com.jcorporate.expresso.core.dataobjects
Class DefaultDataField

java.lang.Object
  com.jcorporate.expresso.core.dataobjects.DefaultDataField

All Implemented Interfaces:

DataField, Serializable

public class DefaultDataField

extends Object

implements DataField, Serializable

Default implementation of the DataField interface. This class provides some basic conversion capabilities between different Java types as well as provides all use change logging capabilities.

Since:

Expresso 5.0

Author:

Michael Rimov

See Also:

Serialized Form

Field Summary

static String	ATTRIBUTE_ERROR Attribute String for if there's an error with the field.
static String	ATTRIBUTE_ERROR_MESSAGE Attribute String for what message to display if there's an error with thie field.
protected Map	attributes A generic map of attribute keys to attribute values
protected Object	currentValue The Current Value
protected boolean	isChanged Flag to signify if the field is changed
protected boolean	isValueSet Flag to signify if the field value has been set - the retrieved value may be null
protected DataFieldMetaData	myMetaData A link to my metadata.
protected Object	originalValue The original value, used in comparison tests for 'isChanged' calculation; set by first retrieve(); reset after add() or update()
protected DataObject	owner A link to the DataObject that contains me.

Constructor Summary

protected

DefaultDataField(DataFieldMetaData metaData, DataObject parentObject) Creates a new DefaultDataField object.

Method Summary

BigDecimal	asBigDecimal() Retrieve the wrapped object as a BigDecimal object or zero if we're unable to convert it.
Boolean	asBoolean() Retrieve the boolean object value.
Date	asDate() Retrieve the wrapped object as a Date object or possibly null if we can't convert it or the object is null.
Double	asDouble() Retrieve the wrapped object as a Double object or zero if we can't convert i
Integer	asInteger() Retrieves the wrapped object as an Integer or zero if it's an invalid format.
InputStream	asStream() Retrieve the field as a InputStream.
String	asString() Retrieves the wrapped object as a String
void	cacheIsChangedComparison() reset 'original' value and isChanged flags; call when add(), retrieve() or update() has occurred, and currentValue of data fields should be considered 'original value' for purposes of determining 'isChanged'
void	checkValue() Make sure the value of the field is valid.
Map	getAllAttributes() Returns a Read Only Map of all attributes in name-value pairs.
Object	getAttribute(String attributeName) Retrieves any user defined attributes for this field.
protected String	getBooleanFieldValue(Boolean theFieldValue) Internal refactoring for getting what a boolean field should be set to.
DataFieldMetaData	getFieldMetaData() Returns a handle to the Field MetaData object.
static DefaultDataField	getInstance(DataFieldMetaData metaData, DataObject parentObject) create new object for this field
Object	getOriginalValue() Retrieve the last original value if the data has changed.
DataObject	getOwner() Returns a handle to the DataObject that is the container for this Data Field
protected org.apache.oro.text.regex.PatternMatcher	getPatternMatcher() Retrieve a thread local instance of the Perl5 pattern matcher.
Object	getSerializedForm() Returns the form in a way suitable for storage in a database or other data source.
protected SimpleDateFormat	getSimpleDateFormat(String pattern) Get a SimpleDateFormat object that is cached.
Object	getValue() retrieve value object for this field
boolean	isChanged() Used for change logging and updating only changed fields.
boolean	isNull() Returns true if the object is null.
boolean	isValueSet() Used for change logging.
void	release() set all internal data members to null;
void	removeAttribute(String attribute) Removes an attribute
void	resetChanged() Resets the isChanged and isValueSet flags and sets the original value field to null
void	setAttribute(String attributeName, Object value) Sets an attribute for this particular instance of the Data field
void	setFieldMetaData(DataFieldMetaData newMetadata) Sets the metadata object for this field.
void	setOwner(DataObject newOwner) Sets the owner of a given DataObject
void	setSerializedForm(Object o) Used for setting raw data from a JDBC connection.
void	setValue(Object newValue) Sets the wrapped object for the data field; also updates values for isValueSet and isChanged flags

Methods inherited from class java.lang.Object

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

Field Detail

ATTRIBUTE_ERROR

public static final String ATTRIBUTE_ERROR

Attribute String for if there's an error with the field.

