com.sun.xml.internal.txw2.output: public class: DataWriter

com.sun.xml.internal.txw2.output
public class: DataWriter [javadoc | source]

java.lang.Object
   org.xml.sax.helpers.XMLFilterImpl
      com.sun.xml.internal.txw2.output.XMLWriter
         com.sun.xml.internal.txw2.output.DataWriter

All Implemented Interfaces:
LexicalHandler, ContentHandler, DTDHandler, ErrorHandler, XMLFilter, EntityResolver

Write data- or field-oriented XML.

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.

Also see:

XMLWriter

since: 1.0 -

author: David - Megginson, david@megginson.com

Constructor:

Constructor:
public DataWriter(Writer writer) { this( writer, null, DumbEscapeHandler.theInstance ); }
public DataWriter(Writer writer, String encoding) { this( writer, encoding, DumbEscapeHandler.theInstance ); }
public DataWriter(Writer writer, String encoding, CharacterEscapeHandler _escapeHandler) { super(writer,encoding,_escapeHandler); } Create a new data writer for the specified output. Parameters: `writer` - The character stream where the XML document will be written. `encoding` - If non-null string is specified, it is written as a part of the XML declaration.

 public DataWriter(Writer writer) {
        this( writer, null, DumbEscapeHandler.theInstance );
}

 public DataWriter(Writer writer,
    String encoding) {
        this( writer, encoding, DumbEscapeHandler.theInstance );
}

 public DataWriter(Writer writer,
    String encoding,
    CharacterEscapeHandler _escapeHandler) {
        super(writer,encoding,_escapeHandler);
}

Create a new data writer for the specified output.

Parameters:

writer - The character stream where the XML document will be written.

encoding - If non-null string is specified, it is written as a part of the XML declaration.

Method from com.sun.xml.internal.txw2.output.DataWriter Summary:
characters, comment, endElement, getIndentStep, reset, setIndentStep, setIndentStep, startElement

Methods from com.sun.xml.internal.txw2.output.XMLWriter:
characters, characters, comment, dataElement, dataElement, dataElement, endCDATA, endDTD, endDocument, endElement, endElement, endElement, endEntity, flush, ignorableWhitespace, processingInstruction, reset, setEncoding, setHeader, setOutput, setXmlDecl, startCDATA, startDTD, startDocument, startElement, startElement, startElement, startEntity, startPrefixMapping

Methods from org.xml.sax.helpers.XMLFilterImpl:
characters, endDocument, endElement, endPrefixMapping, error, fatalError, getContentHandler, getDTDHandler, getEntityResolver, getErrorHandler, getFeature, getParent, getProperty, ignorableWhitespace, notationDecl, parse, parse, processingInstruction, resolveEntity, setContentHandler, setDTDHandler, setDocumentLocator, setEntityResolver, setErrorHandler, setFeature, setParent, setProperty, skippedEntity, startDocument, startElement, startPrefixMapping, unparsedEntityDecl, warning

Methods from org.xml.sax.helpers.XMLFilterImpl:

characters, endDocument, endElement, endPrefixMapping, error, fatalError, getContentHandler, getDTDHandler, getEntityResolver, getErrorHandler, getFeature, getParent, getProperty, ignorableWhitespace, notationDecl, parse, parse, processingInstruction, resolveEntity, setContentHandler, setDTDHandler, setDocumentLocator, setEntityResolver, setErrorHandler, setFeature, setParent, setProperty, skippedEntity, startDocument, startElement, startPrefixMapping, unparsedEntityDecl, warning

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from com.sun.xml.internal.txw2.output.DataWriter Detail:
public void characters(char[] ch, int start, int length) throws SAXException { state = SEEN_DATA; super.characters(ch, start, length); } Write a sequence of characters.
public void comment(char[] ch, int start, int length) throws SAXException { if (depth > 0) { super.characters("\n"); } doIndent(); super.comment(ch,start,length); }
public void endElement(String uri, String localName, String qName) throws SAXException { depth--; if (state == SEEN_ELEMENT) { super.characters("\n"); doIndent(); } super.endElement(uri, localName, qName); state = stateStack.pop(); } Write an end tag. 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.
public int getIndentStep() { return indentStep.length(); } Deprecated! `Only` - return the length of the indent string. Return the current indent step. 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.
public void reset() { depth = 0; state = SEEN_NOTHING; stateStack = new Stack(); super.reset(); } Reset the writer so that it can be reused. This method is especially useful if the writer failed with an exception the last time through.
public void setIndentStep(int indentStep) { StringBuilder s = new StringBuilder(); for( ; indentStep >0; indentStep-- ) s.append(' "); setIndentStep(s.toString()); } Deprecated! `Should` - use the version that takes string. Set the current indent step.
public void setIndentStep(String s) { this.indentStep = s; }
public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException { stateStack.push(SEEN_ELEMENT); state = SEEN_NOTHING; if (depth > 0) { super.characters("\n"); } doIndent(); super.startElement(uri, localName, qName, atts); depth++; } Write a start tag. 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.

Method from com.sun.xml.internal.txw2.output.DataWriter Detail:

 public  void characters(char[] ch,
    int start,
    int length) throws SAXException {
        state = SEEN_DATA;
        super.characters(ch, start, length);
}

Write a sequence of characters.

 public  void comment(char[] ch,
    int start,
    int length) throws SAXException {
        if (depth  > 0) {
            super.characters("\n");
        }
        doIndent();
        super.comment(ch,start,length);
}

 public  void endElement(String uri,
    String localName,
    String qName) throws SAXException {
        depth--;
        if (state == SEEN_ELEMENT) {
            super.characters("\n");
            doIndent();
        }
        super.endElement(uri, localName, qName);
        state = stateStack.pop();
}

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.

 public int getIndentStep() {
        return indentStep.length();
}

Deprecated! Only - return the length of the indent string.

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.

 public  void reset() {
        depth = 0;
        state = SEEN_NOTHING;
        stateStack = new Stack();
        super.reset();
}

This method is especially useful if the writer failed with an exception the last time through.

 public  void setIndentStep(int indentStep) {
        StringBuilder s = new StringBuilder();
        for( ; indentStep >0; indentStep-- )   s.append(' ");
        setIndentStep(s.toString());
}

Deprecated! Should - use the version that takes string.

Set the current indent step.

 public  void setIndentStep(String s) {
        this.indentStep = s;
}

 public  void startElement(String uri,
    String localName,
    String qName,
    Attributes atts) throws SAXException {
        stateStack.push(SEEN_ELEMENT);
        state = SEEN_NOTHING;
        if (depth  > 0) {
            super.characters("\n");
        }
        doIndent();
        super.startElement(uri, localName, qName, atts);
        depth++;
}

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.