edu.harvard.hul.ois.jhove
Class HandlerBase

java.lang.Object
  edu.harvard.hul.ois.jhove.HandlerBase

All Implemented Interfaces:

OutputHandler

Direct Known Subclasses:

TextHandler, ViewHandler, XmlHandler

public abstract class HandlerBase
extends java.lang.Object
implements OutputHandler

Abstract base class for Jhove output handlers. Output handlers should normally subclass HandlerBase.

Nested Class Summary

static class

HandlerBase.SynchronizedDateFormat A DateFormat class to address an issue of thread safety.

Field Summary

protected App	_app The application object
protected JhoveBase	_base The Jhove engine
protected java.util.Date	_date Handler last modification date
protected java.util.List<java.lang.String>	_defaultParams List of default parameters.
protected java.lang.String	_encoding Character encoding for writer
protected java.lang.String	_init Initialization value.
protected JhoveBase	_je JHOVE engine.
protected int	_level Indentation level
protected java.util.logging.Logger	_logger Logger for a handler class.
protected java.lang.String	_name Handler name
protected java.lang.String	_note Handler note
protected java.lang.String	_param Handler-specific parameter.
protected java.lang.String	_release Handler release description.
protected java.lang.String	_rights Copyright notice
protected java.util.List<Document>	_specification Handler specification document list
protected Agent	_vendor Handler vendor
protected java.io.PrintWriter	_writer Writer for doing output
static HandlerBase.SynchronizedDateFormat	date A DateFormat for representing a Date in yyyy-MM-dd (e.g., 2003-07-31) format.
static HandlerBase.SynchronizedDateFormat	dateTime A DateFormat for representing a Date in yyyy-MM-dd HH:mm:ss z (e.g., 2003-07-31 15:31:12 EDT) format.
static HandlerBase.SynchronizedDateFormat	iso8601 A DateFormat for representing a Date in ISO 8601 (e.g., 2003-07-31T15:31:12-0400) format.

Constructor Summary

protected

HandlerBase(java.lang.String name, java.lang.String release, int[] date, java.lang.String note, java.lang.String rights) Constructors of all subclasses of HandlerBase should call this as a super constructor.

