org.apache.derby.iapi.types

Class CollatorSQLClob

java.lang.Object

org.apache.derby.iapi.types.DataType

org.apache.derby.iapi.types.SQLChar

org.apache.derby.iapi.types.SQLVarchar

org.apache.derby.iapi.types.SQLClob

org.apache.derby.iapi.types.CollatorSQLClob

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Comparable, Formatable, Storable, StreamStorable, TypedFormat, CollationElementsInterface, ConcatableDataValue, DataValueDescriptor, Orderable, StringDataValue, VariableSizeDataValue

class CollatorSQLClob
extends SQLClob
implements CollationElementsInterface

CollatorSQLClob class differs from SQLClob based on how the 2 classes use different collations to collate their data. SQLClob uses Derby's default collation which is UCS_BASIC. Whereas, this class uses the RuleBasedCollator object that was passed to it in it's constructor and that RuleBasedCollator object decides the collation. In Derby 10.3, this class will be passed a RuleBasedCollator which is based on the database's territory. In future releases of Derby, this class can be used to do other kinds of collations like case-insensitive collation etc by just passing an appropriate RuleBasedCollator object for that kind of collation.

Field Summary

Fields

Modifier and Type	Field and Description
private WorkHorseForCollatorDatatypes	holderForCollationSensitiveInfo

Fields inherited from class org.apache.derby.iapi.types.SQLChar

_clobValue, arg_passer, CHAR_HEADER_GENERATOR, RETURN_SPACE_THRESHOLD, stream

Fields inherited from interface org.apache.derby.iapi.types.StringDataValue

BOTH, COLLATION_DERIVATION_EXPLICIT, COLLATION_DERIVATION_IMPLICIT, COLLATION_DERIVATION_NONE, COLLATION_TYPE_TERRITORY_BASED, COLLATION_TYPE_TERRITORY_BASED_IDENTICAL, COLLATION_TYPE_TERRITORY_BASED_PRIMARY, COLLATION_TYPE_TERRITORY_BASED_SECONDARY, COLLATION_TYPE_TERRITORY_BASED_TERTIARY, COLLATION_TYPE_UCS_BASIC, LEADING, TRAILING

Fields inherited from interface org.apache.derby.iapi.types.DataValueDescriptor

UNKNOWN_LOGICAL_LENGTH

Fields inherited from interface org.apache.derby.iapi.types.Orderable

ORDER_OP_EQUALS, ORDER_OP_GREATEROREQUALS, ORDER_OP_GREATERTHAN, ORDER_OP_LESSOREQUALS, ORDER_OP_LESSTHAN

Fields inherited from interface org.apache.derby.iapi.types.VariableSizeDataValue

IGNORE_PRECISION

Constructor Summary

Constructors

Constructor and Description
CollatorSQLClob(java.sql.Clob val, java.text.RuleBasedCollator collatorForCharacterDatatypes) Create SQL CLOB value initially set to value that performs collation according to collatorForCharacterDatatypes
CollatorSQLClob(java.text.RuleBasedCollator collatorForCharacterDatatypes) Create SQL CLOB value initially set to NULL that performs collation according to collatorForCharacterDatatypes
CollatorSQLClob(java.lang.String val, java.text.RuleBasedCollator collatorForCharacterDatatypes) Create SQL CLOB value initially set to value that performs collation according to collatorForCharacterDatatypes

Method Summary

Modifier and Type	Method and Description
DataValueDescriptor	cloneValue(boolean forceMaterialization) Returns a clone of this CLOB value.
protected java.text.RuleBasedCollator	getCollatorForCollation() Get the RuleBasedCollator for this instance of CollatorSQLClob.
DataValueDescriptor	getNewNull() Get a new null value of the same type as this data value.
StringDataValue	getValue(java.text.RuleBasedCollator collatorForComparison) We do not anticipate this method on collation sensitive DVD to be ever called in Derby 10.3 In future, when Derby will start supporting SQL standard COLLATE clause, this method might get called on the collation sensitive DVDs.
int	hashCode() Return a hash code that is consistent with stringCompare(SQLChar, SQLChar).
boolean	hasSingleCollationElement() Check if this instance represents a value that has a single collation element.
BooleanDataValue	like(DataValueDescriptor pattern) This method implements the like function for char (with no escape value).
BooleanDataValue	like(DataValueDescriptor pattern, DataValueDescriptor escape) This method implements the like function for char with an escape value.
private void	setCollator(java.text.RuleBasedCollator collatorForCharacterDatatypes) Set the RuleBasedCollator for this instance of CollatorSQLClob.
protected int	stringCompare(SQLChar char1, SQLChar char2) Compare two SQLChars.

Methods inherited from class org.apache.derby.iapi.types.SQLClob

getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLength, getLong, getObject, getShort, getStreamHeaderGenerator, getStreamWithDescriptor, getTime, getTimestamp, getTraceString, getTypeFormatId, getTypeName, hasStream, normalize, readExternal, readExternalFromArray, restoreToNull, setBigDecimal, setObject, setStream, setStreamHeaderFormat, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typePrecedence, typeToBigDecimal, writeExternal

Methods inherited from class org.apache.derby.iapi.types.SQLVarchar

growBy, normalize

Methods inherited from class org.apache.derby.iapi.types.SQLChar

ansiTrim, charLength, cloneHolder, compare, compare, concatenate, copyState, equals, estimateMemoryUsage, getCharArray, getCollationKey, getDate, getLocaleFinder, getNewVarchar, getRawDataAndZeroIt, getStream, getString, getTime, getTimestamp, greaterOrEquals, greaterThan, hashCodeForCollation, hasNonBlankChars, isNull, lessOrEquals, lessThan, loadStream, locate, lower, notEquals, readExternal, readExternalClobFromArray, returnStream, setFrom, setInto, setLocaleFinder, setObjectForCast, setValue, setValue, setValue, setValueFromResultSet, setWidth, stringCompare, stringCompare, substring, throwStreamingIOException, toString, upper, writeClobUTF, zeroRawData

