com.jcorporate.expresso.core.dataobjects
Interface DataObjectMetaData

All Superinterfaces:

Serializable

All Known Subinterfaces:

JDBCObjectMetaData

All Known Implementing Classes:

DBObjectDef, JoinedDataObjectMetaData

public interface DataObjectMetaData

extends Serializable

This interface contains the "definition" of the DBObject, while the DBObject itself contains only the data itself. One DBObjectDef object is stored in a static HashMap in the DBObject class, and is looked up and referenced for all definitions of the structure of the given object.

since this class is not threadsafe for adding information, it is imperitive that all information addition, typically done when the first instance of a DBObject is instantiated, is done in a synchronized context.

Author:

Michael Rimov

Method Summary

boolean	checkZeroUpdate() Retrieves whether or not checkZeroUpdate is enabled for this data object
void	disableLogging() Disable change logging of all objects of this type
void	enableLogging() Enable logging of changes to this object.
Set	getAllAttributes(String fieldName) Retrieve all the attributes so you can iterate through them.
HashMap	getAllFieldsMap() Return the "allFields" Hashtable, which contains all of the DBField objects that make up this DB object.
HashMap	getAllKeysMap() Return the "allKeys" hash, containing the DBField objects that make up the primary key for this db object.
Object	getAttribute(String fieldName, String attribName) Gets an Object attribute from the field's metatdata
int	getCacheSize() Get the current Cache size of this object.
String	getCharset() return the current object's character set
String	getDefaultValue(String fieldName) Retreive the default value of a particular field for when it is first instantiated
String	getDescription() Return a description of this database object.
String	getDescription(Locale l) Retrieve the table description in a localized way.
String	getDescription(Locale l, String fieldName) Retrieve an localized description as per the locale defined for the 'client'
String	getDescription(String fieldName) Return the long description of a field, if available
String	getDetailFieldsForeign(String detailName) Retrieve the foreign key fields
String	getDetailFieldsLocal(String detailName) Retrieve the local key fields.
Set	getDetailSet() Retrieve a list of all the detail objects
ArrayList	getFieldListArray() Get a list of all of the fields in this object This is threadsafe in that it makes a new copy of the fieldNamesInOrder ArrayList
DataFieldMetaData	getFieldMetadata(String fieldName) Get the DBField object specified by the fieldname
String[]	getFields() This convenience method iterates through all the fields belonging to this DBObject returns an array of field names ( String ).
ArrayList	getKeyFieldListArray() Get a list of all of the names of the key fields in this object
String	getLength(String fieldName) Return the length of a field
int	getLengthInt(String fieldName) Return the length of a field as an integer
String	getLookupField(String fieldName) When you get a lookup object, to perform a complete mapping between the two, you need to know what field name in the remote object maps to this field.
String	getLookupObject(String fieldName) Get a field's lookup object - this is the name of another database object that can be used to look up valid values for this object.
String	getName() Get the name of this object
int	getPrecision(String fieldName) Retrieve the precision of a particular field
String	getSchema() Retrieve the schema object's class name associated with this data object
String	getType(String fieldName) Return the type of a field - this method returns the internal Expresso type
boolean	hasField(String fieldName) This method will return a boolean true if the field is defined in the DBOBject, false otherwise.
boolean	isAllowsNull(String fieldName) Returns whether the field allows null values or not.
boolean	isField(String fieldName) Check if a certain name is a field (of any kind) in this DBOBject
String	isFieldIgnoreCase(String fieldName) Check if a certain name is a field (of any kind) in this DBOBject since SQL is case insensitive, ignore case of field name for match, this method takes longer, so use isField if the field name is known precisely
boolean	isLoggingEnabled() Retrieves whether or not change logging is enabled for a particular data object
boolean	isMultiValued(String fieldName) Method called to determine if a particular field is multi-valued, that is does it have a set of specific values and descriptions
boolean	isReadOnly(String fieldName) Is a given field readOnly - these fields are not offered for entry when a form is produced by the generic database maintenance servlet
boolean	isSecret(String fieldName) Is a given field 'secret' - these fields are not shown when a list is produced by the generic database maintenance servlet (DBMaint).
boolean	isVirtual(String fieldName) Is a given field virtual?
void	removeAttribute(String fieldName, String attribName) Removes an attribute from the field.
void	setAttribute(String fieldName, String attribName, Object attribValue)
void	setCacheSize(int newValue) Sets the cache size for this DBObject
void	setCheckZeroUpdate(boolean newFlag) Turn on or off the facility to verify that when an update is made that at least one record got updated.

