org.apache.derby.iapi.types
Class UserType

java.lang.Object
  org.apache.derby.iapi.types.DataType
      org.apache.derby.iapi.types.UserType

All Implemented Interfaces:

CloneableObject, DataValueDescriptor, java.io.Externalizable, Formatable, Orderable, java.io.Serializable, Storable, TypedFormat, UserDataValue

Direct Known Subclasses:

UTF

public class UserType

extends DataType

implements UserDataValue

This contains an instance of a user-defined type, that is, a java object.

See Also:

Serialized Form

Field Summary

private static int	BASE_MEMORY_USAGE
private java.lang.Object	value

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

Constructor Summary

UserType()
no-arg constructor required by Formattable

UserType(java.lang.Object value)

Method Summary

int	compare(DataValueDescriptor other) Orderable interface
boolean	compare(int op, DataValueDescriptor other, boolean orderedNulls, boolean unknownRV) Compare this Orderable with a given Orderable for the purpose of qualification and sorting.
BooleanDataValue	equals(DataValueDescriptor left, DataValueDescriptor right) The = operator as called from the language module, as opposed to the storage module.
int	estimateMemoryUsage() Estimate the memory usage in bytes of the data value and the overhead of the class.
boolean	getBoolean() Gets the value in the data value descriptor as a boolean.
byte	getByte() Gets the value in the data value descriptor as a byte.
byte[]	getBytes() Gets the value in the data value descriptor as a byte array.
DataValueDescriptor	getClone() Clone this DataValueDescriptor.
java.sql.Date	getDate(java.util.Calendar cal) Gets the value in the data value descriptor as a java.sql.Date.
double	getDouble() Gets the value in the data value descriptor as a double.
float	getFloat() Gets the value in the data value descriptor as a float.
int	getInt() Gets the value in the data value descriptor as an int.
int	getLength() Gets the length of the data value.
long	getLong() Gets the value in the data value descriptor as a long.
DataValueDescriptor	getNewNull() Get a new null value of the same type as this data value.
java.lang.Object	getObject() Gets the value in the data value descriptor as a Java Object.
short	getShort() Gets the value in the data value descriptor as a short.
java.lang.String	getString() Gets the value in the data value descriptor as a String.
java.sql.Time	getTime(java.util.Calendar cal) Gets the value in the data value descriptor as a java.sql.Time.
java.sql.Timestamp	getTimestamp(java.util.Calendar cal) Gets the value in the data value descriptor as a java.sql.Timestamp.
int	getTypeFormatId() Return my format identifier.
java.lang.String	getTypeName() Get the SQL name of the datatype
int	hashCode()
boolean	isNull() Check if the value is null.
BooleanDataValue	notEquals(DataValueDescriptor left, DataValueDescriptor right) The <> operator as called from the language module, as opposed to the storage module.
void	readExternal(java.io.ObjectInput in)
void	readExternalFromArray(ArrayInputStream in) Read the DataValueDescriptor from the stream.
void	restoreToNull() Restore this object to its (SQL)null value.
void	setBigDecimal(java.lang.Number theValue) Set this value from an application supplied java.math.BigDecimal.
protected void	setFrom(DataValueDescriptor theValue)
void	setObjectForCast(java.lang.Object theValue, boolean instanceOfResultType, java.lang.String resultTypeClassName) Set the Object that this Data Type contains (for an explicit cast).
void	setValue(java.lang.Object value) Set the value of this UserDataValue to the given Object
void	setValue(java.lang.String theValue) Set the value of this DataValueDescriptor.
void	setValueFromResultSet(java.sql.ResultSet resultSet, int colNumber, boolean isNullable) Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.
java.lang.String	toString()
int	typePrecedence() Each built-in type in JSQL has a precedence.
void	writeExternal(java.io.ObjectOutput out)

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

checkHostVariable, cloneObject, coalesce, dataTypeConversion, equals, flip, genericSetObject, getNationalString, getStream, greaterOrEquals, greaterThan, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, outOfRange, setInto, setInto, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, throwLangSetMismatch, typeToBigDecimal

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, getStream, greaterOrEquals, greaterThan, in, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, setInto, setInto, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typeToBigDecimal

Field Detail

value

private java.lang.Object value

BASE_MEMORY_USAGE

private static final int BASE_MEMORY_USAGE

Constructor Detail

UserType

public UserType()

no-arg constructor required by Formattable

UserType

public UserType(java.lang.Object value)

Method Detail

estimateMemoryUsage

public int estimateMemoryUsage()

Description copied from interface: DataValueDescriptor

Estimate the memory usage in bytes of the data value and the overhead of the class.

