I'm trying to create a PDF document with Apache Library FOP. It works well but I have to create a temp file to store an intermediate file (test.fop).
Here is my function:
#RequestMapping(value = "/pdf")
public void showPdfReport(OutputStream pdfOutStream) throws Exception
{
// Setup
FopFactory fopFactory = FopFactory.newInstance();
TransformerFactory factory = TransformerFactory.newInstance();
// Transformation XML to XML-FO
StreamSource xsltSource = new StreamSource(servletContext.getResourceAsStream("resources/xsl/pdfTemplate.fo"));
Transformer transformer = factory.newTransformer(xsltSource);
OutputStream fopOutStream = new BufferedOutputStream(new FileOutputStream(new File(
"C:/Temp/tests/test.fop")));
StreamSource xmlSource = new StreamSource(servletContext.getResourceAsStream("resources/xsl/test.xml"));
StreamResult fopResult = new StreamResult(fopOutStream);
transformer.transform(xmlSource, fopResult);
// Transformation XSL-FO to PDF
Source fopSrc = new StreamSource(new File("C:/Temp/tests/test.fop"));
Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, pdfOutStream);
Result res = new SAXResult(fop.getDefaultHandler());
transformer = factory.newTransformer();
transformer.transform(fopSrc, res);
}
Is it possible to store test.fop in a stream or any buffer instead of a file?
There's an example on the FOP website that explains exactly this. The SAX events emitted from the XSLT transformation are directly fed into FOP. No buffering in a file or in memory.
Sure, you can pass any Reader or InputStream to the StreamSource constructor
You could use StringReader or ByteArrayInputStream for example.
Related
How do I write this document to the local filesystem?
public void docToFile(org.w3c.dom.Document document, URI path) throws Exception {
File file = new File(path);
}
I need to iterate the document, or might there be a "to xml/html/string" method? I was looking at:
document.getXmlEncoding();
Not quite what I'm after -- but something like that. Looking for the String representation and then to write that to file like:
Path file = ...;
byte[] buf = ...;
Files.write(file, buf);
https://docs.oracle.com/javase/tutorial/essential/io/file.html
I would use a transformer class to convert the DOM content to an xml file, something like below:
Document doc =...
// write the content into xml file
DOMSource source = new DOMSource(doc);
FileWriter writer = new FileWriter(new File("/tmp/output.xml"));
StreamResult result = new StreamResult(writer);
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
transformer.transform(source, result);
I hope this ends up working for you!
In this article (https://www.ahoi-it.de/ahoi/news/java-xslt-memory-leak/4830) it is explained that Javax xml transformer caches XML contents to its internal HashMap for later use.
This is my issue: I am reading XML messages from activemq and if something fails, I retry to convert them again using Javax XML transformer and send them to certain endpoint. The problem is that eventually my Docker container restarts because it runs out of memory.
What I would like to do is disable caching, unfortunately, after 3 hours of research I still have no idea how to do so.
I have a utils class with static methods and this is how my Javax XML Transformer looks like:
public static String getTransformedXml(Object input, String transformerFileName)
throws IOException, TransformerException {
ClassPathResource classPathResource = new ClassPathResource(transformerFileName);
InputStream xsltStream = classPathResource.getInputStream();
TransformerFactory factory = TransformerFactory.newInstance();
Source xslt = new StreamSource(xsltStream);
Transformer transformer = factory.newTransformer(xslt);
transformer.setErrorListener(new XsltTransformerErrorListener(transformerFileName));
Source text = new StreamSource(new StringReader(XmlUtils.encode(input, input.getClass())));
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);
transformer.transform(text, result);
return result.getWriter().toString();
}
Try to change the TransformerFactoryImpl :
TransformerFactory tFactory = TransformerFactory.newInstance("org.apache.xalan.processor.TransformerFactoryImpl",null);
I have a process of XML transform in which I am writing the output transformed XML to a file. But instead of storing it in a file I want to store it in a string variable. I have created a string variable, please advise how can I store the generated XML in a string variable (msgxml instead of writing a file).
String msgxml;
System.setProperty("javax.xml.transform.TransformerFactory",
"org.apache.xalan.processor.TransformerFactoryImpl");
FileInputStream xml = new FileInputStream(xmlInput);
FileInputStream xsl = new FileInputStream(xslInput);
FileOutputStream os = new FileOutputStream(outputXmlFile);
TransformerFactory tFactory = TransformerFactory.newInstance();
// Use the TransformerFactory to process the stylesheet source and produce a Transformer
StreamSource styleSource = new StreamSource(xsl);
Transformer transformer = tFactory.newTransformer(styleSource);
StreamSource xmlSource = new StreamSource(xml);
StreamResult result = new StreamResult(os);
//here we are storing it in a file ,
try {
transformer.transform(xmlSource, result);
} catch (TransformerException e) {
e.printStackTrace();
}
One way is to use an ByteArrayOutputStream instead of a FileOutputStream:
ByteArrayOutputStream baos = new ByteArrayOutputStream();
TransformerFactory tFactory = TransformerFactory.newInstance();
...