Method Detail

getDefaultValue

public String getDefaultValue(String fieldName)

Retreive the default value of a particular field for when it is first instantiated

Parameters:

fieldName - the name of the field to retrieve

Returns:

java.lang.String

getDetailSet

public Set getDetailSet()

Retrieve a list of all the detail objects

Returns:

java.util.Set

getDetailFieldsLocal

public String getDetailFieldsLocal(String detailName)

Retrieve the local key fields.

Parameters:

detailName - the name of the detail dbobject

Returns:

java.lang.String

getDetailFieldsForeign

public String getDetailFieldsForeign(String detailName)

Retrieve the foreign key fields

Parameters:

detailName - the name of the detail dbobject

Returns:

java.lang.String

isAllowsNull

public boolean isAllowsNull(String fieldName)
                     throws DBException

Returns whether the field allows null values or not.

Parameters:

fieldName - name of the field

Returns:

true if the field allows null

Throws:

DBException

removeAttribute

public void removeAttribute(String fieldName,
                            String attribName)

Removes an attribute from the field.

Parameters:

fieldName - the name of the field to remove the attribute

attribName - the attribute name to remove

setAttribute

public void setAttribute(String fieldName,
                         String attribName,
                         Object attribValue)
                  throws DBException

Parameters:

fieldName - the name of the field to set the attribute for

attribName - the name of the attribute to set

attribValue - the attribute to set

Throws:

DBException

getAttribute

public Object getAttribute(String fieldName,
                           String attribName)
                    throws DBException

Gets an Object attribute from the field's metatdata

Parameters:

fieldName - the name of the field for the attribute

attribName - the name of the attribute

Returns:

java.lang.Object

Throws:

DBException

getAllAttributes

public Set getAllAttributes(String fieldName)

Retrieve all the attributes so you can iterate through them.

Parameters:

fieldName - the name of the field to get all the attributes

Returns:

java.util.Set of all attributes.

disableLogging

public void disableLogging()

Disable change logging of all objects of this type

enableLogging

public void enableLogging()

Enable logging of changes to this object. Change logging writes an entry to the ChangeLog object every time an add, update, or delete is made to this object. It is used to track important tables, such as user information, account information, etc.

isLoggingEnabled

public boolean isLoggingEnabled()

Retrieves whether or not change logging is enabled for a particular data object

Returns:

boolean true if logging is enabled.

isFieldIgnoreCase

public String isFieldIgnoreCase(String fieldName)

Check if a certain name is a field (of any kind) in this DBOBject since SQL is case insensitive, ignore case of field name for match, this method takes longer, so use isField if the field name is known precisely

Parameters:

fieldName - the name of the field to check

Returns:

internal format for field name if matched, or null if no match

isField

public boolean isField(String fieldName)

Check if a certain name is a field (of any kind) in this DBOBject

Parameters:

fieldName - the name of the field to check

Returns:

true if the field name exists

getAllFieldsMap

public HashMap getAllFieldsMap()

Return the "allFields" Hashtable, which contains all of the DBField objects that make up this DB object.

Returns:

java.util.HashMap

getAllKeysMap

public HashMap getAllKeysMap()

Return the "allKeys" hash, containing the DBField objects that make up the primary key for this db object.

Returns:

java.util.HashMap

getCharset

public String getCharset()

return the current object's character set

Returns:

java.lang.String

getCacheSize

public int getCacheSize()

Get the current Cache size of this object. or -2 if it hasn't been defined yet.

Returns:

current cache size value.

setCacheSize

public void setCacheSize(int newValue)

Sets the cache size for this DBObject

Parameters:

newValue - the new value. Must be >= -2

Throws:

IllegalArgumentException - if newValue < -2

getDescription

public String getDescription()

Return a description of this database object. If no explicit description has been set, return the class name.

Returns:

A string describing this database object

getDescription

public String getDescription(String fieldName)
                      throws DBException

Return the long description of a field, if available

Parameters:

fieldName - The name of the field

Returns:

String: The long description of the field (user-readable)

Throws:

DBException - If there is no such field

getDescription

public String getDescription(Locale l,
                             String fieldName)

Retrieve an localized description as per the locale defined for the 'client'

Parameters:

l - the Locale to use. If null, will use the System default Locale

fieldName - the name of the field to retrieve the i18n'ized description for.