Method Summary

void	analyze(RepInfo info) Callback allowing post-parse, pre-show analysis of object representation information.
void	applyDefaultParams() Applies the default parameters.
void	close() Close the writer after all output has been done.
protected static java.lang.String	doctype(java.lang.String root, java.lang.String uri) Return the XML DOCTYPE instruction.
protected static java.lang.String	doctype(java.lang.String root, java.lang.String name, java.lang.String uri) Return the XML DOCTYPE instruction.
protected static java.lang.String	doubleArray(double[] darray) Return String representation of an array of double.
protected static java.lang.String	element(java.lang.String tag) Returns, as a String, an empty XML.
protected static java.lang.String	element(java.lang.String tag, java.lang.String content) Returns, as a String, an XML element with a given tag and content
protected static java.lang.String	element(java.lang.String tag, java.lang.String[][] attrs) Returns, as a String, an XML element with a given tag and attributes
protected static java.lang.String	element(java.lang.String tag, java.lang.String[][] attrs, java.lang.String content) Returns, as a String, an XML element with a given tag, content and attributes
protected static java.lang.String	elementEnd(java.lang.String tag) Returns, as a String, the closing tag of an element.
protected static java.lang.String	elementStart(java.lang.String tag) Returns, as a String, the opening tag of an element.
protected static java.lang.String	elementStart(java.lang.String tag, java.lang.String[][] attrs) Returns, as a String, the opening tag of an element with specified attributes.
void	endDirectory() Callback indicating a directory is finished being processed.
java.util.Date	getDate() Return the last modification date of this OutputHandler, as a Java Date object
java.lang.String	getEncoding() Returns this handler's encoding.
protected static java.lang.String	getIndent(int level) Returns a String containing a number of spaces equal to the current indent level.
java.lang.String	getName() Return the OutputHandler name
java.lang.String	getNote() Return the OutputHandler note
java.lang.String	getRelease() Return the release identifier
java.lang.String	getRights() Return the copyright information string
java.util.List<Document>	getSpecification() Returns a list of Document objects (one for each specification document).
Agent	getVendor() Return the vendor information
void	init(java.lang.String init) Per-instantiation initialization.
protected static java.lang.String	integerArray(int[] iarray) Return String representation of an integer array.
protected static java.lang.String	integerArray(int[] iarray, char separator) Return String representation of an integer array with specified separator.
protected static java.lang.String	longArray(long[] larray) Return String representation of an array of long with space separator.
boolean	okToProcess(java.lang.String filepath) Callback to give the handler the opportunity to decide whether or not to process a file.
void	param(java.lang.String param) Per-action initialization.
protected static java.lang.String	rationalArray(Rational[] rarray) Return String representation of an array of Rational, each evaluated as a double, with space separator.
protected static java.lang.String	rationalArray10(Rational[] rarray) Return String representation of an array of Rational, each as two integers, with space separator.
void	reset() Reset the handler.
void	resetParams() Reset parameter settings.
void	setApp(App app) Pass the associated App object to this Module.
void	setBase(JhoveBase je) Assigns the JHOVE engine object to provide services to this handler
void	setDefaultParams(java.util.List<java.lang.String> params) Set a a List of default parameters for the module.
void	setEncoding(java.lang.String encoding) Assigns the encoding to be used by this OutputHandler
void	setWriter(java.io.PrintWriter writer) Assigns a PrintWriter to do output for this OutputHandler
abstract void	show() Outputs minimal information about the application
abstract void	show(App app) Outputs detailed information about the application, including configuration, available modules and handlers, etc.
abstract void	show(Module module) Outputs information about a Module
abstract void	show(OutputHandler handler) Outputs information about the OutputHandler specified in the parameter
abstract void	show(RepInfo info) Outputs the information contained in a RepInfo object
abstract void	showFooter() Do the final output.
abstract void	showHeader() Do the initial output.
void	startDirectory(java.lang.String directory) Callback indicating a new directory is being processed.
protected java.lang.String	toDateTime(java.util.Date date)
protected static java.lang.String	xmlDecl() Return a canonical XML declaration with default encoding.
protected static java.lang.String	xmlDecl(java.lang.String encoding) Return a canonical XML declaration with specified encoding.

Methods inherited from class java.lang.Object

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

Field Detail

date

public static HandlerBase.SynchronizedDateFormat date

A DateFormat for representing a Date in yyyy-MM-dd (e.g., 2003-07-31) format.

dateTime

public static HandlerBase.SynchronizedDateFormat dateTime

A DateFormat for representing a Date in yyyy-MM-dd HH:mm:ss z (e.g., 2003-07-31 15:31:12 EDT) format.

iso8601

public static HandlerBase.SynchronizedDateFormat iso8601

A DateFormat for representing a Date in ISO 8601 (e.g., 2003-07-31T15:31:12-0400) format. We subclass SimpleDateFormat to make it thread-safe.

_app

protected App _app

The application object

_base

protected JhoveBase _base

The Jhove engine

_date

protected java.util.Date _date

Handler last modification date

_encoding

protected java.lang.String _encoding

Character encoding for writer

_init

protected java.lang.String _init

Initialization value.

_defaultParams

protected java.util.List<java.lang.String> _defaultParams

List of default parameters.

_je

protected JhoveBase _je

JHOVE engine.

_level

protected int _level

Indentation level

_name

protected java.lang.String _name

Handler name

_note

protected java.lang.String _note

Handler note

_release

protected java.lang.String _release

Handler release description.

_param

protected java.lang.String _param

Handler-specific parameter.

_rights

protected java.lang.String _rights

Copyright notice

_specification

protected java.util.List<Document> _specification

Handler specification document list

_vendor

protected Agent _vendor

Handler vendor

_writer

protected java.io.PrintWriter _writer

Writer for doing output

_logger

protected java.util.logging.Logger _logger

Logger for a handler class.

Constructor Detail

HandlerBase

protected HandlerBase(java.lang.String name,
                      java.lang.String release,
                      int[] date,
                      java.lang.String note,
                      java.lang.String rights)

Constructors of all subclasses of HandlerBase should call this as a super constructor.

Parameters:

name - Name of the handler

release - Release identifier

date - Last modification date of the handler code, in the form of an array of three numbers. date[0] is the year, date[1] the month, and date[2] the day.

note - Additional information about the handler (may be null)

rights - Copyright notice for the handler

Method Detail

reset

public void reset()

Reset the handler. This needs to be called before each invocation.

