com.healthmarketscience.jackcess
Class Column

java.lang.Object
  com.healthmarketscience.jackcess.Column

All Implemented Interfaces:

Comparable<Column>

public class Column
extends Object
implements Comparable<Column>

Access database column definition

Author:

Tim McCune

Field Summary

static Object	AUTO_NUMBER Meaningless placeholder object for inserting values in an autonumber column.
static byte	AUTO_NUMBER_FLAG_MASK mask for the auto number bit
static byte	FIXED_LEN_FLAG_MASK mask for the fixed len bit
static byte	UNKNOWN_FLAG_MASK mask for the unknown bit

Constructor Summary

Column()

Column(JetFormat format)

Column(Table table, ByteBuffer buffer, int offset)
Read a column definition in from a buffer

Method Summary

int	compareTo(Column other)
static short	countNonLongVariableLength(List<Column> columns)
static short	countVariableLength(List<Column> columns)
static String	decodeUncompressedText(byte[] textBytes, JetFormat format)
static ByteBuffer	encodeUncompressedText(CharSequence text, JetFormat format)
int	getColumnIndex()
short	getColumnNumber()
int	getFixedDataOffset()
JetFormat	getFormat()
short	getLength()
short	getLengthInUnits()
String	getName()
PageChannel	getPageChannel()
byte	getPrecision()
byte	getScale()
int	getSQLType()
Table	getTable()
DataType	getType()
int	getVarLenTableIndex()
boolean	isAutoNumber()
boolean	isCompressedUnicode()
boolean	isVariableLength()
Object	read(byte[] data) Deserialize a raw byte value for this column into an Object
Object	read(byte[] data, ByteOrder order) Deserialize a raw byte value for this column into an Object
void	setAutoNumber(boolean autoNumber)
void	setColumnIndex(int newColumnIndex)
void	setColumnNumber(short newColumnNumber)
void	setFixedDataOffset(int newOffset)
void	setLength(short length)
void	setLengthInUnits(short unitLength)
void	setName(String name)
void	setPrecision(byte newPrecision)
void	setScale(byte newScale)
void	setSQLType(int type)
void	setSQLType(int type, int lengthInUnits)
void	setType(DataType type) Also sets the length and the variable length flag, inferred from the type.
void	setVariableLength(boolean variableLength)
void	setVarLenTableIndex(int idx)
static boolean	toBooleanValue(Object obj) Interpret a boolean value (null == false)
static CharSequence	toCharSequence(Object value)
String	toString()
void	validate(JetFormat format) Checks that this column definition is valid.
ByteBuffer	write(Object obj, int remainingRowLength) Serialize an Object into a raw byte value for this column in little endian order
ByteBuffer	write(Object obj, int remainingRowLength, ByteOrder order) Serialize an Object into a raw byte value for this column
ByteBuffer	writeFixedLengthField(Object obj, ByteOrder order) Serialize an Object into a raw byte value for this column
ByteBuffer	writeLongValue(byte[] value, int remainingRowLength) Write an LVAL column into a ByteBuffer inline if it fits, otherwise in other data page(s).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

AUTO_NUMBER

public static final Object AUTO_NUMBER

Meaningless placeholder object for inserting values in an autonumber column. it is not required that this value be used (any passed in value is ignored), but using this placeholder may make code more obvious.

FIXED_LEN_FLAG_MASK

public static final byte FIXED_LEN_FLAG_MASK

mask for the fixed len bit

See Also:

Constant Field Values

AUTO_NUMBER_FLAG_MASK

public static final byte AUTO_NUMBER_FLAG_MASK

mask for the auto number bit

See Also:

Constant Field Values

UNKNOWN_FLAG_MASK

public static final byte UNKNOWN_FLAG_MASK

mask for the unknown bit

See Also:

Constant Field Values

Constructor Detail

Column

public Column()

Column

public Column(JetFormat format)

Column

public Column(Table table,
              ByteBuffer buffer,
              int offset)
       throws IOException

Read a column definition in from a buffer

Parameters:

table - owning table

buffer - Buffer containing column definition

offset - Offset in the buffer at which the column definition starts

Throws:

IOException

Method Detail

getTable

public Table getTable()

getFormat

public JetFormat getFormat()

getPageChannel

public PageChannel getPageChannel()

getName

public String getName()

setName

public void setName(String name)

isVariableLength

public boolean isVariableLength()

setVariableLength

public void setVariableLength(boolean variableLength)

isAutoNumber

public boolean isAutoNumber()

setAutoNumber

public void setAutoNumber(boolean autoNumber)

getColumnNumber

public short getColumnNumber()

setColumnNumber

public void setColumnNumber(short newColumnNumber)

getColumnIndex

public int getColumnIndex()

setColumnIndex

public void setColumnIndex(int newColumnIndex)

setType

public void setType(DataType type)

Also sets the length and the variable length flag, inferred from the type. For types with scale/precision, sets the scale and precision to default values.

getType

public DataType getType()

getSQLType

public int getSQLType()
               throws SQLException

Throws:

SQLException

setSQLType

public void setSQLType(int type)
                throws SQLException

Throws:

SQLException

setSQLType

public void setSQLType(int type,
                       int lengthInUnits)
                throws SQLException

Throws:

SQLException

isCompressedUnicode

public boolean isCompressedUnicode()

getPrecision

public byte getPrecision()

setPrecision

public void setPrecision(byte newPrecision)

getScale

public byte getScale()

setScale

public void setScale(byte newScale)

setLength

public void setLength(short length)

getLength

public short getLength()

setLengthInUnits

public void setLengthInUnits(short unitLength)

getLengthInUnits

public short getLengthInUnits()

setVarLenTableIndex

public void setVarLenTableIndex(int idx)

getVarLenTableIndex

public int getVarLenTableIndex()

setFixedDataOffset

public void setFixedDataOffset(int newOffset)

getFixedDataOffset

public int getFixedDataOffset()

validate

public void validate(JetFormat format)

Checks that this column definition is valid.

Throws:

IllegalArgumentException - if this column definition is invalid.

read

public Object read(byte[] data)
            throws IOException

Deserialize a raw byte value for this column into an Object

Parameters:

data - The raw byte value

Returns:

The deserialized Object

Throws:

IOException

read

public Object read(byte[] data,
                   ByteOrder order)
            throws IOException

Deserialize a raw byte value for this column into an Object

Parameters:

data - The raw byte value

order - Byte order in which the raw value is stored

Returns:

The deserialized Object

Throws:

IOException

writeLongValue

public ByteBuffer writeLongValue(byte[] value,
                                 int remainingRowLength)
                          throws IOException

Write an LVAL column into a ByteBuffer inline if it fits, otherwise in other data page(s).

Parameters:

value - Value of the LVAL column

Returns:

A buffer containing the LVAL definition and (possibly) the column value (unless written to other pages)

Throws:

IOException

write

public ByteBuffer write(Object obj,
                        int remainingRowLength)
                 throws IOException

Serialize an Object into a raw byte value for this column in little endian order

Parameters:

obj - Object to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

write

public ByteBuffer write(Object obj,
                        int remainingRowLength,
                        ByteOrder order)
                 throws IOException

Serialize an Object into a raw byte value for this column

Parameters:

obj - Object to serialize

order - Order in which to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

writeFixedLengthField

public ByteBuffer writeFixedLengthField(Object obj,
                                        ByteOrder order)
                                 throws IOException

Serialize an Object into a raw byte value for this column

Parameters:

obj - Object to serialize

order - Order in which to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

decodeUncompressedText

public static String decodeUncompressedText(byte[] textBytes,
                                            JetFormat format)

Parameters:

textBytes - bytes of text to decode

format - relevant db format

Returns:

the decoded string

encodeUncompressedText

public static ByteBuffer encodeUncompressedText(CharSequence text,
                                                JetFormat format)

Parameters:

text - Text to encode

format - relevant db format

Returns:

A buffer with the text encoded

compareTo

public int compareTo(Column other)

Specified by:

compareTo in interface Comparable<Column>

countVariableLength

public static short countVariableLength(List<Column> columns)

Parameters:

columns - A list of columns in a table definition

Returns:

The number of variable length columns found in the list

countNonLongVariableLength

public static short countNonLongVariableLength(List<Column> columns)

Parameters:

columns - A list of columns in a table definition

Returns:

The number of variable length columns which are not long values found in the list

toCharSequence

public static CharSequence toCharSequence(Object value)

Returns:

an appropriate CharSequence representation of the given object.

toBooleanValue

public static boolean toBooleanValue(Object obj)

Interpret a boolean value (null == false)