Class NamespaceSupport2
This class is an attempt to rewrite the SAX NamespaceSupport "helper" class for improved efficiency. It can be used to track the namespace declarations currently in scope, providing lookup routines to map prefixes to URIs and vice versa.
ISSUE: For testing purposes, I've extended NamespaceSupport even though I'm completely reasserting all behaviors and fields. Wasteful.... But SAX did not put an interface under that object and we seem to have written that SAX class into our APIs... and I don't want to argue with it right now.
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Field Summary
FieldsFields inherited from class org.xml.sax.helpers.NamespaceSupport
NSDECL
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionboolean
declarePrefix
(String prefix, String uri) Declare a Namespace prefix.Return an enumeration of all prefixes declared in this context.Return one of the prefixes mapped to a Namespace URI.Return an enumeration of all prefixes currently declared.getPrefixes
(String uri) Return an enumeration of all prefixes currently declared for a URI.Look up a prefix and get the currently-mapped Namespace URI.void
Revert to the previous Namespace context.String[]
processName
(String qName, String[] parts, boolean isAttribute) Process a raw XML 1.0 name.void
Start a new Namespace context.void
reset()
Reset this Namespace support object for reuse.Methods inherited from class org.xml.sax.helpers.NamespaceSupport
isNamespaceDeclUris, setNamespaceDeclUris
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Field Details
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XMLNS
The XML Namespace as a constant.This is the Namespace URI that is automatically mapped to the "xml" prefix.
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Constructor Details
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NamespaceSupport2
public NamespaceSupport2()Create a new Namespace support object.
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Method Details
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reset
public void reset()Reset this Namespace support object for reuse.It is necessary to invoke this method before reusing the Namespace support object for a new session.
- Overrides:
reset
in classNamespaceSupport
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pushContext
public void pushContext()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.
- Overrides:
pushContext
in classNamespaceSupport
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popContext
public void popContext()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.
- Overrides:
popContext
in classNamespaceSupport
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declarePrefix
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
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 usinggetURI
. This asymmetry exists to make it easier to look up prefixes for attribute names, where the default prefix is not allowed.- Overrides:
declarePrefix
in classNamespaceSupport
- Parameters:
prefix
- The prefix to declare, or null for the empty string.uri
- The Namespace URI to associate with the prefix.- Returns:
- true if the prefix was legal, false otherwise
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processName
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.
- Overrides:
processName
in classNamespaceSupport
- Parameters:
qName
- The raw XML 1.0 name to be processed.parts
- A string array supplied by the caller, capable of holding at least three members.isAttribute
- A flag indicating whether this is an attribute name (true) or an element name (false).- Returns:
- 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.
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getURI
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.
- Overrides:
getURI
in classNamespaceSupport
- Parameters:
prefix
- The prefix to look up.- Returns:
- The associated Namespace URI, or null if the prefix is undeclared in this context.
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getPrefixes
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
getURI
with an argument of "".- Overrides:
getPrefixes
in classNamespaceSupport
- Returns:
- An enumeration of all prefixes declared in the current context except for the empty (default) prefix.
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getPrefix
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
getPrefixes()
method instead.Note: this will never return the empty (default) prefix; to check for a default prefix, use the
getURI
method with an argument of "".- Overrides:
getPrefix
in classNamespaceSupport
- Parameters:
uri
- The Namespace URI.- Returns:
- 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.
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getPrefixes
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
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
getURI
method with an argument of "".- Overrides:
getPrefixes
in classNamespaceSupport
- Parameters:
uri
- The Namespace URI.- Returns:
- An enumeration of all prefixes declared in the current context.
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getDeclaredPrefixes
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
getPrefix(java.lang.String)
andgetPrefixes()
.- Overrides:
getDeclaredPrefixes
in classNamespaceSupport
- Returns:
- An enumeration of all prefixes declared in this context.
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