com.ibm.di.parser
Class ParserImpl

java.lang.Object
  com.ibm.di.parser.ParserImpl

All Implemented Interfaces:

ParserInterface, VersionInfoInterface

Direct Known Subclasses:

CSVParser, Dsmlv2Parser, FixedRecordParser, HTTPParser, LDIFParser, LineReader, ScriptParser, SimpleParser, XMLParser, XMLParser2, XMLSaxParser, XSLbasedXMLParser

public abstract class ParserImpl
extends Object
implements ParserInterface, VersionInfoInterface

The ParserImpl class provides the base class for parser implementations. This class provides common methods and properties that apply to all parsers.

Field Summary

protected boolean	_debug True if debug is enabled; false otherwise.
protected ParserConfig	myConfiguration The parser's configuration.

Constructor Summary

ParserImpl()
Default constructor.

Method Summary

void	closeParser() Close parser and deallocate resources.
void	debug(String msg) Writes a message to the log if debug mode is set.
boolean	debugMode() Returns current status of the debugMode flag.
void	flush() This method is called by some hosting components to flush any in-memory data to the current output stream.
static Object	getClassInstance(String className) Create a parser instance.
Object	getContext() Return the context in which this parser is running (e.g.
boolean	getDebug() Returns current status of the debugMode flag.
InputStream	getInputStream() Return current input-stream object.
OutputStream	getOutputStream() Return current output-stream object.
String	getParam(String param) Return configuration value.
ParserInterface	getParser() Return the chained parser (future implementation).
BufferedReader	getReader() Return current reader object.
BufferedWriter	getWriter() Return current writer object.
void	initParser() Perform initialization of parser.
boolean	isDeltaSupported() Returns true if this connector is able to perform delta updates
void	logmsg(String msg) Writes a message to the log.
Object	querySchema(Object source) Discover the schema for the Parser.
void	registerScriptBeans(ScriptEngine se) Register objects in the script engine.
void	setConfiguration(ParserConfig config) Set the parser configuration.
void	setContext(Object context) Set the context in which the parser runs.
void	setDebug(boolean debug) Sets the status of the debugMode flag.
void	setInputStream(InputStream is) Set the parser input stream.
void	setInputStream(Reader is) Use Reader object for input.
void	setInputStream(String is) Use a string as input.
void	setOutputStream(OutputStream os) Set the parser output stream.
void	setOutputStream(Writer os) Use Writer object for output.
void	setParam(String param, String value) Set parser configuration value.
void	setParser(ParserInterface parser) Set the chained parser (future implementation).

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.ibm.di.parser.ParserInterface

readEntry, writeEntry

Methods inherited from interface com.ibm.di.server.VersionInfoInterface

getVersion

Field Detail

myConfiguration

protected ParserConfig myConfiguration

The parser's configuration.

_debug

protected volatile boolean _debug

True if debug is enabled; false otherwise. May be accessed by different threads.

Constructor Detail

ParserImpl

public ParserImpl()

Default constructor.

Method Detail

getContext

public Object getContext()

Return the context in which this parser is running (e.g. AssemblyLine object). The context is called upon when the parser needs to access resources outside it's scope. The logmsg method is one such build-in method but sub-classes may use the context object to communicate with the "housing" object. This object is typically a connector. If the object using this class is not setting the context then the return value is null.

Specified by:

getContext in interface ParserInterface

Returns:

The object housing this parser

setContext

public void setContext(Object context)

Set the context in which the parser runs. This method is optionally called by any object that wants to make itself visible to the parser.

Specified by:

setContext in interface ParserInterface

Parameters:

context - The context object

setParser

public void setParser(ParserInterface parser)

Set the chained parser (future implementation).

Specified by:

setParser in interface ParserInterface

Parameters:

parser - The chained parser

getParser

public ParserInterface getParser()

Return the chained parser (future implementation).

Specified by:

getParser in interface ParserInterface

Returns:

The chained parser

setParam

public void setParam(String param,
                     String value)

Set parser configuration value.

Specified by:

setParam in interface ParserInterface

Parameters:

param - The parameter name

value - The parameter value

getParam

public String getParam(String param)

Return configuration value.

Specified by:

getParam in interface ParserInterface

Parameters:

param - The name of the parameter to return

Returns:

The value associated with the parameter or null.

setConfiguration

public void setConfiguration(ParserConfig config)

Set the parser configuration. This method is called by instantiating classes to provide the parser with a configuration object.

Specified by:

setConfiguration in interface ParserInterface

Parameters:

config - The configuration object

setInputStream

public void setInputStream(InputStream is)

Set the parser input stream. This method sets the input stream object from which the parser will read it's data. If the configuration has an encryptionKey parameter set, then this method will make an instance of the EncryptedReader to decrypt the underlying input stream. If no encryptionKey is specified then an instance of java.io.BufferedReader is used to provide buffered access to the input stream. Also, if the characterSet configuration parameter is set the input stream is read/decoded according the character set specified by that parameter.