Specified by:

reset in interface OutputHandler

setDefaultParams

public void setDefaultParams(java.util.List<java.lang.String> params)

Set a a List of default parameters for the module.

Specified by:

setDefaultParams in interface OutputHandler

Parameters:

params - A List whose elements are Strings. May be empty.

applyDefaultParams

public void applyDefaultParams()
                        throws java.lang.Exception

Applies the default parameters. Calling this clears any prior parameters.

Specified by:

applyDefaultParams in interface OutputHandler

Throws:

java.lang.Exception

resetParams

public void resetParams()
                 throws java.lang.Exception

Reset parameter settings. Returns to a default state without any parameters. The default method clears the saved parameter.

Specified by:

resetParams in interface OutputHandler

Throws:

java.lang.Exception

init

public void init(java.lang.String init)
          throws java.lang.Exception

Per-instantiation initialization. The default method does nothing.

Specified by:

init in interface OutputHandler

Parameters:

init - Initialization parameter. This is typically obtained from the configuration file.

Throws:

java.lang.Exception

param

public void param(java.lang.String param)
           throws java.lang.Exception

Per-action initialization. The default method does nothing.

Specified by:

param in interface OutputHandler

Parameters:

param - Initialization parameter.

Throws:

java.lang.Exception

getDate

public final java.util.Date getDate()

Return the last modification date of this OutputHandler, as a Java Date object

Specified by:

getDate in interface OutputHandler

getName

public final java.lang.String getName()

Return the OutputHandler name

Specified by:

getName in interface OutputHandler

getNote

public final java.lang.String getNote()

Return the OutputHandler note

Specified by:

getNote in interface OutputHandler

getRelease

public final java.lang.String getRelease()

Return the release identifier

Specified by:

getRelease in interface OutputHandler

getRights

public final java.lang.String getRights()

Return the copyright information string

Specified by:

getRights in interface OutputHandler

getSpecification

public final java.util.List<Document> getSpecification()

Returns a list of Document objects (one for each specification document). The specification list is generated by the OutputHandler, and specifications cannot be added by callers.

Specified by:

getSpecification in interface OutputHandler

See Also:

Document

getVendor

public final Agent getVendor()

Return the vendor information

Specified by:

getVendor in interface OutputHandler

getEncoding

public java.lang.String getEncoding()

Returns this handler's encoding.

Specified by:

getEncoding in interface OutputHandler

setApp

public final void setApp(App app)

Pass the associated App object to this Module. The App makes various services available.

Specified by:

setApp in interface OutputHandler

setBase

public final void setBase(JhoveBase je)

Assigns the JHOVE engine object to provide services to this handler

Specified by:

setBase in interface OutputHandler

setEncoding

public void setEncoding(java.lang.String encoding)

Assigns the encoding to be used by this OutputHandler

Specified by:

setEncoding in interface OutputHandler

setWriter

public final void setWriter(java.io.PrintWriter writer)

Assigns a PrintWriter to do output for this OutputHandler

Specified by:

setWriter in interface OutputHandler

analyze

public void analyze(RepInfo info)

Callback allowing post-parse, pre-show analysis of object representation information.

Specified by:

analyze in interface OutputHandler

Parameters:

info - Object representation information

endDirectory

public void endDirectory()

Callback indicating a directory is finished being processed.

Specified by:

endDirectory in interface OutputHandler

okToProcess

public boolean okToProcess(java.lang.String filepath)

Callback to give the handler the opportunity to decide whether or not to process a file. Most handlers will always return true.

Specified by:

okToProcess in interface OutputHandler

Parameters:

filepath - File pathname

show

public abstract void show(Module module)

Outputs information about a Module

Specified by:

show in interface OutputHandler

show

public abstract void show(RepInfo info)

Outputs the information contained in a RepInfo object

Specified by:

show in interface OutputHandler

show

public abstract void show(OutputHandler handler)

Outputs information about the OutputHandler specified in the parameter

Specified by:

show in interface OutputHandler

show

public abstract void show()

Outputs minimal information about the application

Specified by:

show in interface OutputHandler

show

public abstract void show(App app)

Outputs detailed information about the application, including configuration, available modules and handlers, etc.