Specified by:

estimateMemoryUsage in interface DataValueDescriptor

Returns:

the estimated memory usage

getString

public java.lang.String getString()

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.

Specified by:

getString in interface DataValueDescriptor

Returns:

The data value as a String.

getBoolean

public boolean getBoolean()
                   throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a boolean. Throws an exception if the data value is not a boolean. For DataValueDescriptor, this is the preferred interface for BIT, but for this no-casting interface, it isn't, because BIT is stored internally as a Bit, not as a Boolean.

Specified by:

getBoolean in interface DataValueDescriptor

Overrides:

getBoolean in class DataType

Returns:

The data value as a boolean.

Throws:

StandardException - thrown on failure to convert

getByte

public byte getByte()
             throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a byte. Throws an exception if the data value is not a byte.

Specified by:

getByte in interface DataValueDescriptor

Overrides:

getByte in class DataType

Returns:

The data value as a byte.

Throws:

StandardException - thrown on failure to convert

getShort

public short getShort()
               throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a short. Throws an exception if the data value is not a short.

Specified by:

getShort in interface DataValueDescriptor

Overrides:

getShort in class DataType

Returns:

The data value as a short.

Throws:

StandardException - thrown on failure to convert

getInt

public int getInt()
           throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as an int. Throws an exception if the data value is not an int.

Specified by:

getInt in interface DataValueDescriptor

Overrides:

getInt in class DataType

Returns:

The data value as a int.

Throws:

StandardException - thrown on failure to convert

getLong

public long getLong()
             throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a long. Throws an exception if the data value is not a long.

Specified by:

getLong in interface DataValueDescriptor

Overrides:

getLong in class DataType

Returns:

The data value as a long.

Throws:

StandardException - thrown on failure to convert

getFloat

public float getFloat()
               throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a float. Throws an exception if the data value is not a float.

Specified by:

getFloat in interface DataValueDescriptor

Overrides:

getFloat in class DataType

Returns:

The data value as a float.

Throws:

StandardException - thrown on failure to convert

getDouble

public double getDouble()
                 throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a double. Throws an exception if the data value is not a double.

Specified by:

getDouble in interface DataValueDescriptor

Overrides:

getDouble in class DataType

Returns:

The data value as a double.

Throws:

StandardException - thrown on failure to convert

getBytes

public byte[] getBytes()
                throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a byte array. Throws an exception if the data value is not a byte array.

Specified by:

getBytes in interface DataValueDescriptor

Overrides:

getBytes in class DataType

Returns:

The Binary value as a byte[].

Throws:

StandardException - thrown on failure to convert

getDate

public java.sql.Date getDate(java.util.Calendar cal)
                      throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a java.sql.Date. Throws an exception if the data value is not a Date.

Specified by:

getDate in interface DataValueDescriptor

Overrides:

getDate in class DataType

Parameters:

cal - calendar for object creation

Returns:

The data value as a java.sql.Date.

Throws:

StandardException - thrown on failure

getTime

public java.sql.Time getTime(java.util.Calendar cal)
                      throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a java.sql.Time. Throws an exception if the data value is not a Time.

Specified by:

getTime in interface DataValueDescriptor

Overrides:

getTime in class DataType

Parameters:

cal - calendar for object creation

Returns:

The data value as a java.sql.Time.

Throws:

StandardException - thrown on failure

getTimestamp

public java.sql.Timestamp getTimestamp(java.util.Calendar cal)
                                throws StandardException

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a java.sql.Timestamp. Throws an exception if the data value is not a Timestamp.

