(context))
printNonblockingPage();
else if ("pdfgeneration".equals(context))
pdfgeneration(layout);
else
setCompositionRoot(new Label("Invalid Context"));
if (getCompositionRoot() == null)
setCompositionRoot(layout);
}
void printThisPage () {
// BEGIN-EXAMPLE: advanced.printing.this
final Button print = new Button("Print This Page");
print.addListener(new ClickListener() {
private static final long serialVersionUID = 15335453452L;
public void buttonClick(ClickEvent event) {
print.getWindow().executeJavaScript("print();");
}
});
// END-EXAMPLE: advanced.printing.this
setCompositionRoot(print);
}
void printOpenedPage () {
// BEGIN-EXAMPLE: advanced.printing.open
// A button to open the printer-friendly page.
Button print = new Button("Click to Print");
print.addListener(new Button.ClickListener() {
private static final long serialVersionUID = 6588417468637527327L;
public void buttonClick(ClickEvent event) {
// Create a window that contains what you want to print
Window window = new Window("Window to Print");
// Have some content to print
window.addComponent(new Label(
"<h1>Here's some dynamic content</h1>\n" +
"<p>This is to be printed to the printer.</p>",
Label.CONTENT_XHTML));
// Add the printing window as a new application-level
// window
getApplication().addWindow(window);
// Open it as a popup window with no decorations
getWindow().open(new ExternalResource(window.getURL()),
"_blank", 500, 200, // Width and height
Window.BORDER_NONE); // No decorations
// Print automatically when the window opens.
// This call will block until the print dialog exits!
window.executeJavaScript("print();");
// Close the window automatically after printing
window.executeJavaScript("self.close();");
}
});
// END-EXAMPLE: advanced.printing.open
setCompositionRoot(print);
}
// TODO: This actually blocks also.
void printNonblockingPage () {
// A button to open the printer-friendly page.
final Button print = new Button("Click to Print");
print.addListener(new Button.ClickListener() {
private static final long serialVersionUID = 349852897523897L;
public void buttonClick(ClickEvent event) {
// Content to be printed. Must double-quote newlines.
String content = "<h1>Stuff to Print</h1>\\n" +
"<p>Important stuff</p>\\n";
// The code to print and close the window
content += "<SCRIPT language=\"JavaScript\">" +
" print();" +
" close();" +
"</SCRIPT>";
// Open the print window
String js = "popup = window.open('', 'mywindow','status=1,width=350,height=150');\n" +
"popup.document.write('"+content+"');\n";
print.getWindow().executeJavaScript(js);
}
});
setCompositionRoot(print);
}
public final static String pdfgenerationDescription =
"<h1>Generating a Printable PDF</h1>" +
"<p>You can generate a PDF file dynamically using a <b>StreamResource</b>. The following example does it using the Apache FOP.</p>";
// BEGIN-EXAMPLE: advanced.printing.pdfgeneration
/** Generates the PDF dynamically when requested by HTTP. */
class MyPdfSource implements StreamSource {
private static final long serialVersionUID = 6580720404794033932L;
String name; // A trivial content data model
/** Constructor gets a content data model as parameter */
public MyPdfSource(String name) {
this.name = name;
}
@Override
public InputStream getStream() {
// Generate the FO content. You could use the Java DOM API
// here as well and pass the DOM to the transformer.
String fo = "<?xml version='1.0' encoding='ISO-8859-1'?>\n"+
"<fo:root xmlns:fo='http://www.w3.org/1999/XSL/Format'>\n"+
"<fo:layout-master-set>"+
" <fo:simple-page-master master-name='A4' margin='2cm'>"+
" <fo:region-body />"+
" </fo:simple-page-master>"+
"</fo:layout-master-set>"+
"<fo:page-sequence master-reference='A4'>"+
" <fo:flow flow-name='xsl-region-body'>"+
" <fo:block text-align='center'>"+
"Hello There, "+ name + "!</fo:block>"+
" </fo:flow>"+
"</fo:page-sequence>"+
"</fo:root>\n";
ByteArrayInputStream foStream =
new ByteArrayInputStream(fo.getBytes());
// Basic FOP configuration. You could create this object
// just once and keep it.
FopFactory fopFactory = FopFactory.newInstance();
fopFactory.setStrictValidation(false); // For an example
// Configuration for this PDF document - mainly metadata
FOUserAgent userAgent = fopFactory.newFOUserAgent();
userAgent.setProducer("My Vaadin Application");
userAgent.setCreator("Me, Myself and I");
userAgent.setAuthor("Da Author");
userAgent.setCreationDate(new Date());
userAgent.setTitle("Hello to " + name);
userAgent.setKeywords("PDF Vaadin example");
userAgent.setTargetResolution(300); // DPI
// Transform to PDF
ByteArrayOutputStream fopOut = new ByteArrayOutputStream();
try {
Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF,
userAgent, fopOut);
TransformerFactory factory =
TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
Source src = new
javax.xml.transform.stream.StreamSource(foStream);
Result res = new SAXResult(fop.getDefaultHandler());
transformer.transform(src, res);
fopOut.close();
return new ByteArrayInputStream(fopOut.toByteArray());
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
void pdfgeneration(VerticalLayout layout) {
// A user interface for a data model from which
// the PDF is generated.
final TextField name = new TextField("Name");
name.setValue("Slartibartfast");
Button print = new Button("Open PDF");
print.addListener(new ClickListener() {
private static final long serialVersionUID = 1269425538593656695L;
@Override
public void buttonClick(ClickEvent event) {
// Create the PDF source and pass the data model to it
StreamSource source =
new MyPdfSource((String) name.getValue());
// Create the stream resource and give it a file name
String filename = "pdf_printing_example.pdf";
StreamResource resource = new StreamResource(source,
filename, getApplication());
// These settings are not usually necessary. MIME type
// is detected automatically from the file name, but
// setting it explicitly may be necessary if the file
// suffix is not ".pdf".
resource.setMIMEType("application/pdf");
resource.getStream().setParameter("Content-Disposition",
"attachment; filename="+filename);
// Open it in this window - this will either launch
// PDF viewer or let the user download the file. Could
// use "_blank" target to open in another window, but
// may not be necessary.
getWindow().open(resource);
}
});
layout.addComponent(name);
layout.addComponent(print);
}
// END-EXAMPLE: advanced.printing.pdfgeneration
}
【讨论】：