Specified by:

show in interface OutputHandler

showHeader

public abstract void showHeader()

Do the initial output. This should be in a suitable format for including multiple files between the header and the footer.

Specified by:

showHeader in interface OutputHandler

showFooter

public abstract void showFooter()

Do the final output. This should be in a suitable format for including multiple files between the header and the footer.

Specified by:

showFooter in interface OutputHandler

close

public void close()

Close the writer after all output has been done.

Specified by:

close in interface OutputHandler

startDirectory

public void startDirectory(java.lang.String directory)

Callback indicating a new directory is being processed.

Specified by:

startDirectory in interface OutputHandler

Parameters:

directory - Directory path

doctype

protected static java.lang.String doctype(java.lang.String root,
                                          java.lang.String uri)

Return the XML DOCTYPE instruction.

Parameters:

root - Root element of the DTD

uri - URI of the DTD

doctype

protected static java.lang.String doctype(java.lang.String root,
                                          java.lang.String name,
                                          java.lang.String uri)

Return the XML DOCTYPE instruction.

Parameters:

root - Root element of the DTD

name - Public name of the DTD

uri - URI of the DTD

element

protected static java.lang.String element(java.lang.String tag)

Returns, as a String, an empty XML.

Parameters:

tag - XML tag

element

protected static java.lang.String element(java.lang.String tag,
                                          java.lang.String content)

Returns, as a String, an XML element with a given tag and content

Parameters:

tag - An XML tag

content - Content string. Characters requiring conversion to entitites will be converted.

element

protected static java.lang.String element(java.lang.String tag,
                                          java.lang.String[][] attrs)

Returns, as a String, an XML element with a given tag and attributes

Parameters:

tag - An XML tag

attrs - An array of String[2] elements, where for each element, attrs[i][0] is the attribute key and attrs[i][1] is the attribute value. Null values are skipped.

element

protected static java.lang.String element(java.lang.String tag,
                                          java.lang.String[][] attrs,
                                          java.lang.String content)

Returns, as a String, an XML element with a given tag, content and attributes

Parameters:

tag - An XML tag

content - Content string. Characters requiring conversion to entitites will be converted.

attrs - An array of String[2] elements, where for each element, attrs[i][0] is the attribute key and attrs[i][1] is the attribute value. Null values are skipped.

elementEnd

protected static java.lang.String elementEnd(java.lang.String tag)

Returns, as a String, the closing tag of an element. No checking is done that opening and closing tags match.

Parameters:

tag - An XML tag

elementStart

protected static java.lang.String elementStart(java.lang.String tag)

Returns, as a String, the opening tag of an element.

Parameters:

tag - An XML tag

elementStart

protected static java.lang.String elementStart(java.lang.String tag,
                                               java.lang.String[][] attrs)

Returns, as a String, the opening tag of an element with specified attributes.

Parameters:

tag - An XML tag

attrs - An array of String[2] elements, where for each element, attrs[i][0] is the attribute key and attrs[i][1] is the attribute value.

xmlDecl

protected static java.lang.String xmlDecl()

Return a canonical XML declaration with default encoding.

xmlDecl

protected static java.lang.String xmlDecl(java.lang.String encoding)

Return a canonical XML declaration with specified encoding.

getIndent

protected static java.lang.String getIndent(int level)

Returns a String containing a number of spaces equal to the current indent level.

integerArray

protected static java.lang.String integerArray(int[] iarray)

Return String representation of an integer array.

integerArray

protected static java.lang.String integerArray(int[] iarray,
                                               char separator)

Return String representation of an integer array with specified separator.

longArray

protected static java.lang.String longArray(long[] larray)

Return String representation of an array of long with space separator.

rationalArray

protected static java.lang.String rationalArray(Rational[] rarray)

Return String representation of an array of Rational, each evaluated as a double, with space separator.

rationalArray10

protected static java.lang.String rationalArray10(Rational[] rarray)

Return String representation of an array of Rational, each as two integers, with space separator.

doubleArray

protected static java.lang.String doubleArray(double[] darray)

Return String representation of an array of double.

toDateTime

protected java.lang.String toDateTime(java.util.Date date)