org.xmlpull.v1.XmlPullParserFactory Maven / Gradle / Ivy
/*
* XMLPULL API IS FREE
* -------------------
*
* All of the XMLPULL API source code, compiled code, and documentation
* contained in this distribution *except* for tests (see separate LICENSE_TESTS.txt)
* are in the Public Domain.
*
* XMLPULL API comes with NO WARRANTY or guarantee of fitness for any purpose.
*
* Initial authors:
*
* Stefan Haustein
* Aleksander Slominski
*
* 2001-12-12
*/
package org.xmlpull.v1;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
/**
* This class is used to create implementations of XML Pull Parser defined in XMPULL V1 API.
* The name of actual factory class will be determined based on several parameters.
* It works similar to JAXP but tailored to work in J2ME environments
* (no access to system properties or file system) so name of parser class factory to use
* and its class used for loading (no class loader - on J2ME no access to context class loaders)
* must be passed explicitly. If no name of parser factory was passed (or is null)
* it will try to find name by searching in CLASSPATH for
* META-INF/services/org.xmlpull.v1.XmlPullParserFactory resource that should contain
* a comma separated list of class names of factories or parsers to try (in order from
* left to the right). If none found, it will throw an exception.
*
*
NOTE:In J2SE or J2EE environments, you may want to use
* newInstance(property, classLoaderCtx)
* where first argument is
* System.getProperty(XmlPullParserFactory.PROPERTY_NAME)
* and second is Thread.getContextClassLoader().getClass() .
*
* @see XmlPullParser
*
* @author Aleksander Slominski
* @author Stefan Haustein
*/
public class XmlPullParserFactory {
/** used as default class to server as context class in newInstance() */
final static Class referenceContextClass;
static {
XmlPullParserFactory f = new XmlPullParserFactory();
referenceContextClass = f.getClass();
}
/** Name of the system or midlet property that should be used for
a system property containing a comma separated list of factory
or parser class names (value:
org.xmlpull.v1.XmlPullParserFactory). */
public static final String PROPERTY_NAME =
"org.xmlpull.v1.XmlPullParserFactory";
private static final String RESOURCE_NAME =
"/META-INF/services/" + PROPERTY_NAME;
// public static final String DEFAULT_PROPERTY =
// "org.xmlpull.xpp3.XmlPullParser,org.kxml2.io.KXmlParser";
protected Vector parserClasses;
protected String classNamesLocation;
protected Vector serializerClasses;
// features are kept there
protected Hashtable features = new Hashtable();
/**
* Protected constructor to be called by factory implementations.
*/
protected XmlPullParserFactory() {
}
/**
* Set the features to be set when XML Pull Parser is created by this factory.
* NOTE: factory features are not used for XML Serializer.
*
* @param name string with URI identifying feature
* @param state if true feature will be set; if false will be ignored
*/
public void setFeature(String name,
boolean state) throws XmlPullParserException {
features.put(name, new Boolean(state));
}
/**
* Return the current value of the feature with given name.
*
NOTE: factory features are not used for XML Serializer.
*
* @param name The name of feature to be retrieved.
* @return The value of named feature.
* Unknown features are always returned as false
*/
public boolean getFeature (String name) {
Boolean value = (Boolean) features.get(name);
return value != null ? value.booleanValue() : false;
}
/**
* Specifies that the parser produced by this factory will provide
* support for XML namespaces.
* By default the value of this is set to false.
*
* @param awareness true if the parser produced by this code
* will provide support for XML namespaces; false otherwise.
*/
public void setNamespaceAware(boolean awareness) {
features.put (XmlPullParser.FEATURE_PROCESS_NAMESPACES, new Boolean (awareness));
}
/**
* Indicates whether or not the factory is configured to produce
* parsers which are namespace aware
* (it simply set feature XmlPullParser.FEATURE_PROCESS_NAMESPACES to true or false).
*
* @return true if the factory is configured to produce parsers
* which are namespace aware; false otherwise.
*/
public boolean isNamespaceAware() {
return getFeature (XmlPullParser.FEATURE_PROCESS_NAMESPACES);
}
/**
* Specifies that the parser produced by this factory will be validating
* (it simply set feature XmlPullParser.FEATURE_VALIDATION to true or false).
*
* By default the value of this is set to false.
*
* @param validating - if true the parsers created by this factory must be validating.
*/
public void setValidating(boolean validating) {
features.put (XmlPullParser.FEATURE_VALIDATION, new Boolean (validating));
}
/**
* Indicates whether or not the factory is configured to produce parsers
* which validate the XML content during parse.
*
* @return true if the factory is configured to produce parsers
* which validate the XML content during parse; false otherwise.
*/
public boolean isValidating() {
return getFeature (XmlPullParser.FEATURE_VALIDATION);
}
/**
* Creates a new instance of a XML Pull Parser
* using the currently configured factory features.
*
* @return A new instance of a XML Pull Parser.
