io.delta.kernel.expressions

Class Literal

Object

io.delta.kernel.expressions.Literal

All Implemented Interfaces:

Expression

@Evolving
public final class Literal
extends Object
implements Expression

A literal value.

Definition:

• Represents literal of primitive types as defined in the protocol Delta Transaction Log Protocol: Primitive Types
• Use getValue() to fetch the literal value. Returned value type depends on the type of the literal data type. See the getValue() for further details.

Since:

3.0.0

Method Summary

Modifier and Type	Method and Description
java.util.List<Expression>	getChildren()
DataType	getDataType() Get the datatype of the literal object.
Object	getValue() Get the literal value.
static Literal	ofBinary(byte[] value) Create a binary type literal expression.
static Literal	ofBoolean(boolean value) Create a boolean type literal expression.
static Literal	ofByte(byte value) Create a byte type literal expression.
static Literal	ofDate(int daysSinceEpochUTC) Create a date type literal expression.
static Literal	ofDecimal(java.math.BigDecimal value, int precision, int scale) Create a decimal type literal expression.
static Literal	ofDouble(double value) Create a double type literal expression.
static Literal	ofFloat(float value) Create a float type literal expression.
static Literal	ofInt(int value) Create a integer type literal expression.
static Literal	ofLong(long value) Create a long type literal expression.
static Literal	ofNull(DataType dataType) Create null value literal.
static Literal	ofShort(short value) Create a short type literal expression.
static Literal	ofString(String value) Create a string type literal expression.
static Literal	ofTimestamp(long microsSinceEpochUTC) Create a timestamp type literal expression.
String	toString()

Methods inherited from class Object

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

Method Detail

ofBoolean

public static Literal ofBoolean(boolean value)

Create a boolean type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type BooleanType

ofByte

public static Literal ofByte(byte value)

Create a byte type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type ByteType

ofShort

public static Literal ofShort(short value)

Create a short type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type ShortType

ofInt

public static Literal ofInt(int value)

Create a integer type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type IntegerType

ofLong

public static Literal ofLong(long value)

Create a long type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type LongType

ofFloat

public static Literal ofFloat(float value)

Create a float type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type FloatType

ofDouble

public static Literal ofDouble(double value)

Create a double type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type DoubleType

ofString

public static Literal ofString(String value)

Create a string type literal expression.

Parameters:

value - literal value

Returns:

a Literal of type StringType

ofBinary

public static Literal ofBinary(byte[] value)

Create a binary type literal expression.

Parameters:

value - binary literal value as an array of bytes

Returns:

a Literal of type BinaryType

ofDate

public static Literal ofDate(int daysSinceEpochUTC)

Create a date type literal expression.

Parameters:

daysSinceEpochUTC - number of days since the epoch in UTC timezone.

Returns:

a Literal of type DateType

ofTimestamp

public static Literal ofTimestamp(long microsSinceEpochUTC)

Create a timestamp type literal expression.

Parameters:

microsSinceEpochUTC - microseconds since epoch time in UTC timezone.

Returns:

a Literal with data type TimestampType

ofDecimal

public static Literal ofDecimal(java.math.BigDecimal value,
                                int precision,
                                int scale)

Create a decimal type literal expression.

Parameters:

value - decimal literal value

precision - precision of the decimal literal

scale - scale of the decimal literal

Returns:

a Literal with data type DecimalType with given precision and scale.

ofNull

public static Literal ofNull(DataType dataType)

Create null value literal.

Parameters:

dataType - DataType of the null literal.

Returns:

a null Literal with the given data type

getValue

public Object getValue()

Get the literal value. If the value is null a null is returned. For non-null literal the returned value is one of the following types based on the literal data type.

• BOOLEAN: Boolean
• BYTE: Byte
• SHORT: Short
• INTEGER: Integer
• LONG: Long
• FLOAT: Float
• DOUBLE: Double
• DATE: Integer represents the number of days since epoch in UTC
• TIMESTAMP: Long represents the microseconds since epoch in UTC
• DECIMAL: BigDecimal.Use getDataType() to find the precision and scale

Returns:

Literal value.

getDataType

public DataType getDataType()

Get the datatype of the literal object. Datatype lets the caller interpret the value of the literal object returned by getValue()

Returns:

Datatype of the literal object.

toString

public String toString()

Overrides:

toString in class Object

getChildren

public java.util.List<Expression> getChildren()

Specified by:

getChildren in interface Expression

Returns:

a list of expressions that are input to this expression.