See Also:

Constant Field Values

ATTRIBUTE_ERROR_MESSAGE

public static final String ATTRIBUTE_ERROR_MESSAGE

Attribute String for what message to display if there's an error with thie field.

See Also:

Constant Field Values

myMetaData

protected transient DataFieldMetaData myMetaData

A link to my metadata.

owner

protected transient DataObject owner

A link to the DataObject that contains me.

attributes

protected Map attributes

A generic map of attribute keys to attribute values

currentValue

protected Object currentValue

The Current Value

originalValue

protected Object originalValue

The original value, used in comparison tests for 'isChanged' calculation; set by first retrieve(); reset after add() or update()

isChanged

protected boolean isChanged

Flag to signify if the field is changed

isValueSet

protected boolean isValueSet

Flag to signify if the field value has been set - the retrieved value may be null

Constructor Detail

DefaultDataField

protected DefaultDataField(DataFieldMetaData metaData,
                           DataObject parentObject)

Creates a new DefaultDataField object.

Parameters:

metaData -

parentObject -

Method Detail

getInstance

public static DefaultDataField getInstance(DataFieldMetaData metaData,
                                           DataObject parentObject)

create new object for this field

Parameters:

metaData -

parentObject -

Returns:

new instance of this field

release

public void release()

set all internal data members to null;

setSerializedForm

public void setSerializedForm(Object o)

Used for setting raw data from a JDBC connection. Allows for special processing such as decryption.

Parameters:

o - the object to set.

getSerializedForm

public Object getSerializedForm()
                         throws DataException

Returns the form in a way suitable for storage in a database or other data source.

Returns:

java.lang.Object

Throws:

DataException - upon error

getValue

public Object getValue()

retrieve value object for this field

Specified by:

getValue in interface DataField

Returns:

Object which contains value

asString

public String asString()

Retrieves the wrapped object as a String

Specified by:

asString in interface DataField

Returns:

a String value representing the object as a string

asStream

public InputStream asStream()

Retrieve the field as a InputStream. If the object's native type is an input stream, it returns that. If it is a serializable object, it returns a ByteArrayInputStream that was created using a ByteArrayOutputStream as well as a ObjectOutputStream.

Specified by:

asStream in interface DataField

Returns:

java.io.InputSTream or null if there was an IO Exception getting the value, the value was null, of if the native object is not serializable

asInteger

public Integer asInteger()

Retrieves the wrapped object as an Integer or zero if it's an invalid format.

Specified by:

asInteger in interface DataField

Returns:

a java.lang.Integer object, or null if the object is null.

asDate

public Date asDate()

Retrieve the wrapped object as a Date object or possibly null if we can't convert it or the object is null.

Specified by:

asDate in interface DataField

Returns:

a properly instantiated Date Object if we're able to convert it.

getSimpleDateFormat

protected SimpleDateFormat getSimpleDateFormat(String pattern)

Get a SimpleDateFormat object that is cached. Make sure you have dateConvertFormatMap already locked before calling this function or you'll have a race condition.

Parameters:

pattern - the format pattern to look up

Returns:

an instantiated SimpleDateFormat object. SimpleDateFormat is NOT threadsafe, so make sure you do your parsing while still in the synchronized block. Perhaps in the future a keyed Object pool will be better.

asBigDecimal

public BigDecimal asBigDecimal()

Retrieve the wrapped object as a BigDecimal object or zero if we're unable to convert it.

Specified by:

asBigDecimal in interface DataField

Returns:

a properly instantiated BigDecimal Object if we're able to convert it.

asDouble

public Double asDouble()

Retrieve the wrapped object as a Double object or zero if we can't convert i

Specified by:

asDouble in interface DataField

Returns:

a properly instantiated Double Object if we're able to convert it.

asBoolean

public Boolean asBoolean()

Retrieve the boolean object value.