Returns:

the localized description of the field name

getFieldMetadata

public DataFieldMetaData getFieldMetadata(String fieldName)

Get the DBField object specified by the fieldname

Parameters:

fieldName - the name of the field to retrieve

Returns:

DBField object

getFieldListArray

public ArrayList getFieldListArray()

Get a list of all of the fields in this object This is threadsafe in that it makes a new copy of the fieldNamesInOrder ArrayList

Returns:

An array of all of the fieldNames in this object

getKeyFieldListArray

public ArrayList getKeyFieldListArray()

Get a list of all of the names of the key fields in this object

Returns:

An ArrayList of all of the names of the key fields

getLength

public String getLength(String fieldName)
                 throws DBException

Return the length of a field

Parameters:

fieldName - The name of the field

Returns:

String: The length of the field

Throws:

DBException - If there is no such field in this object

getLengthInt

public int getLengthInt(String fieldName)
                 throws DBException

Return the length of a field as an integer

Parameters:

fieldName - The name of the field

Returns:

integer: The length of the field

Throws:

DBException - If there is no such field in this object

getPrecision

public int getPrecision(String fieldName)
                 throws DBException

Retrieve the precision of a particular field

Parameters:

fieldName - The name of the field

Returns:

integer for demcimal precision of the field

Throws:

DBException

getLookupObject

public String getLookupObject(String fieldName)
                       throws DBException

Get a field's lookup object - this is the name of another database object that can be used to look up valid values for this object. The lookup object for a field is set in the db objects setupFields method, and is used by the DBMaint servlet to provide automatic lookup links for fields.

Parameters:

fieldName - Field name to check

Returns:

String specifying the className of the lookup object

Throws:

DBException - If the specified field does not exist.

getLookupField

public String getLookupField(String fieldName)

When you get a lookup object, to perform a complete mapping between the two, you need to know what field name in the remote object maps to this field.

Parameters:

fieldName - the name of the field to look up.

Returns:

java.lang.String or null if there is no lookup field

Throws:

IllegalArgumentException - if the field name does not exist

getName

public String getName()

Get the name of this object

Returns:

String The database object name, or the table name if none has been assigned

getType

public String getType(String fieldName)
               throws DBException

Return the type of a field - this method returns the internal Expresso type

Parameters:

fieldName - The name of the field

Returns:

String: The type of the field

Throws:

DBException - If there is no such field in this object

hasField

public boolean hasField(String fieldName)

This method will return a boolean true if the field is defined in the DBOBject, false otherwise. Creation date: (8/8/00 11:04:32 AM)

Parameters:

fieldName - java.lang.String

Returns:

boolean

isMultiValued

public boolean isMultiValued(String fieldName)
                      throws DBException

Method called to determine if a particular field is multi-valued, that is does it have a set of specific values and descriptions

Parameters:

fieldName - Name of the field

Returns:

boolean True if the field is multi-valued, false if not

Throws:

DBException - If there is no such field

isReadOnly

public boolean isReadOnly(String fieldName)
                   throws DBException

Is a given field readOnly - these fields are not offered for entry when a form is produced by the generic database maintenance servlet

Parameters:

fieldName - name of the field to check

Returns:

true of the field is "read only", false if it is not

Throws:

DBException - Ff there is no such field

isSecret

public boolean isSecret(String fieldName)
                 throws DBException

Is a given field 'secret' - these fields are not shown when a list is produced by the generic database maintenance servlet (DBMaint). This means that only users with update permission to the record can see the value of the specified field.

Parameters:

fieldName - The name of the field to check

Returns:

True if the field is 'secret', false if it is not

Throws:

DBException - If there is no such field.

isVirtual

public boolean isVirtual(String fieldName)
                  throws DBException

Is a given field virtual? A virtual field is not stored in the target table for this object - it may be computed, or stored in another table.

Parameters:

fieldName - The name of the field to check

Returns:

True of the field is virtual, false if it is not

Throws:

DBException - If there is no such field

setCheckZeroUpdate

public void setCheckZeroUpdate(boolean newFlag)

Turn on or off the facility to verify that when an update is made that at least one record got updated. If this flag is on, and no records get updated, the update() method throws an Exception. Note that for some databases, if the existing record is not changed (e.g. it was already identical to what was being updated) this counts "no update" (notably, mySQL does this).

Parameters:

newFlag - True to turn on checking, false to turn it off

checkZeroUpdate

public boolean checkZeroUpdate()

Retrieves whether or not checkZeroUpdate is enabled for this data object

Returns:

true if checkZeroUpdate() is enabled

getSchema

public String getSchema()

Retrieve the schema object's class name associated with this data object

Returns:

the className of the schema associated with this DBObject

getFields

public String[] getFields()

This convenience method iterates through all the fields belonging to this DBObject returns an array of field names ( String ).

Returns:

String array of all field names in this object.

See Also:

#getFieldList()

getDescription

public String getDescription(Locale l)

Retrieve the table description in a localized way. If l == null, the function uses the system locale to generate the value. If unable to locate the key in the message bundle, the key becomes the return value.

Parameters:

l - the Locale to use for rendering the table description

Returns:

java.lang.String