public class

CachingParserPool

extends Object
java.lang.Object
   ↳ org.apache.xerces.parsers.CachingParserPool

Class Overview

A parser pool that enables caching of grammars. The caching parser pool is constructed with a specific symbol table and grammar pool that has already been populated with the grammars used by the application.

Once the caching parser pool is constructed, specific parser instances are created by calling the appropriate factory method on the parser pool.

Note: There is a performance penalty for using a caching parser pool due to thread safety. Access to the symbol table and grammar pool must be synchronized to ensure the safe operation of the symbol table and grammar pool.

Note: If performance is critical, then another mechanism needs to be used instead of the caching parser pool. One approach would be to create parser instances that do not share these structures. Instead, each instance would get its own copy to use while parsing. This avoids the synchronization overhead at the expense of more memory and the time required to copy the structures for each new parser instance. And even when a parser instance is re-used, there is a potential for a memory leak due to new symbols being added to the symbol table over time. In other words, always take caution to make sure that your application is thread-safe and avoids leaking memory.

Summary

Nested Classes
class CachingParserPool.ShadowedGrammarPool Shadowed grammar pool. 
class CachingParserPool.SynchronizedGrammarPool Synchronized grammar pool. 
Constants
boolean DEFAULT_SHADOW_GRAMMAR_POOL Default shadow grammar pool (false).
boolean DEFAULT_SHADOW_SYMBOL_TABLE Default shadow symbol table (false).
Fields
protected boolean fShadowGrammarPool Shadow the grammar pool for new parser instances.
protected boolean fShadowSymbolTable Shadow the symbol table for new parser instances.
protected XMLGrammarPool fSynchronizedGrammarPool Grammar pool.
protected SymbolTable fSynchronizedSymbolTable Symbol table.
Public Constructors
CachingParserPool()
Default constructor.
CachingParserPool(SymbolTable symbolTable, XMLGrammarPool grammarPool)
Constructs a caching parser pool with the specified symbol table and grammar pool.
Public Methods
DOMParser createDOMParser()
Creates a new DOM parser.
SAXParser createSAXParser()
Creates a new SAX parser.
SymbolTable getSymbolTable()
Returns the symbol table.
XMLGrammarPool getXMLGrammarPool()
Returns the grammar pool.
void setShadowSymbolTable(boolean shadow)
Sets whether new parser instance receive shadow copies of the main symbol table.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final boolean DEFAULT_SHADOW_GRAMMAR_POOL

Default shadow grammar pool (false).

Constant Value: false

public static final boolean DEFAULT_SHADOW_SYMBOL_TABLE

Default shadow symbol table (false).

Constant Value: false

Fields

protected boolean fShadowGrammarPool

Shadow the grammar pool for new parser instances. If true, new parser instances use shadow copies of the main grammar pool and are not allowed to add new grammars to the main grammar pool. New grammars are added to the shadow grammar pool and are local to the parser instance.

protected boolean fShadowSymbolTable

Shadow the symbol table for new parser instances. If true, new parser instances use shadow copies of the main symbol table and are not allowed to add new symbols to the main symbol table. New symbols are added to the shadow symbol table and are local to the parser instance.

protected XMLGrammarPool fSynchronizedGrammarPool

Grammar pool. The grammar pool that the caching parser pool is constructed with is automatically wrapped in a synchronized version for thread-safety.

protected SymbolTable fSynchronizedSymbolTable

Symbol table. The symbol table that the caching parser pool is constructed with is automatically wrapped in a synchronized version for thread-safety.

Public Constructors

public CachingParserPool ()

Default constructor.

public CachingParserPool (SymbolTable symbolTable, XMLGrammarPool grammarPool)

Constructs a caching parser pool with the specified symbol table and grammar pool.

Parameters
symbolTable The symbol table.
grammarPool The grammar pool.

Public Methods

public DOMParser createDOMParser ()

Creates a new DOM parser.

public SAXParser createSAXParser ()

Creates a new SAX parser.

public SymbolTable getSymbolTable ()

Returns the symbol table.

public XMLGrammarPool getXMLGrammarPool ()

Returns the grammar pool.

public void setShadowSymbolTable (boolean shadow)

Sets whether new parser instance receive shadow copies of the main symbol table.

Parameters
shadow If true, new parser instances use shadow copies of the main symbol table and are not allowed to add new symbols to the main symbol table. New symbols are added to the shadow symbol table and are local to the parser instance. If false, new parser instances are allowed to add new symbols to the main symbol table.