alma.acs.logging.engine.parser

Class ACSLogParserFactory

java.lang.Object

alma.acs.logging.engine.parser.ACSLogParserFactory

public class ACSLogParserFactory
extends java.lang.Object

A factory to build parsers.

The purpose of this object is to hide the type of parser really used at run time.

The object could instantiate a new parser or use only one instance, a singleton.

There are 2 parsers available: DOM and VTD. VTD is ACS/LGPL/Tools and installed by ACS. It is licensed under GPL and available at http://vtd-xml.sourceforge.net/ VTD claims to be very fast (and effectively it performs better then DOM) so the factory tries to instantiate a VTD parser if it is present.
Having this factory allows to transparently use a different implementation at run-time depending on the real availability of the parsers.

Author:

acaproni

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ACSLogParserFactory.ParserTypes The supported parsers.

Constructor Summary

Constructors

Constructor and Description
ACSLogParserFactory()

Method Summary

Modifier and Type	Method and Description
static ACSLogParser	getParser() Get a parser.
static ACSLogParser	getParser(ACSLogParserFactory.ParserTypes parserType) Get a parser of the given type.
static ACSLogParserFactory.ParserTypes	getParserType() Return the type of the parser in use.
static ACSLogParserFactory.ParserTypes	getParserType(ACSLogParser parserToCheck) Return the type of the passed parser.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ACSLogParserFactory

public ACSLogParserFactory()

Method Detail

getParser

public static ACSLogParser getParser()
                              throws java.lang.Exception

Get a parser.

The ACSLogParser returned by this method can be a new instance or not, depending on the implementation.

Returns:

The parser.

Throws:

Exception - in case of error building the parser

java.lang.Exception

getParser

public static ACSLogParser getParser(ACSLogParserFactory.ParserTypes parserType)
                              throws java.lang.Exception

Get a parser of the given type.

This method allows to get a parser of a specific type and is thought for testing purposes.

If the type of the requested parser is not the type of the parser in use then a new parser is instantiated and returned but the parser in use remains untouched.

Parameters:

parserType - The type of the parser to instantiate. It can't be null.

Returns:

The parser of the given type

Throws:

<{@link - Exception} in case of error instantiating the parser.

java.lang.Exception

getParserType

public static ACSLogParserFactory.ParserTypes getParserType(ACSLogParser parserToCheck)
                                                     throws java.lang.Exception

Return the type of the passed parser.

Parameters:

parser - The parser whose type has to be checked. It can't be null.

Returns:

The type of the parser.

Throws:

java.lang.Exception

getParserType

public static ACSLogParserFactory.ParserTypes getParserType()
                                                     throws java.lang.Exception

Return the type of the parser in use.

Returns:

The type of the parser in use or null if no parser is still in use i.e. getParser() has not been executed yet.

Throws:

java.lang.Exception