org.h2.value

Class ValueLobDb

java.lang.Object

org.h2.value.Value

org.h2.value.ValueLobDb

All Implemented Interfaces:

Value.ValueBlob, Value.ValueClob

public class ValueLobDb
extends Value
implements Value.ValueClob, Value.ValueBlob

A implementation of the BLOB and CLOB data types. Small objects are kept in memory and stored in the record. Large objects are either stored in the database, or in temporary files.

Nested Class Summary

Nested classes/interfaces inherited from class org.h2.value.Value

Value.ValueBlob, Value.ValueClob

Field Summary

Fields inherited from class org.h2.value.Value

ARRAY, BLOB, BOOLEAN, BYTE, BYTES, CLOB, DATE, DECIMAL, DOUBLE, FLOAT, GEOMETRY, INT, JAVA_OBJECT, LONG, NULL, RESULT_SET, SHORT, STRING, STRING_FIXED, STRING_IGNORECASE, TIME, TIMESTAMP, TIMESTAMP_TZ, TYPE_COUNT, UNKNOWN, UUID

Method Summary

Methods

Modifier and Type	Method and Description
protected int	compareSecure(Value v, CompareMode mode) Compare the value with another value of the same type.
Value	convertPrecision(long precision, boolean force) Convert the precision to the requested value.
Value	convertTo(int t) Convert a lob to another data type.
Value	copy(DataHandler database, int tableId) Copy a large value, to be used in the given table.
ValueLobDb	copyToResult() Create an independent copy of this value, that will be bound to a result.
ValueLobDb	copyToTemp() Create an independent copy of this temporary value.
static ValueLobDb	create(int type, DataHandler handler, int tableId, long id, byte[] hmac, long precision) Create a LOB value.
static Value	createSmallLob(int type, byte[] small) Create a LOB object that fits in memory.
static ValueLobDb	createSmallLob(int type, byte[] small, long precision) Create a LOB object that fits in memory.
static ValueLobDb	createTempBlob(java.io.InputStream in, long length, DataHandler handler) Create a temporary BLOB value from a stream.
static ValueLobDb	createTempClob(java.io.Reader in, long length, DataHandler handler) Create a temporary CLOB value from a stream.
boolean	equals(java.lang.Object other) Check if the two values have the same hash code.
byte[]	getBytes()
byte[]	getBytesNoCopy()
int	getDisplaySize() Get the display size in characters.
java.io.InputStream	getInputStream()
long	getLobId()
int	getMemory() Get the memory used by this object.
java.lang.Object	getObject() Get the value as an object.
long	getPrecision() Get the precision.
java.io.Reader	getReader()
byte[]	getSmall() Get the data if this a small lob value.
java.lang.String	getSQL() Get the SQL expression for this value.
java.lang.String	getString() Get the value as a string.
int	getTableId() Get the current table id of this lob.
java.lang.String	getTraceSQL() Get a medium size SQL expression for debugging or tracing.
int	getType() Get the value type.
int	hashCode()
boolean	isLinkedToTable() Check if this value is linked to a specific table.
boolean	isStored()
void	remove() Remove the underlying resource, if any.
void	set(java.sql.PreparedStatement prep, int parameterIndex) Set the value as a parameter in a prepared statement.
java.lang.String	toString()

Methods inherited from class org.h2.value.Value

add, checkPrecision, clearCache, compareTo, compareTypeSafe, convertScale, divide, getBigDecimal, getBoolean, getByte, getDataHandler, getDate, getDouble, getFloat, getHigherOrder, getInt, getLong, getResultSet, getScale, getShort, getSignum, getTime, getTimestamp, modulus, multiply, negate, subtract, throwUnsupportedExceptionForType

Methods inherited from class java.lang.Object

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

Method Detail

create

public static ValueLobDb create(int type,
                DataHandler handler,
                int tableId,
                long id,
                byte[] hmac,
                long precision)

Create a LOB value.

Parameters:

type - the type

handler - the data handler

tableId - the table id

id - the lob id

hmac - the message authentication code

precision - the precision (number of bytes / characters)

Returns:

the value

convertTo

public Value convertTo(int t)

Convert a lob to another data type. The data is fully read in memory except when converting to BLOB or CLOB.

Overrides:

convertTo in class Value

Parameters:

t - the new type

Returns:

the converted value

isLinkedToTable

public boolean isLinkedToTable()

Description copied from class: Value

Check if this value is linked to a specific table. For values that are kept fully in memory, this method returns false.

Overrides:

isLinkedToTable in class Value

Returns:

true if it is

isStored

public boolean isStored()

remove

public void remove()

Description copied from class: Value

Remove the underlying resource, if any. For values that are kept fully in memory this method has no effect.

Overrides:

remove in class Value

copy

public Value copy(DataHandler database,
         int tableId)

Description copied from class: Value

Copy a large value, to be used in the given table. For values that are kept fully in memory this method has no effect.

