Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

A
DocumentBuilderFactory
is a factory class for creating
DocumentBuilder objects. You can obtain a
DocumentBuilderFactory by instantiating an
implementation-specific subclass provided by a parser vendor, but it
is much more common to simply call newInstance( )
to obtain an instance of the factory that has been configured as the
default for the system. Once you have obtained a factory object, you
can use the various set methods to configure the
properties of the DocumentBuilder objects it will
create. These methods allow you to specify whether the parsers
created by the factory will:

• coalesce CDATA sections with adjacent text nodes;

• expand entity references or leave them unexpanded in the document
  tree;

• omit XML comments from the document tree;

• omit ignorable whitespace from the document tree;

• handle XML namespaces correctly; and

• validate XML documents against a DTD or other schema.

In Java 5.0, you can use setSchema( ) to specify
the javax.xml.vaidation.Schema object against
which parsers should validate their documents. And you can use
setXIncludeAware( ) to indicate that parsers
should process XInclude markup.

In addition to the various implementation-independent
set methods, you can also use
setAttribute( ) pass an implementation-dependent
named attribute to the underlying parser implementation. Once you
have configured the factory object as desired, simply call
newDocumentBuilder( ) to create a
DocumentBuilder object with the all of the
attributes you have specified. Note that
DocumentBuilderFactory objects are not typically
threadsafe.

The javax.xml.parsers package allows parser
implementations to be "plugged in."
This pluggability is provided by the getInstance(
) method, which follows the following steps to determine
which DocumentBuilderFactory implementation to
use:

• If the javax.xml.parsers.DocumentBuilderFactory
  system property is defined, then the class specified by that property
  is used.

• Otherwise, if the

  jre/lib/jaxp.properties file
  exists in the Java distribution and contains a definition for the
  javax.xml.parsers.DocumentBuilderFactory property,
  then the class specified by that property is used.

• Otherwise, if any of the JAR files on the classpath includes a file
  named
  

  META-INF/services/javax.xml.parsers.DocumentBuilderFactory ,
  then the class named in that file will be used.

• Otherwise, a default implementation provided by the Java
  implementation will be used.

DocumentBuilderFactory {
// Protected Constructors
protected

DocumentBuilderFactory ( );
// Public Class Methods
public static DocumentBuilderFactory

newInstance ( );
// Public Instance Methods
public abstract Object

getAttribute (String

name )
throws IllegalArgumentException;

5.0 public abstract boolean

getFeature (String

name )
throws ParserConfigurationException;

5.0 public javax.xml.validation.Schema

getSchema ( );
public boolean

isCoalescing ( );
public boolean

isExpandEntityReferences ( );
public boolean

isIgnoringComments ( );
public boolean

isIgnoringElementContentWhitespace ( );
public boolean

isNamespaceAware ( );
public boolean

isValidating ( );

5.0 public boolean

isXIncludeAware ( );
public abstract DocumentBuilder

newDocumentBuilder ( )
throws ParserConfigurationException;
public abstract void

setAttribute (String

name , Object

value )
throws IllegalArgumentException;
public void

setCoalescing (boolean

coalescing );
public void

setExpandEntityReferences (boolean

expandEntityRef );

5.0 public abstract void

setFeature (String

name , boolean

value )
throws ParserConfigurationException;
public void

setIgnoringComments (boolean

ignoreComments );
public void

setIgnoringElementContentWhitespace (boolean

whitespace );
public void

setNamespaceAware (boolean

awareness );

5.0 public void

setSchema (javax.xml.validation.Schema

schema );
public void

setValidating (boolean

validating );

5.0 public void

setXIncludeAware (boolean

state );
}