* @throws XmlPullParserException if a parser cannot be created which satisfies the
* requested configuration.
*/
public XmlPullParser newPullParser() throws XmlPullParserException {
if (parserClasses == null) throw new XmlPullParserException
("Factory initialization was incomplete - has not tried "+classNamesLocation);
if (parserClasses.size() == 0) throw new XmlPullParserException
("No valid parser classes found in "+classNamesLocation);
final StringBuffer issues = new StringBuffer ();
for (int i = 0; i < parserClasses.size (); i++) {
final Class ppClass = (Class) parserClasses.elementAt (i);
try {
final XmlPullParser pp = (XmlPullParser) ppClass.newInstance();
for (Enumeration e = features.keys (); e.hasMoreElements ();) {
final String key = (String) e.nextElement();
final Boolean value = (Boolean) features.get(key);
if(value != null && value.booleanValue()) {
pp.setFeature(key, true);
}
}
return pp;
} catch(Exception ex) {
issues.append (ppClass.getName () + ": "+ ex.toString ()+"; ");
}
}
throw new XmlPullParserException ("could not create parser: "+issues);
}
/**
* Creates a new instance of a XML Serializer.
*
* NOTE: factory features are not used for XML Serializer.
*
* @return A new instance of a XML Serializer.
* @throws XmlPullParserException if a parser cannot be created which satisfies the
* requested configuration.
*/
public XmlSerializer newSerializer() throws XmlPullParserException {
if (serializerClasses == null) {
throw new XmlPullParserException
("Factory initialization incomplete - has not tried "+classNamesLocation);
}
if(serializerClasses.size() == 0) {
throw new XmlPullParserException
("No valid serializer classes found in "+classNamesLocation);
}
final StringBuffer issues = new StringBuffer ();
for (int i = 0; i < serializerClasses.size (); i++) {
final Class ppClass = (Class) serializerClasses.elementAt (i);
try {
final XmlSerializer ser = (XmlSerializer) ppClass.newInstance();
return ser;
} catch(Exception ex) {
issues.append (ppClass.getName () + ": "+ ex.toString ()+"; ");
}
}
throw new XmlPullParserException ("could not create serializer: "+issues);
}
/**
* Create a new instance of a PullParserFactory that can be used
* to create XML pull parsers (see class description for more
* details).
*
* @return a new instance of a PullParserFactory, as returned by newInstance (null, null);
*/
public static XmlPullParserFactory newInstance () throws XmlPullParserException {
return newInstance(null, null);
}
public static XmlPullParserFactory newInstance (String classNames, Class context)
throws XmlPullParserException {
if (context == null) {
//NOTE: make sure context uses the same class loader as API classes
// this is the best we can do without having access to context classloader in J2ME
// if API is in the same classloader as implementation then this will work
context = referenceContextClass;
}
String classNamesLocation = null;
if (classNames == null || classNames.length() == 0 || "DEFAULT".equals(classNames)) {
try {
InputStream is = context.getResourceAsStream (RESOURCE_NAME);
if (is == null) throw new XmlPullParserException
("resource not found: "+RESOURCE_NAME
+" make sure that parser implementing XmlPull API is available");
final StringBuffer sb = new StringBuffer();
while (true) {
final int ch = is.read();
if (ch < 0) break;
else if (ch > ' ')
sb.append((char) ch);
}
is.close ();
classNames = sb.toString ();
}
catch (Exception e) {
throw new XmlPullParserException (null, null, e);
}
classNamesLocation = "resource "+RESOURCE_NAME+" that contained '"+classNames+"'";
} else {
classNamesLocation =
"parameter classNames to newInstance() that contained '"+classNames+"'";
}
XmlPullParserFactory factory = null;
final Vector parserClasses = new Vector ();
final Vector serializerClasses = new Vector ();
int pos = 0;
while (pos < classNames.length ()) {
int cut = classNames.indexOf (',', pos);
if (cut == -1) cut = classNames.length ();
final String name = classNames.substring (pos, cut);
Class candidate = null;
Object instance = null;
try {
candidate = Class.forName (name);
// necessary because of J2ME .class issue
instance = candidate.newInstance ();
}
catch (Exception e) {}
if (candidate != null) {
boolean recognized = false;
if (instance instanceof XmlPullParser) {
parserClasses.addElement (candidate);
recognized = true;
}
if (instance instanceof XmlSerializer) {
serializerClasses.addElement (candidate);
recognized = true;
}
if (instance instanceof XmlPullParserFactory) {
if (factory == null) {
factory = (XmlPullParserFactory) instance;
}
recognized = true;
}
if (!recognized) {
throw new XmlPullParserException ("incompatible class: "+name);
}
}
pos = cut + 1;
}
if (factory == null) {
factory = new XmlPullParserFactory ();
}
factory.parserClasses = parserClasses;
factory.serializerClasses = serializerClasses;
factory.classNamesLocation = classNamesLocation;
return factory;
}
}