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XMLGrammarPool.javaAPI DocApache Xerces 3.0.14607Fri Sep 14 20:33:54 BST 2007org.apache.xerces.xni.grammars

XMLGrammarPool

public interface XMLGrammarPool

This interface specifies how the parser and the application interact with respect to Grammar objects that the application possesses--either by having precompiled them or by having stored them from a previous validation of an instance document. It makes no assumptions about the kind of Grammar involved, or about how the application's storage mechanism works.

The interaction works as follows:

  • When a validator considers a document, it is expected to request grammars of the type it can handle from this object using the retrieveInitialGrammarSet method.
  • If it requires a grammar not in this set, it will request it from this Object using the retrieveGrammar method.
  • After successfully validating an instance, the validator should make any new grammars it has compiled available to this object using the cacheGrammars method; for ease of implementation it may make other Grammars it holds references to as well (i.e., it may return some grammars that were retrieved from the GrammarPool in earlier operations).

author
Neil Graham, IBM
version
$Id: XMLGrammarPool.java 447245 2006-09-18 05:22:10Z mrglavas $

Fields Summary
Constructors Summary
Methods Summary
public voidcacheGrammars(java.lang.String grammarType, Grammar[] grammars)

return the final set of grammars that the validator ended up with. This method is called after the validation finishes. The application may then choose to cache some of the returned grammars.

param
grammarType the type of the grammars being returned;
param
grammars an array containing the set of grammars being returned; order is not significant.

public voidclear()
Removes all grammars from the pool.

public voidlockPool()
Causes the XMLGrammarPool not to store any grammars when the cacheGrammars(String, Grammar[[]) method is called.

public GrammarretrieveGrammar(XMLGrammarDescription desc)

This method requests that the application retrieve a grammar corresponding to the given GrammarIdentifier from its cache. If it cannot do so it must return null; the parser will then call the EntityResolver. An application must not call its EntityResolver itself from this method; this may result in infinite recursions.

param
desc The description of the Grammar being requested.
return
the Grammar corresponding to this description or null if no such Grammar is known.

public Grammar[]retrieveInitialGrammarSet(java.lang.String grammarType)

retrieve the initial known set of grammars. this method is called by a validator before the validation starts. the application can provide an initial set of grammars available to the current validation attempt.

param
grammarType the type of the grammar, from the org.apache.xerces.xni.grammars.Grammar interface.
return
the set of grammars the validator may put in its "bucket"

public voidunlockPool()
Allows the XMLGrammarPool to store grammars when its cacheGrammars(String, Grammar[]) method is called. This is the default state of the object.