From 74b27b64774a3fef2d2bb53bc48a54776cd71bde Mon Sep 17 00:00:00 2001 From: green Date: Wed, 11 Jul 2001 03:59:16 +0000 Subject: Add some org packages. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43922 138bc75d-0d04-0410-961f-82ee72b054a4 --- libjava/org/xml/sax/helpers/NamespaceSupport.java | 689 ++++++++++++++++++++++ 1 file changed, 689 insertions(+) create mode 100644 libjava/org/xml/sax/helpers/NamespaceSupport.java (limited to 'libjava/org/xml/sax/helpers/NamespaceSupport.java') diff --git a/libjava/org/xml/sax/helpers/NamespaceSupport.java b/libjava/org/xml/sax/helpers/NamespaceSupport.java new file mode 100644 index 00000000000..a4588c3d2c7 --- /dev/null +++ b/libjava/org/xml/sax/helpers/NamespaceSupport.java @@ -0,0 +1,689 @@ +// NamespaceSupport.java - generic Namespace support for SAX. +// Written by David Megginson, sax@megginson.com +// This class is in the Public Domain. NO WARRANTY! + +// $Id: NamespaceSupport.java,v 1.1 2000/10/02 02:43:20 sboag Exp $ + +package org.xml.sax.helpers; + +import java.util.EmptyStackException; +import java.util.Enumeration; +import java.util.Hashtable; +import java.util.Vector; + + +/** + * Encapsulate Namespace logic for use by SAX drivers. + * + *
+ * This module, both source code and documentation, is in the + * Public Domain, and comes with NO WARRANTY. + *
+ * + *

This class encapsulates the logic of Namespace processing: + * it tracks the declarations currently in force for each context + * and automatically processes qualified XML 1.0 names into their + * Namespace parts; it can also be used in reverse for generating + * XML 1.0 from Namespaces.

+ * + *

Namespace support objects are reusable, but the reset method + * must be invoked between each session.

+ * + *

Here is a simple session:

+ * + * 
+ * String parts[] = new String[3];
+ * NamespaceSupport support = new NamespaceSupport();
+ *
+ * support.pushContext();
+ * support.declarePrefix("", "http://www.w3.org/1999/xhtml");
+ * support.declarePrefix("dc", "http://www.purl.org/dc#");
+ *
+ * String parts[] = support.processName("p", parts, false);
+ * System.out.println("Namespace URI: " + parts[0]);
+ * System.out.println("Local name: " + parts[1]);
+ * System.out.println("Raw name: " + parts[2]);
+
+ * String parts[] = support.processName("dc:title", parts, false);
+ * System.out.println("Namespace URI: " + parts[0]);
+ * System.out.println("Local name: " + parts[1]);
+ * System.out.println("Raw name: " + parts[2]);
+
+ * support.popContext();
+ *
+ * + *

Note that this class is optimized for the use case where most + * elements do not contain Namespace declarations: if the same + * prefix/URI mapping is repeated for each context (for example), this + * class will be somewhat less efficient.

+ * + * @since SAX 2.0 + * @author David Megginson, + * sax@megginson.com + * @version 2.0 + */ +public class NamespaceSupport +{ + + + //////////////////////////////////////////////////////////////////// + // Constants. + //////////////////////////////////////////////////////////////////// + + + /** + * The XML Namespace as a constant. + * + *

This is the Namespace URI that is automatically mapped + * to the "xml" prefix.

+ */ + public final static String XMLNS = + "http://www.w3.org/XML/1998/namespace"; + + + /** + * An empty enumeration. + */ + private final static Enumeration EMPTY_ENUMERATION = + new Vector().elements(); + + + //////////////////////////////////////////////////////////////////// + // Constructor. + //////////////////////////////////////////////////////////////////// + + + /** + * Create a new Namespace support object. + */ + public NamespaceSupport () + { + reset(); + } + + + + //////////////////////////////////////////////////////////////////// + // Context management. + //////////////////////////////////////////////////////////////////// + + + /** + * Reset this Namespace support object for reuse. + * + *

It is necessary to invoke this method before reusing the + * Namespace support object for a new session.

+ */ + public void reset () + { + contexts = new Context[32]; + contextPos = 0; + contexts[contextPos] = currentContext = new Context(); + currentContext.declarePrefix("xml", XMLNS); + } + + + /** + * Start a new Namespace context. + * + *

Normally, you should push a new context at the beginning + * of each XML element: the new context will automatically inherit + * the declarations of its parent context, but it will also keep + * track of which declarations were made within this context.

