Package org.opencastproject.assetmanager.api

Class Value

java.lang.Object

org.opencastproject.assetmanager.api.Value

Direct Known Subclasses:

Value.TypedValue

@ParametersAreNonnullByDefault
public abstract class Value
extends Object

A property value.

The wrapped type is not exposed as a generic type parameter since Values appear in contexts like lists where this type information cannot be preserved. To access the wrapped type one can choose between two options. If the type is known, use get(ValueType). If the type is not known, safely decompose the value with decompose(Fn, Fn, Fn, Fn, Fn).

The value type is a sum type made up from

• Value.StringValue
• Value.DateValue
• Value.LongValue
• Value.BooleanValue

Use one of the various mk(..) constructors to create a new Value.

See Also:

• Property

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	Value.BooleanType
static final class	Value.BooleanValue	A value of type Boolean.
static final class	Value.DateType
static final class	Value.DateValue	A value of type Date.
static final class	Value.LongType
static final class	Value.LongValue	A value of type Long.
static final class	Value.StringType
static final class	Value.StringValue	A value of type String.
static class	Value.TypedValue<A>	Helper type to reduce boilerplate code.
static final class	Value.UntypedType
static class	Value.ValueType<A>	ValueType gives evidence that type A is suitable for the creation of a Value.
static final class	Value.VersionType
static final class	Value.VersionValue	A value of type Version.

Field Summary

Fields

Modifier and Type	Field	Description
static final Value.BooleanType	BOOLEAN
static final Value.DateType	DATE
static final Value.LongType	LONG
static final Value.StringType	STRING
static final Value.UntypedType	UNTYPED
static final Value.VersionType	VERSION

Method Summary

Modifier and Type	Method	Description
final <A> A	decompose(Function<? super String,? extends A> stringValue, Function<? super Date,? extends A> dateValue, Function<? super Long,? extends A> longValue, Function<? super Boolean,? extends A> booleanValue, Function<? super Version,? extends A> versionValue)	Decompose (or pattern match) the value instance.
static <B> Function<Object,B>	doNotMatch()	Use as a placeholder that yields an error in value decomposition.
abstract Object	get()	Get the wrapped value.
final <A> A	get(Value.ValueType<A> ev)	Get the wrapped value in a type safe way.
final Value.ValueType<?>	getType()
static Value.BooleanValue	mk(Boolean value)	Create a new value of type Boolean.
static Value.LongValue	mk(Long value)	Create a new value of type Long.
static Value.StringValue	mk(String value)	Create a new value of type String.
static Value.DateValue	mk(Date value)	Create a new value of type Date.
static <A> Value.TypedValue<A>	mk(Value.ValueType<A> mk, A a)	Generic constructor.
static Value.VersionValue	mk(Version value)	Create a new value of type Version.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

STRING

public static final Value.StringType STRING

DATE

public static final Value.DateType DATE

LONG

public static final Value.LongType LONG

BOOLEAN

public static final Value.BooleanType BOOLEAN

VERSION

public static final Value.VersionType VERSION

UNTYPED

public static final Value.UntypedType UNTYPED

Method Details

get

public abstract Object get()

Get the wrapped value.

get

public final <A> A get(Value.ValueType<A> ev)

Get the wrapped value in a type safe way. Use this method if you are sure about the contained value type. Otherwise consider the use of decompose(Fn, Fn, Fn, Fn, Fn).

Parameters:

ev - Evidence type. The type parameter A of the evidence type must match the type of the wrapped value. Any other value will result in an exception being thrown.

Throws:

RuntimeException - if the passed evidence ev does not match the type of the wrapped value

getType

public final Value.ValueType<?> getType()

decompose

public final <A> A decompose(Function<? super String,? extends A> stringValue,
 Function<? super Date,? extends A> dateValue,
 Function<? super Long,? extends A> longValue,
 Function<? super Boolean,? extends A> booleanValue,
 Function<? super Version,? extends A> versionValue)

Decompose (or pattern match) the value instance. Provide a function to handle each possible type. Use doNotMatch() as a placeholder that yields an error.

doNotMatch

public static <B> Function<Object,B> doNotMatch()

Use as a placeholder that yields an error in value decomposition.

See Also:

• decompose(Fn, Fn, Fn, Fn, Fn)

mk

public static Value.StringValue mk(String value)

Create a new value of type String.

mk

public static Value.DateValue mk(Date value)

Create a new value of type Date.

mk

public static Value.LongValue mk(Long value)

Create a new value of type Long.

mk

public static Value.BooleanValue mk(Boolean value)

Create a new value of type Boolean.

mk

public static Value.VersionValue mk(Version value)

Create a new value of type Version.

mk

public static <A> Value.TypedValue<A> mk(Value.ValueType<A> mk,
 A a)

Generic constructor. Creates a value for any existing ValueType.