From 68b16280c97b4ebabda6e3f26d3f3462f557ab8f Mon Sep 17 00:00:00 2001 From: tromey Date: Fri, 20 Dec 2002 03:49:20 +0000 Subject: 2002-12-19 Anthony Green * Makefile.am (ordinary_java_source_files): Add org/xml/sax/helpers/NewInstance.java. * Makefile.in: Rebuilt. * org/xml/sax/package.html, org/xml/sax/ext/package.html, org/xml/sax/helpers/package.html: New files. * org/xml/sax/*: Upgrade to SAX 2.0.1 release from http://www.saxproject.org. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@60350 138bc75d-0d04-0410-961f-82ee72b054a4 --- libjava/org/xml/sax/helpers/XMLReaderFactory.java | 339 +++++++++++++--------- 1 file changed, 203 insertions(+), 136 deletions(-) (limited to 'libjava/org/xml/sax/helpers/XMLReaderFactory.java') diff --git a/libjava/org/xml/sax/helpers/XMLReaderFactory.java b/libjava/org/xml/sax/helpers/XMLReaderFactory.java index 9443b27dcca..e1fa80c84cf 100644 --- a/libjava/org/xml/sax/helpers/XMLReaderFactory.java +++ b/libjava/org/xml/sax/helpers/XMLReaderFactory.java @@ -1,136 +1,203 @@ -// XMLReaderFactory.java - factory for creating a new reader. -// Written by David Megginson, sax@megginson.com -// NO WARRANTY! This class is in the Public Domain. - -// $Id: XMLReaderFactory.java,v 1.1 2000/10/02 02:43:20 sboag Exp $ - -package org.xml.sax.helpers; -import org.xml.sax.Parser; -import org.xml.sax.XMLReader; -import org.xml.sax.SAXException; - - -/** - * Factory for creating an XML reader. - * - *
- * This module, both source code and documentation, is in the - * Public Domain, and comes with NO WARRANTY. - *
- * - *

This class contains static methods for creating an XML reader - * from an explicit class name, or for creating an XML reader based - * on the value of the org.xml.sax.driver system - * property:

- * - * 
- * try {
- *   XMLReader myReader = XMLReaderFactory.createXMLReader();
- * } catch (SAXException e) {
- *   System.err.println(e.getMessage());
- * }
- *
- * - *

Note that these methods will not be usable in environments where - * system properties are not accessible or where the application or - * applet is not permitted to load classes dynamically.

- * - *

Note to implementors: SAX implementations in specialized - * environments may replace this class with a different one optimized for the - * environment, as long as its method signatures remain the same.

- * - * @since SAX 2.0 - * @author David Megginson, - * sax@megginson.com - * @version 2.0 - * @see org.xml.sax.XMLReader - */ -final public class XMLReaderFactory -{ - - /** - * Private constructor. - * - *

This constructor prevents the class from being instantiated.

- */ - private XMLReaderFactory () - { - } - - - /** - * Attempt to create an XML reader from a system property. - * - *

This method uses the value of the system property - * "org.xml.sax.driver" as the full name of a Java class - * and tries to instantiate that class as a SAX2 - * XMLReader.

- * - *

Note that many Java interpreters allow system properties - * to be specified on the command line.

- * - * @return A new XMLReader. - * @exception org.xml.sax.SAXException If the value of the - * "org.xml.sax.driver" system property is null, - * or if the class cannot be loaded and instantiated. - * @see #createXMLReader(java.lang.String) - */ - public static XMLReader createXMLReader () - throws SAXException - { - String className = System.getProperty("org.xml.sax.driver"); - if (className == null) { - Parser parser; - try { - parser = ParserFactory.makeParser(); - } catch (Exception e) { - parser = null; - } - if (parser == null) { - throw new - SAXException("System property org.xml.sax.driver not specified"); - } else { - return new ParserAdapter(parser); - } - } else { - return createXMLReader(className); - } - } - - - /** - * Attempt to create an XML reader from a class name. - * - *

Given a class name, this method attempts to load - * and instantiate the class as an XML reader.

- * - * @return A new XML reader. - * @exception org.xml.sax.SAXException If the class cannot be - * loaded, instantiated, and cast to XMLReader. - * @see #createXMLReader() - */ - public static XMLReader createXMLReader (String className) - throws SAXException - { - try { - return (XMLReader)(Class.forName(className).newInstance()); - } catch (ClassNotFoundException e1) { - throw new SAXException("SAX2 driver class " + className + - " not found", e1); - } catch (IllegalAccessException e2) { - throw new SAXException("SAX2 driver class " + className + - " found but cannot be loaded", e2); - } catch (InstantiationException e3) { - throw new SAXException("SAX2 driver class " + className + - " loaded but cannot be instantiated (no empty public constructor?)", - e3); - } catch (ClassCastException e4) { - throw new SAXException("SAX2 driver class " + className + - " does not implement XMLReader", e4); - } - - } - -} - -// end of XMLReaderFactory.java +// XMLReaderFactory.java - factory for creating a new reader. +// http://www.saxproject.org +// Written by David Megginson +// and by David Brownell +// NO WARRANTY! This class is in the Public Domain. + +// $Id: XMLReaderFactory.java,v 1.5.2.4 2002/01/29 21:34:15 dbrownell Exp $ + +package org.xml.sax.helpers; +import java.io.BufferedReader; +import java.io.InputStream; +import java.io.InputStreamReader; +import org.xml.sax.XMLReader; +import org.xml.sax.SAXException; + + +/** + * Factory for creating an XML reader. + * + *
+ * This module, both source code and documentation, is in the + * Public Domain, and comes with NO WARRANTY. + * See http://www.saxproject.org + * for further information. + *
+ * + *