Specified by:

asBoolean in interface DataField

Returns:

Boolean object. Null if the object's value is null

getOriginalValue

public Object getOriginalValue()

Retrieve the last original value if the data has changed. Will return null if isChanged() is false

Specified by:

getOriginalValue in interface DataField

Returns:

the original object or null

isChanged

public boolean isChanged()

Used for change logging and updating only changed fields. change is true IF the field has been set once (after object is born or reset), and subsequently the value is changed in the field.

Specified by:

isChanged in interface DataField

Returns:

true if the field has changed since the last reset (i.e. since object was constructed or reset)

isValueSet

public boolean isValueSet()

Used for change logging.

Specified by:

isValueSet in interface DataField

Returns:

true if the field has had the value set since the last reset

checkValue

public void checkValue()
                throws DataException

Make sure the value of the field is valid. Checks mask and for null.

Specified by:

checkValue in interface DataField

Throws:

DataException - if the field value is not valid

resetChanged

public void resetChanged()

Resets the isChanged and isValueSet flags and sets the original value field to null

Specified by:

resetChanged in interface DataField

setValue

public void setValue(Object newValue)

Sets the wrapped object for the data field; also updates values for isValueSet and isChanged flags

Specified by:

setValue in interface DataField

Parameters:

newValue - a new Object to set the value to

isNull

public boolean isNull()

Returns true if the object is null.

Specified by:

isNull in interface DataField

Returns:

true if the object is null

setAttribute

public void setAttribute(String attributeName,
                         Object value)

Sets an attribute for this particular instance of the Data field

Specified by:

setAttribute in interface DataField

Parameters:

attributeName - the name of the attribute to set

value - the value to set it to

removeAttribute

public void removeAttribute(String attribute)

Removes an attribute

Parameters:

attribute - The attribute key to remove

getAttribute

public Object getAttribute(String attributeName)

Retrieves any user defined attributes for this field.

Specified by:

getAttribute in interface DataField

Parameters:

attributeName - the name of the attribute to retrieve

Returns:

an object or null if the attribute doesn't exist

getAllAttributes

public Map getAllAttributes()

Returns a Read Only Map of all attributes in name-value pairs. If there are no attributes then getAllAttributes will return a null map.

Specified by:

getAllAttributes in interface DataField

Returns:

java.util.map

getOwner

public DataObject getOwner()

Returns a handle to the DataObject that is the container for this Data Field

Specified by:

getOwner in interface DataField

Returns:

DataObject the containing data object.

setOwner

public void setOwner(DataObject newOwner)

Sets the owner of a given DataObject

Specified by:

setOwner in interface DataField

Parameters:

newOwner - The new parent object.

getFieldMetaData

public DataFieldMetaData getFieldMetaData()

Returns a handle to the Field MetaData object.

Specified by:

getFieldMetaData in interface DataField

Returns:

DataFieldMetaData

setFieldMetaData

public void setFieldMetaData(DataFieldMetaData newMetadata)

Sets the metadata object for this field.

Specified by:

setFieldMetaData in interface DataField

Parameters:

newMetadata - the new Field Meta data object... for example DBField

getBooleanFieldValue

protected String getBooleanFieldValue(Boolean theFieldValue)

Internal refactoring for getting what a boolean field should be set to.

Parameters:

theFieldValue - The target value

Returns:

the string value

Throws:

IllegalArgumentException - If we can't get the data context

getPatternMatcher

protected org.apache.oro.text.regex.PatternMatcher getPatternMatcher()

Retrieve a thread local instance of the Perl5 pattern matcher. Allows for optimization of # of instances of pattern matcher vs synchronization.

Returns:

PatternMatcher

cacheIsChangedComparison

public void cacheIsChangedComparison()

reset 'original' value and isChanged flags; call when add(), retrieve() or update() has occurred, and currentValue of data fields should be considered 'original value' for purposes of determining 'isChanged'

Specified by:

cacheIsChangedComparison in interface DataField