Overrides:

copy in class Value

Parameters:

database - the data handler

tableId - the table where this object is used

Returns:

the new value or itself

getTableId

public int getTableId()

Get the current table id of this lob.

Overrides:

getTableId in class Value

Returns:

the table id

getType

public int getType()

Description copied from class: Value

Get the value type.

Specified by:

getType in class Value

Returns:

the type

getPrecision

public long getPrecision()

Description copied from class: Value

Get the precision.

Specified by:

getPrecision in class Value

Returns:

the precision

getString

public java.lang.String getString()

Description copied from class: Value

Get the value as a string.

Specified by:

getString in class Value

Returns:

the string

getBytes

public byte[] getBytes()

Overrides:

getBytes in class Value

getBytesNoCopy

public byte[] getBytesNoCopy()

Overrides:

getBytesNoCopy in class Value

hashCode

public int hashCode()

Specified by:

hashCode in class Value

compareSecure

protected int compareSecure(Value v,
                CompareMode mode)

Description copied from class: Value

Compare the value with another value of the same type.

Specified by:

compareSecure in class Value

Parameters:

v - the other value

mode - the compare mode

Returns:

0 if both values are equal, -1 if the other value is smaller, and 1 otherwise

getObject

public java.lang.Object getObject()

Description copied from class: Value

Get the value as an object.

Specified by:

getObject in class Value

Returns:

the object

getReader

public java.io.Reader getReader()

Overrides:

getReader in class Value

getInputStream

public java.io.InputStream getInputStream()

Overrides:

getInputStream in class Value

set

public void set(java.sql.PreparedStatement prep,
       int parameterIndex)
         throws java.sql.SQLException

Description copied from class: Value

Set the value as a parameter in a prepared statement.

Specified by:

set in class Value

Parameters:

prep - the prepared statement

parameterIndex - the parameter index

Throws:

java.sql.SQLException

getSQL

public java.lang.String getSQL()

Description copied from class: Value

Get the SQL expression for this value.

Specified by:

getSQL in class Value

Returns:

the SQL expression

getTraceSQL

public java.lang.String getTraceSQL()

Description copied from class: Value

Get a medium size SQL expression for debugging or tracing. If the precision is too large, only a subset of the value is returned.

Overrides:

getTraceSQL in class Value

Returns:

the SQL expression

getSmall

public byte[] getSmall()

Get the data if this a small lob value.

Overrides:

getSmall in class Value

Returns:

the data

getDisplaySize

public int getDisplaySize()

Description copied from class: Value

Get the display size in characters.

Specified by:

getDisplaySize in class Value

Returns:

the display size

equals

public boolean equals(java.lang.Object other)

Description copied from class: Value

Check if the two values have the same hash code. No data conversion is made; this method returns false if the other object is not of the same class. For some values, compareTo may return 0 even if equals return false. Example: ValueDecimal 0.0 and 0.00.

Specified by:

equals in class Value

Parameters:

other - the other value

Returns:

true if they are equal

getMemory

public int getMemory()

Description copied from class: Value

Get the memory used by this object.

Overrides:

getMemory in class Value

Returns:

the memory used in bytes

copyToTemp

public ValueLobDb copyToTemp()

Create an independent copy of this temporary value. The file will not be deleted automatically.

Overrides:

copyToTemp in class Value

Returns:

the value

copyToResult

public ValueLobDb copyToResult()

Create an independent copy of this value, that will be bound to a result.

Overrides:

copyToResult in class Value

Returns:

the value (this for small objects)

getLobId

public long getLobId()

toString

public java.lang.String toString()

Overrides:

toString in class Value

createTempClob

public static ValueLobDb createTempClob(java.io.Reader in,
                        long length,
                        DataHandler handler)

Create a temporary CLOB value from a stream.

Parameters:

in - the reader

length - the number of characters to read, or -1 for no limit

handler - the data handler

Returns:

the lob value

createTempBlob

public static ValueLobDb createTempBlob(java.io.InputStream in,
                        long length,
                        DataHandler handler)

Create a temporary BLOB value from a stream.

Parameters:

in - the input stream

length - the number of characters to read, or -1 for no limit

handler - the data handler

Returns:

the lob value

convertPrecision

public Value convertPrecision(long precision,
                     boolean force)

Description copied from class: Value

Convert the precision to the requested value. The precision of the returned value may be somewhat larger than requested, because values with a fixed precision are not truncated.

Overrides:

convertPrecision in class Value

Parameters:

precision - the new precision

force - true if losing numeric precision is allowed

Returns:

the new value

createSmallLob

public static Value createSmallLob(int type,
                   byte[] small)

Create a LOB object that fits in memory.

Parameters:

type - the type (Value.BLOB or CLOB)

small - the byte array

Returns:

the LOB

createSmallLob

public static ValueLobDb createSmallLob(int type,
                        byte[] small,
                        long precision)

Create a LOB object that fits in memory.

Parameters:

type - the type (Value.BLOB or CLOB)

small - the byte array

precision - the precision

Returns:

the LOB