Specified by:

getTimestamp in interface DataValueDescriptor

Overrides:

getTimestamp in class DataType

Parameters:

cal - calendar for object creation

Returns:

The data value as a java.sql.Timestamp.

Throws:

StandardException - thrown on failure

getObject

public java.lang.Object getObject()

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a Java Object. The type of the Object will be the Java object type corresponding to the data value's SQL type. JDBC defines a mapping between Java object types and SQL types - we will allow that to be extended through user type definitions. Throws an exception if the data value is not an object (yeah, right).

Specified by:

getObject in interface DataValueDescriptor

Overrides:

getObject in class DataType

Returns:

The data value as a int.

setObjectForCast

public void setObjectForCast(java.lang.Object theValue,
                             boolean instanceOfResultType,
                             java.lang.String resultTypeClassName)
                      throws StandardException

Description copied from interface: DataValueDescriptor

Set the Object that this Data Type contains (for an explicit cast).

Specified by:

setObjectForCast in interface DataValueDescriptor

Overrides:

setObjectForCast in class DataType

Returns:

me

Throws:

StandardException - thrown on failure

See Also:

DataValueDescriptor.setObjectForCast(java.lang.Object, boolean, java.lang.String)

getLength

public int getLength()

Description copied from interface: DataValueDescriptor

Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length.

Specified by:

getLength in interface DataValueDescriptor

Returns:

The length of the data value

getTypeName

public java.lang.String getTypeName()

Description copied from interface: DataValueDescriptor

Get the SQL name of the datatype

Specified by:

getTypeName in interface DataValueDescriptor

Returns:

The SQL name of the datatype

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Specified by:

getTypeFormatId in interface TypedFormat

Returns:

The identifier. (A UUID stuffed in an array of 16 bytes).

See Also:

TypedFormat.getTypeFormatId()

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException - error writing data

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException - Thrown on error reading the object

java.lang.ClassNotFoundException - Thrown if the class of the object is not found

See Also:

Externalizable.readExternal(java.io.ObjectInput)

readExternalFromArray

public void readExternalFromArray(ArrayInputStream in)
                           throws java.io.IOException,
                                  java.lang.ClassNotFoundException

Description copied from interface: DataValueDescriptor

Read the DataValueDescriptor from the stream.

Initialize the data value by reading it's values from the ArrayInputStream. This interface is provided as a way to achieve possible performance enhancement when reading an array can be optimized over reading from a generic stream from readExternal().

Specified by:

readExternalFromArray in interface DataValueDescriptor

Parameters:

in - The array stream positioned at the beginning of the byte stream to read from.

Throws:

java.lang.ClassNotFoundException - If a necessary class can not be found while reading the object from the stream.

java.io.IOException - Usual error is if you try to read past limit on the stream.

getClone

public DataValueDescriptor getClone()

Description copied from interface: DataValueDescriptor

Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently.

Specified by:

getClone in interface DataValueDescriptor

Returns:

A clone of the DataValueDescriptor with the same initial value as this.

See Also:

DataValueDescriptor.getClone()

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

See Also:

DataValueDescriptor.getNewNull()

restoreToNull

public void restoreToNull()

Description copied from interface: Storable

Restore this object to its (SQL)null value.

Specified by:

restoreToNull in interface Storable

See Also:

Storable.restoreToNull()

setValueFromResultSet

public void setValueFromResultSet(java.sql.ResultSet resultSet,
                                  int colNumber,
                                  boolean isNullable)
                           throws java.sql.SQLException

Description copied from interface: DataValueDescriptor

Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

Specified by:

setValueFromResultSet in interface DataValueDescriptor

Parameters:

resultSet - The specified ResultSet.

colNumber - The 1-based column # into the resultSet.

isNullable - Whether or not the column is nullable (No need to call wasNull() if not)

Returns:

Nothing.