This class contains static methods for creating an XML reader + * from an explicit class name, or based on runtime defaults:

+ * + * 
+ * try {
+ *   XMLReader myReader = XMLReaderFactory.createXMLReader();
+ * } catch (SAXException e) {
+ *   System.err.println(e.getMessage());
+ * }
+ *
+ * + *

Note to Distributions bundled with parsers: + * You should modify the implementation of the no-arguments + * createXMLReader to handle cases where the external + * configuration mechanisms aren't set up. That method should do its + * best to return a parser when one is in the class path, even when + * nothing bound its class name to org.xml.sax.driver so + * those configuration mechanisms would see it.

+ * + * @since SAX 2.0 + * @author David Megginson, David Brownell + * @version 2.0.1 (sax2r2) + */ +final public class XMLReaderFactory +{ + /** + * Private constructor. + * + *

This constructor prevents the class from being instantiated.

+ */ + private XMLReaderFactory () + { + } + + private static final String property = "org.xml.sax.driver"; + + /** + * Attempt to create an XMLReader from system defaults. + * In environments which can support it, the name of the XMLReader + * class is determined by trying each these options in order, and + * using the first one which succeeds:

+ * + *

In environments such as small embedded systems, which can not + * support that flexibility, other mechanisms to determine the default + * may be used.

+ * + *

Note that many Java environments allow system properties to be + * initialized on a command line. This means that in most cases + * setting a good value for that property ensures that calls to this + * method will succeed, except when security policies intervene. + * This will also maximize application portability to older SAX + * environments, with less robust implementations of this method. + *

+ * + * @return A new XMLReader. + * @exception org.xml.sax.SAXException If no default XMLReader class + * can be identified and instantiated. + * @see #createXMLReader(java.lang.String) + */ + public static XMLReader createXMLReader () + throws SAXException + { + String className = null; + ClassLoader loader = NewInstance.getClassLoader (); + + // 1. try the JVM-instance-wide system property + try { className = System.getProperty (property); } + catch (Exception e) { /* normally fails for applets */ } + + // 2. if that fails, try META-INF/services/ + if (className == null) { + try { + String service = "META-INF/services/" + property; + InputStream in; + BufferedReader reader; + + if (loader == null) + in = ClassLoader.getSystemResourceAsStream (service); + else + in = loader.getResourceAsStream (service); + + if (in != null) { + reader = new BufferedReader ( + new InputStreamReader (in, "UTF8")); + className = reader.readLine (); + in.close (); + } + } catch (Exception e) { + } + } + + // 3. Distro-specific fallback + if (className == null) { +// BEGIN DISTRIBUTION-SPECIFIC + + // EXAMPLE: + // className = "com.example.sax.XmlReader"; + // or a $JAVA_HOME/jre/lib/*properties setting... + +// END DISTRIBUTION-SPECIFIC + } + + // do we know the XMLReader implementation class yet? + if (className != null) + return loadClass (loader, className); + + // 4. panic -- adapt any SAX1 parser + try { + return new ParserAdapter (ParserFactory.makeParser ()); + } catch (Exception e) { + throw new SAXException ("Can't create default XMLReader; " + + "is system property org.xml.sax.driver set?"); + } + } + + + /** + * Attempt to create an XML reader from a class name. + * + *

Given a class name, this method attempts to load + * and instantiate the class as an XML reader.

+ * + *

Note that this method will not be usable in environments where + * the caller (perhaps an applet) is not permitted to load classes + * dynamically.

+ * + * @return A new XML reader. + * @exception org.xml.sax.SAXException If the class cannot be + * loaded, instantiated, and cast to XMLReader. + * @see #createXMLReader() + */ + public static XMLReader createXMLReader (String className) + throws SAXException + { + return loadClass (NewInstance.getClassLoader (), className); + } + + private static XMLReader loadClass (ClassLoader loader, String className) + throws SAXException + { + try { + return (XMLReader) NewInstance.newInstance (loader, className); + } catch (ClassNotFoundException e1) { + throw new SAXException("SAX2 driver class " + className + + " not found", e1); + } catch (IllegalAccessException e2) { + throw new SAXException("SAX2 driver class " + className + + " found but cannot be loaded", e2); + } catch (InstantiationException e3) { + throw new SAXException("SAX2 driver class " + className + + " loaded but cannot be instantiated (no empty public constructor?)", + e3); + } catch (ClassCastException e4) { + throw new SAXException("SAX2 driver class " + className + + " does not implement XMLReader", e4); + } + } +} -- cgit v1.2.3