Specified by:

setInputStream in interface ParserInterface

Parameters:

is - The InputStream object (e.g. FileInputStream, SocketInputStream etc. ..)

setOutputStream

public void setOutputStream(OutputStream os)

Set the parser output stream. This method sets the output stream object to which the parser will write it's data. If the configuration has an encryptionKey parameter set, then this method will make an instance of the EncryptedWriter to encrypt data to the underlying output stream. If no encryptionKey is specified then an instance of java.io.BufferedWriter is used to provide buffered access to the output stream. Also, if the characterSet configuration parameter is set the output stream is written according the character set specified by that parameter.

Specified by:

setOutputStream in interface ParserInterface

Parameters:

os - The OutputStream object (e.g. FileOutputStream, SocketOutputStream etc. ..)

setInputStream

public void setInputStream(String is)

Use a string as input. This method creates an instance of the StringReader class to read data from a String rather than an input stream.

Specified by:

setInputStream in interface ParserInterface

Parameters:

is - String to read data from

setInputStream

public void setInputStream(Reader is)

Use Reader object for input. This method creates an instance of the BufferedReader class providing the is reader object as input. Use this method to pass an already created instance of any Reader class (e.g. FileReader, StringReader ...). If the encryptionKey parameter is set an instance of the EncryptedReader is used on top of the provided Reader to decrypt the input stream.

Specified by:

setInputStream in interface ParserInterface

Parameters:

is - Reader object

setOutputStream

public void setOutputStream(Writer os)

Use Writer object for output. This method creates an instance of the BufferedWriter class providing the os writer object as input. Use this method to pass an already created instance of any Writer class (e.g. FileReader, StringReader ...). If the encryptionKey parameter is set an instance of the EncryptedWriter is used on top of the provided Writer to encrypt the output stream.

Specified by:

setOutputStream in interface ParserInterface

Parameters:

os - Writer object

getReader

public BufferedReader getReader()

Return current reader object.

Specified by:

getReader in interface ParserInterface

Returns:

The reader object being used for input

getWriter

public BufferedWriter getWriter()

Return current writer object.

Specified by:

getWriter in interface ParserInterface

Returns:

The writer object being used for output

getInputStream

public InputStream getInputStream()

Return current input-stream object. This may be null if the parser was initialized with a Reader object.

Returns:

The inputstream object being used for input

getOutputStream

public OutputStream getOutputStream()

Return current output-stream object. This may be null if the parser was initialized with a Writer object.

Returns:

The outputstream object being used for output

initParser

public void initParser()
                throws Exception

Perform initialization of parser.

Specified by:

initParser in interface ParserInterface

Throws:

Exception - if an error occurs.

closeParser

public void closeParser()
                 throws Exception

Close parser and deallocate resources. This method closes the input and output streams.

Specified by:

closeParser in interface ParserInterface

Throws:

Exception - if an error occurs.

getClassInstance

public static Object getClassInstance(String className)
                               throws Exception

Create a parser instance. This method dynamically creates a new instance of a parser class based on the class name provided.

Parameters:

className - The complete Java class name

Returns:

The parser class instance

Throws:

Exception -

if the className could not be found.

if the constructor is not visible to the sender.

if the instance could not be created.

logmsg

public void logmsg(String msg)

Writes a message to the log. If the parser has a context then the context is examined for a known class (like connector, switchboard) and then calls the context's logmsg method. If no context exists or the context object type is unknown nothing is done.

Parameters:

msg - The log message

debug

public void debug(String msg)

Writes a message to the log if debug mode is set.

Parameters:

msg - The log message

debugMode

public boolean debugMode()

Returns current status of the debugMode flag. May be called by different threads.

Returns:

true if debug mode is enabled, false otherwise.

getDebug

public boolean getDebug()

Returns current status of the debugMode flag. May be called by different threads.

Specified by:

getDebug in interface ParserInterface

Returns:

True if debug mode is enabled, false otherwise.

setDebug

public void setDebug(boolean debug)

Sets the status of the debugMode flag. May be called by different threads.

Specified by:

setDebug in interface ParserInterface

Parameters:

debug - True if debug mode is enabled, false otherwise.

registerScriptBeans

public void registerScriptBeans(ScriptEngine se)
                         throws Exception

Register objects in the script engine. This method may be called by a hosting object to let the parser register objects in the script engine. This allows the user to access parser specific objects using predefined names in the scripting environment. The default implementation is to declare parser as a reference to the parser class instance.

Specified by:

registerScriptBeans in interface ParserInterface

Parameters:

se - The script engine

Throws:

Exception

flush

public void flush()
           throws Exception

This method is called by some hosting components to flush any in-memory data to the current output stream.

Specified by:

flush in interface ParserInterface

Throws:

Exception

isDeltaSupported

public boolean isDeltaSupported()

Returns true if this connector is able to perform delta updates

Specified by:

isDeltaSupported in interface ParserInterface

Returns:

false

querySchema

public Object querySchema(Object source)
                   throws Exception

Discover the schema for the Parser. For example, a XML Parser could return a representation of the XML Schema or the DTD referenced in a XML file.

Specified by:

querySchema in interface ParserInterface

Parameters:

source - The object on which to discover schema

Returns:

A Vector of com.ibm.di.entry.Entry objects describing each entity

Throws:

Exception - If an I/O error occurs