uk.ac.starlink.plastic
Class ValueType

java.lang.Object
  uk.ac.starlink.plastic.ValueType

public class ValueType

extends Object

Defines the type of a value which is passed through the PLASTIC messaging system. These types define what is legal for the arguments and return values of each particular message. The types defined are ones which can be transmitted and have the same meaning using both the Java RMI and the XML-RPC transport modes.

Since:

19 Jul 2006

Author:

Mark Taylor

See Also:

MessageDefinition

Field Summary

static ValueType	ANY No constraints - any object is permissible.
static ValueType	BOOLEAN Boolean type.
static ValueType	DATE ISO-8601 date type.
static ValueType	DOUBLE Double precision type.
static ValueType	INT Integer type.
static ValueType	LIST List/<array> type.
static ValueType	LIST_INTS List/ type in which all elements must be integers.
static ValueType	MAP Map/<struct> type.
static ValueType	STRING String type.
static ValueType	STRING_IVORN Type for a string which is required to be a legal IVORN.
static ValueType	STRING_URI Type for a string which is required to be a legal URI.
static ValueType	STRING_URL Type for a string which is required to be a legal URL.
static ValueType	VOID Void type - the return type for methods with no return value.

Constructor Summary

ValueType(String name, Class jClazz, Object blank)
Constructs a basic value type with a given symbolic name and a java class which all legal values of this type must instantiate.

Method Summary

void	checkJavaValue(Object jValue) Checks a value sent or received using Java-RMI.
Object	getBlankValue() Returns a neutral sort of value which is legal for this type.
static ValueType	inferValueType(Object value) Guesses from a single value what type it might correspond to.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

ANY

public static ValueType ANY

No constraints - any object is permissible.

INT

public static ValueType INT

Integer type.

BOOLEAN

public static ValueType BOOLEAN

Boolean type.

STRING

public static ValueType STRING

String type.

DOUBLE

public static ValueType DOUBLE

Double precision type.

DATE

public static ValueType DATE

ISO-8601 date type.

MAP

public static ValueType MAP

Map/<struct> type.

LIST

public static ValueType LIST

List/<array> type.

VOID

public static ValueType VOID

Void type - the return type for methods with no return value.

STRING_URL

public static ValueType STRING_URL

Type for a string which is required to be a legal URL.

STRING_IVORN

public static ValueType STRING_IVORN

Type for a string which is required to be a legal IVORN.

STRING_URI

public static ValueType STRING_URI

Type for a string which is required to be a legal URI.

LIST_INTS

public static ValueType LIST_INTS

List/ type in which all elements must be integers.

Constructor Detail

ValueType

public ValueType(String name,
                 Class jClazz,
                 Object blank)

Constructs a basic value type with a given symbolic name and a java class which all legal values of this type must instantiate.

Parameters:

name - label for this type (for documentation purposes only)

jClazz - required assignable java class

blank - suitable blank value (see getBlankValue())

Method Detail

checkJavaValue

public void checkJavaValue(Object jValue)
                    throws ValueTypeException

Checks a value sent or received using Java-RMI. If the value has a type which is inconsistent with the constraints defined by this object, a ValueTypeException will be thrown.

Parameters:

jValue - value to check

Throws:

ValueTypeException

getBlankValue

public Object getBlankValue()

Returns a neutral sort of value which is legal for this type. This is not guaranteed to be suitable for any given use, but if you have to come up with a value for this type and don't have any other information, it's as good a guess as any.

Returns:

blank value compatible with this type

toString

public String toString()

inferValueType

public static ValueType inferValueType(Object value)
                                throws ValueTypeException

Guesses from a single value what type it might correspond to. Necessarily unreliable.

Parameters:

value - example value

Returns:

ValueType that value might be an instance of

Throws:

ValueTypeException