com.objectwave.persist.constraints
Class ConstraintIsNull

java.lang.Object
  |
  +--com.objectwave.persist.constraints.Constraint
        |
        +--com.objectwave.persist.constraints.ConstraintIsNull

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

public class ConstraintIsNull

extends Constraint

Author:

Steven Sinclair

See Also:

Serialized Form

Field Summary

Fields inherited from class com.objectwave.persist.constraints.Constraint

columnName, defaultObjectFormatter, objectFormatter

Constructor Summary

ConstraintIsNull()

Method Summary

boolean	checkConstraint(java.lang.Object fieldObject, java.lang.Object queryObject) This method was created in VisualAge.
java.lang.String	constructQueryString() Return the string which will appear in the query string.
void	fromString(java.lang.String str) Parse the string.
static java.util.Vector	getFields()
java.util.Enumeration	getStaticList() Gets the StaticList attribute of the Constraint object
java.lang.String	getType() This is a unique, readable string identifying the constraint type (ex, anyof, null)
void	staticListInsert(java.lang.String field) Each type of constraint will have a specific set of fields associated with it.
java.lang.String	stringify() Stringify the object.

Methods inherited from class com.objectwave.persist.constraints.Constraint

checkConstraint, classOfField, clone, equals, findField, formatString, getColumnName, getField, getNot, getObjectFormatter, getPersistence, isComparisonValueFromPersistentObject, isUsingColumnName, setColumnName, setField, setNot, setObjectFormatter, setPersistence, sqlString, stringToObject, toString

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ConstraintIsNull

public ConstraintIsNull()

Method Detail

checkConstraint

public boolean checkConstraint(java.lang.Object fieldObject,
                               java.lang.Object queryObject)

This method was created in VisualAge.

Specified by:

checkConstraint in class Constraint

Parameters:

fieldObject - java.lang.Object

queryObject - java.lang.Object

Returns:

boolean

constructQueryString

public java.lang.String constructQueryString()

Description copied from class: Constraint

Return the string which will appear in the query string. That is, what should follow the field specification? (ex, "NOT IN ('cat','dog')"). If this constraint is simply an operator, and the original comparison value should go on the RHS, then the last character should be a '*'. Ex, If the field is "quote.status", and the field' value has been specified to be "Q%", then returning "MATCHES*" will produce "quote.status MATCHES Q%". Ex, Using the above example, returning "NOT IN ('cat','dog')" will produce "quote.status NOT IN ('cat','dog')". Note that the returned string is never padded with spaces. Note that this method will return null if the string cannot be constructed for some reason (an messafe will already have been presented to the user. Perhaps I should delegate that responsability to the calling method... hmmm....)

Specified by:

constructQueryString in class Constraint

Returns:

fromString

public void fromString(java.lang.String str)
                throws java.text.ParseException

Description copied from class: Constraint

Parse the string. Probably a string encoded via the toString() call, this method attempts to build the object's state from the information in string "str".

Specified by:

fromString in class Constraint

Parameters:

str -

Throws:

java.text.ParseException

getFields

public static java.util.Vector getFields()

getStaticList

public java.util.Enumeration getStaticList()

Description copied from class: Constraint

Gets the StaticList attribute of the Constraint object

Specified by:

getStaticList in class Constraint

Returns:

The StaticList value

getType

public java.lang.String getType()

Description copied from class: Constraint

This is a unique, readable string identifying the constraint type (ex, anyof, null)

Specified by:

getType in class Constraint

Returns:

The Type value

staticListInsert

public void staticListInsert(java.lang.String field)

Description copied from class: Constraint

Each type of constraint will have a specific set of fields associated with it. This is to allow the user to select them via Gui.

Specified by:

staticListInsert in class Constraint

Parameters:

field -

stringify

public java.lang.String stringify()

Description copied from class: Constraint

Stringify the object. Object serialization may be a better approach. Oh well. Encode the class's type and state in a readable string.

Specified by:

stringify in class Constraint

Returns: