public class DataWriter extends XMLWriter
This filter pretty-prints field-oriented XML without mixed content. all added indentation and newlines will be passed on down the filter chain (if any).
In general, all whitespace in an XML document is potentially
significant, so a general-purpose XML writing tool like the
XMLWriter
class cannot
add newlines or indentation.
There is, however, a large class of XML documents where information is strictly fielded: each element contains either character data or other elements, but not both. For this special case, it is possible for a writing tool to provide automatic indentation and newlines without requiring extra work from the user. Note that this class will likely not yield appropriate results for document-oriented XML like XHTML pages, which mix character data and elements together.
This writer will automatically place each start tag on a new line, optionally indented if an indent step is provided (by default, there is no indentation). If an element contains other elements, the end tag will also appear on a new line with leading indentation. Consider, for example, the following code:
DataWriter w = new DataWriter(); w.setIndentStep(2); w.startDocument(); w.startElement("Person"); w.dataElement("name", "Jane Smith"); w.dataElement("date-of-birth", "1965-05-23"); w.dataElement("citizenship", "US"); w.endElement("Person"); w.endDocument();
This code will produce the following document:
<?xml version="1.0" standalone="yes"?> <Person> <name>Jane Smith</name> <date-of-birth>1965-05-23</date-of-birth> <citizenship>US</citizenship> </Person>
This class inherits from XMLWriter
, and provides all of the same support for Namespaces.
Use system platform end-of-line sequence instead of just \n.
Use typed collections.
Philip R. Burns. 2007/04/23 .
LINE_SEPARATOR
Constructor and Description |
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DataWriter()
Create a new data writer for standard output.
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DataWriter(java.io.Writer writer)
Create a new data writer for the specified output.
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DataWriter(org.xml.sax.XMLReader xmlreader)
Create a new data writer for standard output.
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DataWriter(org.xml.sax.XMLReader xmlreader,
java.io.Writer writer)
Create a new data writer for the specified output.
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Modifier and Type | Method and Description |
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void |
characters(char[] ch,
int start,
int length)
Write a sequence of characters.
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void |
emptyElement(java.lang.String uri,
java.lang.String localName,
java.lang.String qName,
org.xml.sax.Attributes atts)
Write a empty element tag.
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void |
endElement(java.lang.String uri,
java.lang.String localName,
java.lang.String qName)
Write an end tag.
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int |
getIndentStep()
Return the current indent step.
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void |
reset()
Reset the writer so that it can be reused.
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void |
setIndentStep(int indentStep)
Set the current indent step.
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void |
startElement(java.lang.String uri,
java.lang.String localName,
java.lang.String qName,
org.xml.sax.Attributes atts)
Write a start tag.
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characters, dataElement, dataElement, dataElement, emptyElement, emptyElement, endDocument, endElement, endElement, flush, forceNSDecl, forceNSDecl, getPrefix, ignorableWhitespace, processingInstruction, setDoctype, setOutput, setOutputCharsAsIs, setPrefix, startDocument, startElement, startElement, write, write, writeEsc
endPrefixMapping, error, fatalError, getContentHandler, getDTDHandler, getEntityResolver, getErrorHandler, getFeature, getParent, getProperty, notationDecl, parse, parse, resolveEntity, setContentHandler, setDocumentLocator, setDTDHandler, setEntityResolver, setErrorHandler, setFeature, setParent, setProperty, skippedEntity, startPrefixMapping, unparsedEntityDecl, warning
public DataWriter()
public DataWriter(org.xml.sax.XMLReader xmlreader)
Use the XMLReader provided as the source of events.
xmlreader
- The parent in the filter chain.public DataWriter(java.io.Writer writer)
writer
- The character stream where the XML document
will be written.public DataWriter(org.xml.sax.XMLReader xmlreader, java.io.Writer writer)
Use the XMLReader provided as the source of events.
xmlreader
- The parent in the filter chain.writer
- The character stream where the XML document
will be written.public int getIndentStep()
Return the current indent step: each start tag will be indented by this number of spaces times the number of ancestors that the element has.
setIndentStep(int)
public void setIndentStep(int indentStep)
indentStep
- The new indent step (0 or less for no
indentation).getIndentStep()
public void reset()
This method is especially useful if the writer failed with an exception the last time through.
reset
in class XMLWriter
XMLWriter.reset()
public void startElement(java.lang.String uri, java.lang.String localName, java.lang.String qName, org.xml.sax.Attributes atts) throws org.xml.sax.SAXException
Each tag will begin on a new line, and will be indented by the current indent step times the number of ancestors that the element has.
The newline and indentation will be passed on down the filter chain through regular characters events.
startElement
in interface org.xml.sax.ContentHandler
startElement
in class XMLWriter
uri
- The element's Namespace URI.localName
- The element's local name.qName
- The element's qualified (prefixed) name.atts
- The element's attribute list.org.xml.sax.SAXException
- If there is an error
writing the start tag, or if a filter further
down the chain raises an exception.XMLWriter.startElement(String, String, String, Attributes)
public void endElement(java.lang.String uri, java.lang.String localName, java.lang.String qName) throws org.xml.sax.SAXException
If the element has contained other elements, the tag will appear indented on a new line; otherwise, it will appear immediately following whatever came before.
The newline and indentation will be passed on down the filter chain through regular characters events.
endElement
in interface org.xml.sax.ContentHandler
endElement
in class XMLWriter
uri
- The element's Namespace URI.localName
- The element's local name.qName
- The element's qualified (prefixed) name.org.xml.sax.SAXException
- If there is an error
writing the end tag, or if a filter further
down the chain raises an exception.XMLWriter.endElement(String, String, String)
public void emptyElement(java.lang.String uri, java.lang.String localName, java.lang.String qName, org.xml.sax.Attributes atts) throws org.xml.sax.SAXException
Each tag will appear on a new line, and will be indented by the current indent step times the number of ancestors that the element has.
The newline and indentation will be passed on down the filter chain through regular characters events.
emptyElement
in class XMLWriter
uri
- The element's Namespace URI.localName
- The element's local name.qName
- The element's qualified (prefixed) name.atts
- The element's attribute list.org.xml.sax.SAXException
- If there is an error
writing the empty tag, or if a filter further
down the chain raises an exception.XMLWriter.emptyElement(String, String, String, Attributes)
public void characters(char[] ch, int start, int length) throws org.xml.sax.SAXException
characters
in interface org.xml.sax.ContentHandler
characters
in class XMLWriter
ch
- The characters to write.start
- The starting position in the array.length
- The number of characters to use.org.xml.sax.SAXException
- If there is an error
writing the characters, or if a filter further
down the chain raises an exception.XMLWriter.characters(char[], int, int)