Throws:

java.sql.SQLException - Thrown on error

See Also:

DataValueDescriptor.setValueFromResultSet(java.sql.ResultSet, int, boolean)

compare

public int compare(DataValueDescriptor other)
            throws StandardException

Orderable interface

Specified by:

compare in interface DataValueDescriptor

Parameters:

other - The Orderable to compare this one to.

Returns:

<0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1.

Throws:

StandardException - thrown on failure

See Also:

Orderable

compare

public boolean compare(int op,
                       DataValueDescriptor other,
                       boolean orderedNulls,
                       boolean unknownRV)
                throws StandardException

Description copied from interface: DataValueDescriptor

Compare this Orderable with a given Orderable for the purpose of qualification and sorting. The caller gets to determine how nulls should be treated - they can either be ordered values or unknown values.

Specified by:

compare in interface DataValueDescriptor

Overrides:

compare in class DataType

Throws:

StandardException - thrown on error

setValue

public void setValue(java.lang.Object value)

Description copied from interface: UserDataValue

Set the value of this UserDataValue to the given Object

Specified by:

setValue in interface UserDataValue

Overrides:

setValue in class DataType

See Also:

UserDataValue.setValue(java.lang.Object)

setFrom

protected void setFrom(DataValueDescriptor theValue)
                throws StandardException

Overrides:

setFrom in class DataType

Throws:

StandardException

setBigDecimal

public void setBigDecimal(java.lang.Number theValue)

Description copied from interface: DataValueDescriptor

Set this value from an application supplied java.math.BigDecimal. This is to support the PreparedStatement.setBigDecimal method and similar JDBC methods that allow an application to pass in a BigDecimal to any SQL type. Parameter is declared as java.lang.Number to allow compilation under J2ME/CDC/Foundation. This method will not be called in any environment that does not support java.math.BigDecimal.

Specified by:

setBigDecimal in interface DataValueDescriptor

Overrides:

setBigDecimal in class DataType

See Also:

UserDataValue.setValue(java.lang.Object)

setValue

public void setValue(java.lang.String theValue)

Description copied from interface: DataValueDescriptor

Set the value of this DataValueDescriptor.

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The BigDecimal value to set this DataValueDescriptor to

Returns:

This DataValueDescriptor

equals

public BooleanDataValue equals(DataValueDescriptor left,
                               DataValueDescriptor right)
                        throws StandardException

The = operator as called from the language module, as opposed to the storage module.

Specified by:

equals in interface DataValueDescriptor

Overrides:

equals in class DataType

Parameters:

left - The value on the left side of the =

right - The value on the right side of the =

Returns:

A SQL boolean value telling whether the two parameters are equal

Throws:

StandardException - Thrown on error

notEquals

public BooleanDataValue notEquals(DataValueDescriptor left,
                                  DataValueDescriptor right)
                           throws StandardException

The <> operator as called from the language module, as opposed to the storage module.

Specified by:

notEquals in interface DataValueDescriptor

Overrides:

notEquals in class DataType

Parameters:

left - The value on the left side of the <>

right - The value on the right side of the <>

Returns:

A SQL boolean value telling whether the two parameters are not equal

Throws:

StandardException - Thrown on error

toString

public java.lang.String toString()

hashCode

public int hashCode()

typePrecedence

public int typePrecedence()

Description copied from interface: DataValueDescriptor

Each built-in type in JSQL has a precedence. This precedence determines how to do type promotion when using binary operators. For example, float has a higher precedence than int, so when adding an int to a float, the result type is float. The precedence for some types is arbitrary. For example, it doesn't matter what the precedence of the boolean type is, since it can't be mixed with other types. But the precedence for the number types is critical. The SQL standard requires that exact numeric types be promoted to approximate numeric when one operator uses both. Also, the precedence is arranged so that one will not lose precision when promoting a type.

Specified by:

typePrecedence in interface DataValueDescriptor

Overrides:

typePrecedence in class DataType

Returns:

The precedence of this type.

See Also:

DataValueDescriptor.typePrecedence()

isNull

public final boolean isNull()

Check if the value is null.

Specified by:

isNull in interface Storable

Returns:

Whether or not value is logically null.