## org.apache.xerces.util
Class NamespaceSupport

    java.lang.Object
      org.apache.xerces.util.NamespaceSupport

All Implemented Interfaces:
  org.apache.xerces.xni.NamespaceContext

Direct Known Subclasses:
  MultipleScopeNamespaceSupport, SchemaNamespaceSupport

    public class NamespaceSupport

extends java.lang.Object
implements org.apache.xerces.xni.NamespaceContext

Namespace support for XML document handlers. This class doesn't perform any error checking and assumes that all strings passed as arguments to methods are unique symbols. The SymbolTable class can be used for this purpose.

Version:
  $Id: NamespaceSupport.java 447241 2006-09-18 05:12:57Z mrglavas $
Author:
  Andy Clark, IBM

Nested Class Summary
`protected class` `NamespaceSupport.Prefixes`

Field Summary
`protected int[]` `fContext` Context indexes.
`protected int` `fCurrentContext` The current context.
`protected java.lang.String[]` `fNamespace` Namespace binding information.
`protected int` `fNamespaceSize` The top of the namespace information array.
`protected java.lang.String[]` `fPrefixes`

Fields inherited from interface org.apache.xerces.xni.NamespaceContext
`XML_URI, XMLNS_URI`

Constructor Summary
`NamespaceSupport()` Default constructor.
`NamespaceSupport(org.apache.xerces.xni.NamespaceContext context)` Constructs a namespace context object and initializes it with the prefixes declared in the specified context.

Method Summary
`boolean` `containsPrefix(java.lang.String prefix)` Checks whether a binding or unbinding for the given prefix exists in the context.
`boolean` `declarePrefix(java.lang.String prefix, java.lang.String uri)` Declare a Namespace prefix.
`java.util.Enumeration` `getAllPrefixes()` Return an enumeration of all prefixes whose declarations are active in the current context.
`java.lang.String` `getDeclaredPrefixAt(int index)` Returns the prefix at the specified index in the current context.
`int` `getDeclaredPrefixCount()` Return a count of locally declared prefixes, including the default prefix if bound.
`java.lang.String` `getPrefix(java.lang.String uri)` Look up a namespace URI and get one of the mapped prefix.
`java.lang.String` `getURI(java.lang.String prefix)` Look up a prefix and get the currently-mapped Namespace URI.
`void` `popContext()` Revert to the previous Namespace context.
`void` `pushContext()` Start a new Namespace context.
`void` `reset()` Reset this Namespace support object for reuse.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### fNamespace

    protected java.lang.String[] fNamespace

  Namespace binding information. This array is composed of a series of tuples containing the namespace binding information: <prefix, uri>. The default size can be set to anything as long as it is a power of 2 greater than 1.

  See Also:
    `fNamespaceSize`, `fContext`

### fNamespaceSize

    protected int fNamespaceSize

  The top of the namespace information array.

### fContext

    protected int[] fContext

  Context indexes. This array contains indexes into the namespace information array. The index at the current context is the start index of declared namespace bindings and runs to the size of the namespace information array.

  See Also:
    `fNamespaceSize`

### fCurrentContext

    protected int fCurrentContext

  The current context.

### fPrefixes

    protected java.lang.String[] fPrefixes

Constructor Detail

### NamespaceSupport

    public NamespaceSupport()

  Default constructor.

### NamespaceSupport

    public NamespaceSupport(org.apache.xerces.xni.NamespaceContext context)

  Constructs a namespace context object and initializes it with the prefixes declared in the specified context.

Method Detail

### reset

    public void reset()

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Reset this Namespace support object for reuse.

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

  Note that implementations of this method need to ensure that the declaration of the prefixes "xmlns" and "xml" are available.

  Specified by:
    `reset` in interface `org.apache.xerces.xni.NamespaceContext`
  See Also:
    `NamespaceContext.reset()`

### pushContext

    public void pushContext()

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Start a new Namespace context.

  A new context should be pushed 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.

  Specified by:
    `pushContext` in interface `org.apache.xerces.xni.NamespaceContext`
  See Also:
    `NamespaceContext.pushContext()`

### popContext

    public void popContext()

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Revert to the previous Namespace context.

  The context should be popped at the end of each XML element. After popping the context, all Namespace prefix mappings that were previously in force are restored.

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

  Specified by:
    `popContext` in interface `org.apache.xerces.xni.NamespaceContext`
  See Also:
    `NamespaceContext.popContext()`

### declarePrefix

    public boolean declarePrefix(java.lang.String prefix,
                                 java.lang.String uri)

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  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.

  Note that to declare a default Namespace, use the empty string. The prefixes "xml" and "xmlns" can't be rebound.

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

  Specified by:
    `declarePrefix` in interface `org.apache.xerces.xni.NamespaceContext`
  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
  See Also:
    `NamespaceContext.declarePrefix(String, String)`

### getURI

    public java.lang.String getURI(java.lang.String prefix)

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Look up a prefix and get the currently-mapped Namespace URI.

  This method looks up the prefix in the current context. If no mapping is found, this methods will continue lookup in the parent context(s). Use the empty string ("") for the default Namespace.

  Specified by:
    `getURI` in interface `org.apache.xerces.xni.NamespaceContext`
  Parameters:
    `prefix` - The prefix to look up.
  Returns:
    The associated Namespace URI, or null if the prefix is undeclared in this context.
  See Also:
    `NamespaceContext.getURI(String)`

### getPrefix

    public java.lang.String getPrefix(java.lang.String uri)

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Look up a namespace URI and get one of the mapped prefix.

  This method looks up the namespace URI in the current context. If more than one prefix is currently mapped to the same URI, this method will make an arbitrary selection If no mapping is found, this methods will continue lookup in the parent context(s).

  Specified by:
    `getPrefix` in interface `org.apache.xerces.xni.NamespaceContext`
  Parameters:
    `uri` - The namespace URI to look up.
  Returns:
    One of the associated prefixes, or null if the uri does not map to any prefix.
  See Also:
    `NamespaceContext.getPrefix(String)`

### getDeclaredPrefixCount

    public int getDeclaredPrefixCount()

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Return a count of locally declared prefixes, including the default prefix if bound.

  Specified by:
    `getDeclaredPrefixCount` in interface `org.apache.xerces.xni.NamespaceContext`
  See Also:
    `NamespaceContext.getDeclaredPrefixCount()`

### getDeclaredPrefixAt

    public java.lang.String getDeclaredPrefixAt(int index)

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Returns the prefix at the specified index in the current context.

  Specified by:
    `getDeclaredPrefixAt` in interface `org.apache.xerces.xni.NamespaceContext`
  See Also:
    `NamespaceContext.getDeclaredPrefixAt(int)`

### getAllPrefixes

    public java.util.Enumeration getAllPrefixes()

  Description copied from interface: `org.apache.xerces.xni.NamespaceContext`
  Return an enumeration of all prefixes whose declarations are active in the current context. This includes declarations from parent contexts that have not been overridden.

  Specified by:
    `getAllPrefixes` in interface `org.apache.xerces.xni.NamespaceContext`
  Returns:
    Enumeration
  See Also:
    `NamespaceContext.getAllPrefixes()`

### containsPrefix

    public boolean containsPrefix(java.lang.String prefix)

  Checks whether a binding or unbinding for the given prefix exists in the context.

  Parameters:
    `prefix` - The prefix to look up.
  Returns:
    true if the given prefix exists in the context

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