StreamSource xmlSource = new StreamSource(xml);
StreamResult result = new StreamResult(baos); // write to the byte array stream
//here we are storing it in a file ,
try {
transformer.transform(xmlSource, result);
}
...
msgxml = baos.toString("UTF-8"); // get contents of stream using UTF-8 encoding
Another solution is to use a java.io.StringWriter:
StringWriter stringWriter = new StringWriter();
StreamResult result = new StreamResult(stringWriter);
...
msgxml = stringWriter.toString();
I am trying to write an XML file. I was able to create the Document using the following code. I want to write this Document to a file with indent support. Currently my code looks like this.
Which is a better technology to parse XMl and write to a file.
public void writeXmlToFile(Document dom) throws IOException {
OutputFormat format = new OutputFormat(dom);
format.setIndenting(true);
XMLSerializer serializer = new XMLSerializer ( new FileOutputStream(
new File("sample.xml")), format);
serializer.serialize(dom);
}
or is using transformer a better approach.
public void writeXMLToFile(DOcument dom) throws TransformerException, IOException {
TransformerFactory transFact = TransformerFactory.newInstance();
Transformer trans = transFact.newTransformer();
trans.setOutputProperty(OutputKeys.ENCODING, "utf-8");
trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
trans.setOutputProperty(OutputKeys.INDENT, "yes");
trans.setOutputProeprty("{http://xml.apache.org/xslt}indent-amount", "2");
StreamResult resut = new StreamResult(new FileWriter(output));
DOMSource source = new DOMSource(xmlDOC);
trans.transform(source, result);
writer.close();
}
What is the difference between the two approaches? And which of these techniques provide better performance?
To answer your question, I would suggest a third way which is the W3C proposed DOM Load and Save API. The code is self-explaining.
DOMImplementationLS ls = (DOMImplementationLS)
DOMImplementationRegistry.newInstance().getDOMImplementation("LS");
// Gets a basic document from string.
LSInput input = ls.createLSInput();
String xml = "<bookstore city='shanghai'><a></a><b/></bookstore>";
InputStream istream = new ByteArrayInputStream(xml.getBytes("UTF-8"));
input.setByteStream(istream);
LSParser parser = ls.createLSParser(DOMImplementationLS.MODE_SYNCHRONOUS, null);
Document document = parser.parse(input);
// Creates a LSSerializer object and saves to file.
LSSerializer serializer = ls.createLSSerializer();
serializer.getDomConfig().setParameter("format-pretty-print", true);
LSOutput output = ls.createLSOutput();
OutputStream ostream = new FileOutputStream("c:\\temp\\foo.xml");
output.setByteStream(ostream);
serializer.write(document, output);
Unlike XmlSerializer which is more or less a pre-standard, this approach is preferred as it is supported by all compliant implementations. The performance largely depends on vendor implementation though.
I am using NekoHTML to parse contents of some HTML file..
Everything goes okay except for extracting the contents of the Document Object to some string.
I've tried uses
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(writer);
transformer.transform(source, result);
But nothing appears returned.
The problem where in Oracle App server 10.3.1.4 http://m-hewedy.blogspot.com/2011/04/oracle-application-server-overrides.html
Posible solution:
//this nekohtml
DOMParser parser = new DOMParser();
parser.parse(archivo);
//this xerces
OutputFormat format = new OutputFormat(parser.getDocument());
format.setIndenting(true);
//print xml for console
//XMLSerializer serializer = new XMLSerializer(System.out, format);
//save xml in string var
OutputStream outputStream = new ByteArrayOutputStream();
XMLSerializer serializer = new XMLSerializer(outputStream, format);
//process
serializer.serialize(parser.getDocument());
String xmlText = outputStream.toString();
System.out.println(xmlText);
//to generate a file output use fileoutputstream instead of system.out
//XMLSerializer serializer = new XMLSerializer(new FileOutputStream(new File("book.xml")), format);
Url: http://totheriver.com/learn/xml/xmltutorial.html#6.2
See e) Serialize DOM to FileOutputStream to generate the xml file "book.xml" .