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Posted to commons-cvs@xml.apache.org by mr...@apache.org on 2005/06/21 21:03:17 UTC
cvs commit: xml-commons/java/external/src/org/xml/sax/helpers SecuritySupport12.java SecuritySupport.java XMLReaderFactory.java
mrglavas 2005/06/21 12:03:16
Modified: java/external/src/org/xml/sax/helpers XMLReaderFactory.java
Added: java/external/src/org/xml/sax/helpers SecuritySupport12.java
SecuritySupport.java
Log:
Merging in SecuritySupport code from the tck-jaxp-1_2_0 branch.
Revision Changes Path
1.6 +241 -203 xml-commons/java/external/src/org/xml/sax/helpers/XMLReaderFactory.java
Index: XMLReaderFactory.java
===================================================================
RCS file: /home/cvs/xml-commons/java/external/src/org/xml/sax/helpers/XMLReaderFactory.java,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- XMLReaderFactory.java 8 Apr 2005 10:53:24 -0000 1.5
+++ XMLReaderFactory.java 21 Jun 2005 19:03:16 -0000 1.6
@@ -1,203 +1,241 @@
-// 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.
-// $Id$
-
-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.
- *
- * <blockquote>
- * <em>This module, both source code and documentation, is in the
- * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
- * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
- * for further information.
- * </blockquote>
- *
- * <p>This class contains static methods for creating an XML reader
- * from an explicit class name, or based on runtime defaults:</p>
- *
- * <pre>
- * try {
- * XMLReader myReader = XMLReaderFactory.createXMLReader();
- * } catch (SAXException e) {
- * System.err.println(e.getMessage());
- * }
- * </pre>
- *
- * <p><strong>Note to Distributions bundled with parsers:</strong>
- * You should modify the implementation of the no-arguments
- * <em>createXMLReader</em> 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 <code>org.xml.sax.driver</code> so
- * those configuration mechanisms would see it.</p>
- *
- * @since SAX 2.0
- * @author David Megginson, David Brownell
- * @version 2.0.1 (sax2r2)
- */
-final public class XMLReaderFactory
-{
- /**
- * Private constructor.
- *
- * <p>This constructor prevents the class from being instantiated.</p>
- */
- 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:</p> <ul>
- *
- * <li>If the system property <code>org.xml.sax.driver</code>
- * has a value, that is used as an XMLReader class name. </li>
- *
- * <li>The JAR "Services API" is used to look for a class name
- * in the <em>META-INF/services/org.xml.sax.driver</em> file in
- * jarfiles available to the runtime.</li>
- *
- * <li> SAX parser distributions are strongly encouraged to provide
- * a default XMLReader class name that will take effect only when
- * previous options (on this list) are not successful.</li>
- *
- * <li>Finally, if {@link ParserFactory#makeParser()} can
- * return a system default SAX1 parser, that parser is wrapped in
- * a {@link ParserAdapter}. (This is a migration aid for SAX1
- * environments, where the <code>org.xml.sax.parser</code> system
- * property will often be usable.) </li>
- *
- * </ul>
- *
- * <p> In environments such as small embedded systems, which can not
- * support that flexibility, other mechanisms to determine the default
- * may be used. </p>
- *
- * <p>Note that many Java environments allow system properties to be
- * initialized on a command line. This means that <em>in most cases</em>
- * 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.
- * </p>
- *
- * @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 (RuntimeException 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...
- className = "org.apache.xerces.parsers.SAXParser";
-
-// 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.
- *
- * <p>Given a class name, this method attempts to load
- * and instantiate the class as an XML reader.</p>
- *
- * <p>Note that this method will not be usable in environments where
- * the caller (perhaps an applet) is not permitted to load classes
- * dynamically.</p>
- *
- * @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);
- }
- }
-}
+// 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.
+// $Id$
+
+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.
+ *
+ * <blockquote>
+ * <em>This module, both source code and documentation, is in the
+ * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
+ * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
+ * for further information.
+ * </blockquote>
+ *
+ * <p>This class contains static methods for creating an XML reader
+ * from an explicit class name, or based on runtime defaults:</p>
+ *
+ * <pre>
+ * try {
+ * XMLReader myReader = XMLReaderFactory.createXMLReader();
+ * } catch (SAXException e) {
+ * System.err.println(e.getMessage());
+ * }
+ * </pre>
+ *
+ * <p><strong>Note to Distributions bundled with parsers:</strong>
+ * You should modify the implementation of the no-arguments
+ * <em>createXMLReader</em> 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 <code>org.xml.sax.driver</code> so
+ * those configuration mechanisms would see it.</p>
+ *
+ * @since SAX 2.0
+ * @author David Megginson, David Brownell
+ * @version 2.0.1 (sax2r2)
+ */
+final public class XMLReaderFactory
+{
+ /**
+ * Private constructor.
+ *
+ * <p>This constructor prevents the class from being instantiated.</p>
+ */
+ 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:</p> <ul>
+ *
+ * <li>If the system property <code>org.xml.sax.driver</code>
+ * has a value, that is used as an XMLReader class name. </li>
+ *
+ * <li>The JAR "Services API" is used to look for a class name
+ * in the <em>META-INF/services/org.xml.sax.driver</em> file in
+ * jarfiles available to the runtime.</li>
+ *
+ * <li> SAX parser distributions are strongly encouraged to provide
+ * a default XMLReader class name that will take effect only when
+ * previous options (on this list) are not successful.</li>
+ *
+ * <li>Finally, if {@link ParserFactory#makeParser()} can
+ * return a system default SAX1 parser, that parser is wrapped in
+ * a {@link ParserAdapter}. (This is a migration aid for SAX1
+ * environments, where the <code>org.xml.sax.parser</code> system
+ * property will often be usable.) </li>
+ *
+ * </ul>
+ *
+ * <p> In environments such as small embedded systems, which can not
+ * support that flexibility, other mechanisms to determine the default
+ * may be used. </p>
+ *
+ * <p>Note that many Java environments allow system properties to be
+ * initialized on a command line. This means that <em>in most cases</em>
+ * 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.
+ * </p>
+ *
+ * @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;
+ SecuritySupport ss = SecuritySupport.getInstance();
+ ClassLoader loader = NewInstance.getClassLoader ();
+
+ // 1. try the JVM-instance-wide system property
+ try { className = System.getProperty (property); }
+ catch (RuntimeException e) { /* normally fails for applets */ }
+
+ // 2. if that fails, try META-INF/services/
+ if (className == null) {
+ String service = "META-INF/services/" + property;
+
+ InputStream is = null;
+
+ // First try the Context ClassLoader
+ ClassLoader cl = ss.getContextClassLoader();
+ if (cl != null) {
+ is = ss.getResourceAsStream(cl, service);
+
+ // If no provider found then try the current ClassLoader
+ if (is == null) {
+ cl = XMLReaderFactory.class.getClassLoader();
+ is = ss.getResourceAsStream(cl, service);
+ }
+ } else {
+ // No Context ClassLoader or JDK 1.1 so try the current
+ // ClassLoader
+ cl = XMLReaderFactory.class.getClassLoader();
+ is = ss.getResourceAsStream(cl, service);
+ }
+
+ if (is != null) {
+
+ // Read the service provider name in UTF-8 as specified in
+ // the jar spec. Unfortunately this fails in Microsoft
+ // VJ++, which does not implement the UTF-8
+ // encoding. Theoretically, we should simply let it fail in
+ // that case, since the JVM is obviously broken if it
+ // doesn't support such a basic standard. But since there
+ // are still some users attempting to use VJ++ for
+ // development, we have dropped in a fallback which makes a
+ // second attempt using the platform's default encoding. In
+ // VJ++ this is apparently ASCII, which is a subset of
+ // UTF-8... and since the strings we'll be reading here are
+ // also primarily limited to the 7-bit ASCII range (at
+ // least, in English versions), this should work well
+ // enough to keep us on the air until we're ready to
+ // officially decommit from VJ++. [Edited comment from
+ // jkesselm]
+ BufferedReader rd;
+ try {
+ rd = new BufferedReader(new InputStreamReader(is, "UTF-8"));
+ } catch (java.io.UnsupportedEncodingException e) {
+ rd = new BufferedReader(new InputStreamReader(is));
+ }
+
+ try {
+ // XXX Does not handle all possible input as specified by the
+ // Jar Service Provider specification
+ className = rd.readLine();
+ rd.close();
+ } catch (Exception x) {
+ // No provider found
+ }
+ }
+ }
+
+ // 3. Distro-specific fallback
+ if (className == null) {
+ // BEGIN DISTRIBUTION-SPECIFIC
+
+ // EXAMPLE:
+ // className = "com.example.sax.XmlReader";
+ // or a $JAVA_HOME/jre/lib/*properties setting...
+ className = "org.apache.xerces.parsers.SAXParser";
+
+ // 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.
+ *
+ * <p>Given a class name, this method attempts to load
+ * and instantiate the class as an XML reader.</p>
+ *
+ * <p>Note that this method will not be usable in environments where
+ * the caller (perhaps an applet) is not permitted to load classes
+ * dynamically.</p>
+ *
+ * @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);
+ }
+ }
+}
1.4 +20 -55 xml-commons/java/external/src/org/xml/sax/helpers/SecuritySupport12.java
1.4 +16 -54 xml-commons/java/external/src/org/xml/sax/helpers/SecuritySupport.java