ConcretePage.comPretty Print XML with Java Transformer and XSLT
May 06, 2023
Transformer and XSLT.
1. Java
Transformer is an abstract class whose instance can transform a source tree into a result tree.
2. The
Transformer is instantiated using TransformerFactory.newTransformer method.
TransformerFactory transformerFactory = TransformerFactory.newInstance(); Transformer transformer = transformerFactory.newTransformer();
Transformer using transform method, can process XML from a variety of sources and write the transformation output to a variety of sinks.
void transform(Source xmlSource, Result outputTarget) throws TransformerException
Source interface, contains the source XML input.
The Source has following implementations.
DOMSource: XML source as DOM.
SAXSource: XML source as SAX-style.
StAXSource: XML source as StAX reader.
StreamSource: XML source as stream of XML markup.
In our example, we will use
StreamSource class.
Source source = new StreamSource(new File("src/main/resources/inputFile.xml"));
Result interface, contains the result tree. The Result interface has following implementations.
DOMResult: Result tree in the form of DOM tree.
SAXResult: Result in SAX-style.
StAXResult: Result in the form of a StAX writer.
StreamResult: Result in the form of markup.
In our example, we will use
StreamResult class.
Result result = new StreamResult(new File("src/main/resources/outputFile.xml"));
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
Pretty Print with Default Configurations
Find the source xml that needs to pretty print.inputFile.xml
<person created="20023-03-12T15:20" modified="20023-04-14T16:25"><firstName>Mahesh</firstName><lastName>Sharma</lastName><age>25</age> <address type="home"><village>XYZ Pur</village><city>Varanasi</city><state>UP</state><postalCode>123456</postalCode></address></person>
INDENT output property as true.
Source source = new StreamSource(new File("src/main/resources/inputFile.xml"));
Result result = new StreamResult(new File("src/main/resources/outputFile.xml"));
TransformerFactory transformerFactory = TransformerFactory.newInstance();
try {
Transformer transformer = transformerFactory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
Pretty Print By Setting Output Properties
To set output properties,Transformer has following methods.
void setOutputProperties(Properties format) void setOutputProperty(String name, String value)
transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
TransformerFactory using following method.
void setAttribute(String name, Object value)
transformerFactory.setAttribute("indent-number", 3);
Source source = new StreamSource(new File("src/main/resources/inputFile.xml"));
Result result = new StreamResult(new File("src/main/resources/outputFile.xml"));
TransformerFactory transformerFactory = TransformerFactory.newInstance();
transformerFactory.setAttribute("indent-number", 3);
try {
Transformer transformer = transformerFactory.newTransformer();
transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, "yes");
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
outputFile.xml
<?xml version="1.0" encoding="UTF-8"?>
<person created="20023-03-12T15:20" modified="20023-04-14T16:25">
<firstName>Mahesh</firstName>
<lastName>Sharma</lastName>
<age>25</age>
<address type="home">
<village>XYZ Pur</village>
<city>Varanasi</city>
<state>UP</state>
<postalCode>123456</postalCode>
</address>
</person>
Pretty Print with XSLT
Find the XSLT file.person-format.xslt
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <!-- Pretty Print Output --> <xsl:output method="xml" indent="yes" encoding="UTF-8"/> <!-- Match any element or attribute --> <xsl:template match="node()|@*"> <xsl:copy> <xsl:apply-templates select="node()|@*"/> </xsl:copy> </xsl:template> </xsl:stylesheet>
Source source = new StreamSource(new File("src/main/resources/inputFile.xml"));
Result result = new StreamResult(new File("src/main/resources/outputFile.xml"));
Source xsltSource = new StreamSource(new File("src/main/resources/person-format.xslt"));
TransformerFactory transformerFactory = TransformerFactory.newInstance();
try {
Transformer transformer = transformerFactory.newTransformer(xsltSource);
transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
<xsl:output> can have following attributes.
method="xml" | "html" | "text" version=STRING encoding=STRING omit-xml-declaration="yes" | "no" standalone="yes" | "no" doctype-public=STRING doctype-system=STRING cdata-section-elements=LIST-OF-NAMES indent="yes" | "no" media-type=STRING
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <!-- Pretty Print Output --> <xsl:output method="xml" indent="yes" omit-xml-declaration="yes" encoding="UTF-8"/> ------ </xsl:stylesheet>