+ * + *

The Namespace support object always starts with a base context + * already in force: in this context, only the "xml" prefix is + * declared.

+ * + * @see #popContext + */ + public void pushContext () + { + int max = contexts.length; + contextPos++; + + // Extend the array if necessary + if (contextPos >= max) { + Context newContexts[] = new Context[max*2]; + System.arraycopy(contexts, 0, newContexts, 0, max); + max *= 2; + contexts = newContexts; + } + + // Allocate the context if necessary. + currentContext = contexts[contextPos]; + if (currentContext == null) { + contexts[contextPos] = currentContext = new Context(); + } + + // Set the parent, if any. + if (contextPos > 0) { + currentContext.setParent(contexts[contextPos - 1]); + } + } + + + /** + * Revert to the previous Namespace context. + * + *

Normally, you should pop the context at the end of each + * XML element. After popping the context, all Namespace prefix + * mappings that were previously in force are restored.

+ * + *

You must not attempt to declare additional Namespace + * prefixes after popping a context, unless you push another + * context first.

+ * + * @see #pushContext + */ + public void popContext () + { + contextPos--; + if (contextPos < 0) { + throw new EmptyStackException(); + } + currentContext = contexts[contextPos]; + } + + + + //////////////////////////////////////////////////////////////////// + // Operations within a context. + //////////////////////////////////////////////////////////////////// + + + /** + * Declare a Namespace prefix. + * + *

This method declares a prefix in the current Namespace + * context; the prefix will remain in force until this context + * is popped, unless it is shadowed in a descendant context.

+ * + *

To declare a default Namespace, use the empty string. The + * prefix must not be "xml" or "xmlns".

+ * + *

Note that you must not declare a prefix after + * you've pushed and popped another Namespace.

+ * + *

Note that there is an asymmetry in this library: while {@link + * #getPrefix getPrefix} will not return the default "" prefix, + * even if you have declared one; to check for a default prefix, + * you have to look it up explicitly using {@link #getURI getURI}. + * This asymmetry exists to make it easier to look up prefixes + * for attribute names, where the default prefix is not allowed.

+ * + * @param prefix The prefix to declare, or null for the empty + * string. + * @param uri The Namespace URI to associate with the prefix. + * @return true if the prefix was legal, false otherwise + * @see #processName + * @see #getURI + * @see #getPrefix + */ + public boolean declarePrefix (String prefix, String uri) + { + if (prefix.equals("xml") || prefix.equals("xmlns")) { + return false; + } else { + currentContext.declarePrefix(prefix, uri); + return true; + } + } + + + /** + * Process a raw XML 1.0 name. + * + *

This method processes a raw XML 1.0 name in the current + * context by removing the prefix and looking it up among the + * prefixes currently declared. The return value will be the + * array supplied by the caller, filled in as follows:

+ * + *
+ *
parts[0]
+ *
The Namespace URI, or an empty string if none is + * in use.
+ *
parts[1]
+ *
The local name (without prefix).
+ *
parts[2]
+ *
The original raw name.
+ *
+ * + *

All of the strings in the array will be internalized. If + * the raw name has a prefix that has not been declared, then + * the return value will be null.

+ * + *

Note that attribute names are processed differently than + * element names: an unprefixed element name will received the + * default Namespace (if any), while an unprefixed element name + * will not.

+ * + * @param qName The raw XML 1.0 name to be processed. + * @param parts An array supplied by the caller, capable of + * holding at least three members. + * @param isAttribute A flag indicating whether this is an + * attribute name (true) or an element name (false). + * @return The supplied array holding three internalized strings + * representing the Namespace URI (or empty string), the + * local name, and the raw XML 1.0 name; or null if there + * is an undeclared prefix. + * @see #declarePrefix + * @see java.lang.String#intern */ + public String [] processName (String qName, String parts[], + boolean isAttribute) + { + String myParts[] = currentContext.processName(qName, isAttribute); + if (myParts == null) { + return null; + } else { + parts[0] = myParts[0]; + parts[1] = myParts[1]; + parts[2] = myParts[2]; + return parts; + } + } + + + /** + * Look up a prefix and get the currently-mapped Namespace URI. + * + *

This method looks up the prefix in the current context. + * Use the empty string ("") for the default Namespace.

+ * + * @param prefix The prefix to look up. + * @return The associated Namespace URI, or null if the prefix + * is undeclared in this context. + * @see #getPrefix + * @see #getPrefixes + */ + public String getURI (String prefix) + { + return currentContext.getURI(prefix); + } + + + /** + * Return an enumeration of all prefixes currently declared. + * + *

Note: if there is a default prefix, it will not be + * returned in this enumeration; check for the default prefix + * using the {@link #getURI getURI} with an argument of "".