Methods inherited from class org.apache.derby.iapi.types.DataType

checkHostVariable, coalesce, compare, compare, compareTo, dataTypeConversion, equals, flip, genericSetObject, getTypeName, in, invalidFormat, isNotNull, isNullOp, outOfRange, recycle, setInto, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, throwLangSetMismatch

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.derby.iapi.types.DataValueDescriptor

checkHostVariable, coalesce, compare, compare, in, isNotNull, isNullOp, recycle, setInto, setToNull, setValue, setValue, setValue, setValue, setValue, setValue

Field Detail

holderForCollationSensitiveInfo

private WorkHorseForCollatorDatatypes holderForCollationSensitiveInfo

Constructor Detail

CollatorSQLClob

CollatorSQLClob(java.text.RuleBasedCollator collatorForCharacterDatatypes)

Create SQL CLOB value initially set to NULL that performs collation according to collatorForCharacterDatatypes

CollatorSQLClob

CollatorSQLClob(java.lang.String val,
                java.text.RuleBasedCollator collatorForCharacterDatatypes)

Create SQL CLOB value initially set to value that performs collation according to collatorForCharacterDatatypes

CollatorSQLClob

CollatorSQLClob(java.sql.Clob val,
                java.text.RuleBasedCollator collatorForCharacterDatatypes)

Create SQL CLOB value initially set to value that performs collation according to collatorForCharacterDatatypes

Method Detail

setCollator

private void setCollator(java.text.RuleBasedCollator collatorForCharacterDatatypes)

Set the RuleBasedCollator for this instance of CollatorSQLClob. It will be used to do the collation.

getCollatorForCollation

protected java.text.RuleBasedCollator getCollatorForCollation()
                                                       throws StandardException

Get the RuleBasedCollator for this instance of CollatorSQLClob. It will be used to do the collation.

Overrides:

getCollatorForCollation in class SQLChar

Returns:

The Collator object which should be used for collation operation on this object

Throws:

StandardException

hasSingleCollationElement

public boolean hasSingleCollationElement()
                                  throws StandardException

Description copied from interface: CollationElementsInterface

Check if this instance represents a value that has a single collation element.

Specified by:

hasSingleCollationElement in interface CollationElementsInterface

Returns:

true if the value has exactly one collation element, or false otherwise

Throws:

StandardException - if an error occurs when accessing the value

cloneValue

public DataValueDescriptor cloneValue(boolean forceMaterialization)

Description copied from class: SQLClob

Returns a clone of this CLOB value.

Unlike the other binary types, CLOBs can be very large. We try to clone the underlying stream when possible to avoid having to materialize the value into memory.

Specified by:

cloneValue in interface DataValueDescriptor

Overrides:

cloneValue in class SQLClob

Parameters:

forceMaterialization - any streams representing the data value will be materialized if true, the data value will be kept as a stream if possible if false

Returns:

A clone of this CLOB value.

See Also:

DataValueDescriptor.cloneValue(boolean)

getNewNull

public DataValueDescriptor getNewNull()

Description copied from interface: DataValueDescriptor

Get a new null value of the same type as this data value.

Specified by:

getNewNull in interface DataValueDescriptor

Overrides:

getNewNull in class SQLClob

See Also:

DataValueDescriptor.getNewNull()

getValue

public StringDataValue getValue(java.text.RuleBasedCollator collatorForComparison)

We do not anticipate this method on collation sensitive DVD to be ever called in Derby 10.3 In future, when Derby will start supporting SQL standard COLLATE clause, this method might get called on the collation sensitive DVDs.

Specified by:

getValue in interface StringDataValue

Overrides:

getValue in class SQLClob

See Also:

StringDataValue.getValue(RuleBasedCollator)

stringCompare

protected int stringCompare(SQLChar char1,
                            SQLChar char2)
                     throws StandardException

Description copied from class: SQLChar

Compare two SQLChars.

Overrides:

stringCompare in class SQLChar

Throws:

StandardException - Thrown on error

See Also:

SQLChar.stringCompare(SQLChar, SQLChar)

hashCode

public int hashCode()

Return a hash code that is consistent with stringCompare(SQLChar, SQLChar).

Overrides:

hashCode in class SQLChar

Returns:

hash code

like

public BooleanDataValue like(DataValueDescriptor pattern)
                      throws StandardException

This method implements the like function for char (with no escape value). The difference in this method and the same method in superclass is that here we use special Collator object to do the comparison rather than using the Collator object associated with the default jvm locale.

Specified by:

like in interface StringDataValue

Overrides:

like in class SQLChar

Parameters:

pattern - The pattern to use

Returns:

A SQL boolean value telling whether the first operand is like the second operand

Throws:

StandardException - Thrown on error

like

public BooleanDataValue like(DataValueDescriptor pattern,
                             DataValueDescriptor escape)
                      throws StandardException

This method implements the like function for char with an escape value.

Specified by:

like in interface StringDataValue

Overrides:

like in class SQLChar

Parameters:

pattern - The pattern to use

escape - the escape character

Returns:

A SQL boolean value telling whether the first operand is like the second operand

Throws:

StandardException - Thrown on error