+ * + * @return An enumeration of all prefixes declared in the + * current context except for the empty (default) + * prefix. + * @see #getDeclaredPrefixes + * @see #getURI + */ + public Enumeration getPrefixes () + { + return currentContext.getPrefixes(); + } + + + /** + * Return one of the prefixes mapped to a Namespace URI. + * + *

If more than one prefix is currently mapped to the same + * URI, this method will make an arbitrary selection; if you + * want all of the prefixes, use the {@link #getPrefixes} + * method instead.

+ * + *

Note: this will never return the empty (default) prefix; + * to check for a default prefix, use the {@link #getURI getURI} + * method with an argument of "".

+ * + * @param uri The Namespace URI. + * @param isAttribute true if this prefix is for an attribute + * (and the default Namespace is not allowed). + * @return One of the prefixes currently mapped to the URI supplied, + * or null if none is mapped or if the URI is assigned to + * the default Namespace. + * @see #getPrefixes(java.lang.String) + * @see #getURI + */ + public String getPrefix (String uri) + { + return currentContext.getPrefix(uri); + } + + + /** + * Return an enumeration of all prefixes currently declared for a URI. + * + *

This method returns prefixes mapped to a specific Namespace + * URI. The xml: prefix will be included. If you want only one + * prefix that's mapped to the Namespace URI, and you don't care + * which one you get, use the {@link #getPrefix getPrefix} + * method instead.

+ * + *

Note: the empty (default) prefix is never included + * in this enumeration; to check for the presence of a default + * Namespace, use the {@link #getURI getURI} method with an + * argument of "".

+ * + * @param uri The Namespace URI. + * @return An enumeration of all prefixes declared in the + * current context. + * @see #getPrefix + * @see #getDeclaredPrefixes + * @see #getURI + */ + public Enumeration getPrefixes (String uri) + { + Vector prefixes = new Vector(); + Enumeration allPrefixes = getPrefixes(); + while (allPrefixes.hasMoreElements()) { + String prefix = (String)allPrefixes.nextElement(); + if (uri.equals(getURI(prefix))) { + prefixes.addElement(prefix); + } + } + return prefixes.elements(); + } + + + /** + * Return an enumeration of all prefixes declared in this context. + * + *

The empty (default) prefix will be included in this + * enumeration; note that this behaviour differs from that of + * {@link #getPrefix} and {@link #getPrefixes}.

+ * + * @return An enumeration of all prefixes declared in this + * context. + * @see #getPrefixes + * @see #getURI + */ + public Enumeration getDeclaredPrefixes () + { + return currentContext.getDeclaredPrefixes(); + } + + + + //////////////////////////////////////////////////////////////////// + // Internal state. + //////////////////////////////////////////////////////////////////// + + private Context contexts[]; + private Context currentContext; + private int contextPos; + + + + //////////////////////////////////////////////////////////////////// + // Internal classes. + //////////////////////////////////////////////////////////////////// + + /** + * Internal class for a single Namespace context. + * + *

This module caches and reuses Namespace contexts, so the number allocated + * will be equal to the element depth of the document, not to the total + * number of elements (i.e. 5-10 rather than tens of thousands).

+ */ + final class Context { + + /** + * Create the root-level Namespace context. + */ + Context () + { + copyTables(); + } + + + /** + * (Re)set the parent of this Namespace context. + * + * @param context The parent Namespace context object. + */ + void setParent (Context parent) + { + this.parent = parent; + declarations = null; + prefixTable = parent.prefixTable; + uriTable = parent.uriTable; + elementNameTable = parent.elementNameTable; + attributeNameTable = parent.attributeNameTable; + defaultNS = parent.defaultNS; + tablesDirty = false; + } + + + /** + * Declare a Namespace prefix for this context. + * + * @param prefix The prefix to declare. + * @param uri The associated Namespace URI. + * @see org.xml.sax.helpers.NamespaceSupport#declarePrefix + */ + void declarePrefix (String prefix, String uri) + { + // Lazy processing... + if (!tablesDirty) { + copyTables(); + } + if (declarations == null) { + declarations = new Vector(); + } + + prefix = prefix.intern(); + uri = uri.intern(); + if ("".equals(prefix)) { + if ("".equals(uri)) { + defaultNS = null; + } else { + defaultNS = uri; + } + } else { + prefixTable.put(prefix, uri); + uriTable.put(uri, prefix); // may wipe out another prefix + } + declarations.addElement(prefix); + } + + + /** + * Process a raw XML 1.0 name in this context. + * + * @param qName The raw XML 1.0 name. + * @param isAttribute true if this is an attribute name. + * @return An array of three strings containing the + * URI part (or empty string), the local part, + * and the raw name, all internalized, or null + * if there is an undeclared prefix. + * @see org.xml.sax.helpers.NamespaceSupport#processName + */ + String [] processName (String qName, boolean isAttribute) + { + String name[]; + Hashtable table; + + // Select the appropriate table. + if (isAttribute) { + table = elementNameTable; + } else { + table = attributeNameTable; + } + + // Start by looking in the cache, and + // return immediately if the name + // is already known in this content + name = (String[])table.get(qName); + if (name != null) { + return name; + } + + // We haven't seen this name in this + // context before. + name = new String[3]; + int index = qName.indexOf(':'); + + + // No prefix. + if (index == -1) { + if (isAttribute || defaultNS == null) { + name[0] = ""; + } else { + name[0] = defaultNS; + } + name[1] = qName.intern(); + name[2] = name[1]; + } + + // Prefix + else { + String prefix = qName.substring(0, index); + String local = qName.substring(index+1); + String uri; + if ("".equals(prefix)) { + uri = defaultNS; + } else { + uri = (String)prefixTable.get(prefix); + } + if (uri == null) { + return null; + } + name[0] = uri; + name[1] = local.intern(); + name[2] = qName.intern(); + } + + // Save in the cache for future use. + table.put(name[2], name); + tablesDirty = true; + return name; + } + + + /** + * Look up the URI associated with a prefix in this context. + * + * @param prefix The prefix to look up. + * @return The associated Namespace URI, or null if none is + * declared. + * @see org.xml.sax.helpers.NamespaceSupport#getURI + */ + String getURI (String prefix) + { + if ("".equals(prefix)) { + return defaultNS; + } else if (prefixTable == null) { + return null; + } else { + return (String)prefixTable.get(prefix); + } + } + + + /** + * Look up one of the prefixes associated with a URI in this context. + * + *

Since many prefixes may be mapped to the same URI, + * the return value may be unreliable.

+ * + * @param uri The URI to look up. + * @return The associated prefix, or null if none is declared. + * @see org.xml.sax.helpers.NamespaceSupport#getPrefix + */ + String getPrefix (String uri) + { + if (uriTable == null) { + return null; + } else { + return (String)uriTable.get(uri); + } + } + + + /** + * Return an enumeration of prefixes declared in this context. + * + * @return An enumeration of prefixes (possibly empty). + * @see org.xml.sax.helpers.NamespaceSupport#getDeclaredPrefixes + */ + Enumeration getDeclaredPrefixes () + { + if (declarations == null) { + return EMPTY_ENUMERATION; + } else { + return declarations.elements(); + } + } + + + /** + * Return an enumeration of all prefixes currently in force. + * + *

The default prefix, if in force, is not + * returned, and will have to be checked for separately.

+ * + * @return An enumeration of prefixes (never empty). + * @see org.xml.sax.helpers.NamespaceSupport#getPrefixes + */ + Enumeration getPrefixes () + { + if (prefixTable == null) { + return EMPTY_ENUMERATION; + } else { + return prefixTable.keys(); + } + } + + + + //////////////////////////////////////////////////////////////// + // Internal methods. + //////////////////////////////////////////////////////////////// + + + /** + * Copy on write for the internal tables in this context. + * + *

This class is optimized for the normal case where most + * elements do not contain Namespace declarations.

+ */ + private void copyTables () + { + if (prefixTable != null) { + prefixTable = (Hashtable)prefixTable.clone(); + } else { + prefixTable = new Hashtable(); + } + if (uriTable != null) { + uriTable = (Hashtable)uriTable.clone(); + } else { + uriTable = new Hashtable(); + } + elementNameTable = new Hashtable(); + attributeNameTable = new Hashtable(); + tablesDirty = true; + } + + + + //////////////////////////////////////////////////////////////// + // Protected state. + //////////////////////////////////////////////////////////////// + + Hashtable prefixTable; + Hashtable uriTable; + Hashtable elementNameTable; + Hashtable attributeNameTable; + String defaultNS = null; + + + + //////////////////////////////////////////////////////////////// + // Internal state. + //////////////////////////////////////////////////////////////// + + private Vector declarations = null; + private boolean tablesDirty = false; + private Context parent = null; + } +} + +// end of NamespaceSupport.java -- cgit v1.2.3