ptolemy.data
Class ObjectToken

java.lang.Object
  ptolemy.data.Token
      ptolemy.data.ObjectToken

All Implemented Interfaces:

java.io.Serializable

public class ObjectToken
extends Token

A token that contains a reference to an arbitrary object. Note that when this token constructed, the object passed to the constructor is not cloned. Thus, care must be exercised to ensure that actors do not modify that object in a nondeterministic way, unless such nondeterminism is acceptable.

Since:

Ptolemy II 0.2

Version:

$Id: ObjectToken.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Yellow (wbwu)

Proposed Rating:

Yellow (yuhong)

Field Summary

private java.lang.Class	_class The class of the object.
private java.lang.Object	_value The actual Object.
static ObjectToken	NULL A new empty ObjectToken.

Fields inherited from class ptolemy.data.Token

NIL

Constructor Summary

ObjectToken()
Construct an empty token.

ObjectToken(java.lang.Object value)
Construct a token with a reference to the specified object.

ObjectToken(java.lang.Object value, java.lang.Class<?> valueClass)
Construct a token with the given value and the given class as the value's type.

Method Summary

static ObjectToken	convert(Token token) Convert the specified token into an instance of ObjectToken.
boolean	equals(java.lang.Object object) Return true if the argument is an instance of ObjectToken and its contained object is equal to the object contained in this token, as tested by the equals() method of the contained object.
Type	getType() Return the type of this token.
java.lang.Object	getValue() Return the value of the token, a reference to an object.
java.lang.Class	getValueClass() Return the class of the object contained in this token.
int	hashCode() Return a hash code value for this token.
BooleanToken	isEqualTo(Token rightArgument) Compare this ObjectToken to the given argument, and return true if the values contained in the two are the same Java object.
static ObjectToken	object(java.lang.String className) Return an ObjectToken with value null and class specified by the className argument.
java.lang.String	toString() Return the value of this token as a string that can be parsed by the expression language to recover a token with the same value.

Methods inherited from class ptolemy.data.Token

add, addReverse, divide, divideReverse, isCloseTo, isCloseTo, isNil, modulo, moduloReverse, multiply, multiplyReverse, notSupportedConversionMessage, notSupportedIncomparableConversionMessage, notSupportedIncomparableMessage, notSupportedMessage, notSupportedNullNilStringMessage, one, pow, subtract, subtractReverse, zero, zeroReturnType

Methods inherited from class java.lang.Object

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

Field Detail

NULL

public static final ObjectToken NULL

A new empty ObjectToken.

_class

private java.lang.Class _class

The class of the object.

_value

private java.lang.Object _value

The actual Object. This is protected to allow access in derived classes only.

Constructor Detail

ObjectToken

public ObjectToken()

Construct an empty token.

ObjectToken

public ObjectToken(java.lang.Object value)
            throws IllegalActionException

Construct a token with a reference to the specified object.

Parameters:

value - The specified object referred to by this token.

Throws:

IllegalActionException - If the argument is not of the appropriate type (may be thrown by derived classes, but is not thrown here).

ObjectToken

public ObjectToken(java.lang.Object value,
                   java.lang.Class<?> valueClass)
            throws IllegalActionException

Construct a token with the given value and the given class as the value's type.

Parameters:

value - The value.

valueClass - The class of the value.

Throws:

IllegalActionException - If the argument is not of the appropriate type.

Method Detail

convert

public static ObjectToken convert(Token token)
                           throws IllegalActionException

Convert the specified token into an instance of ObjectToken. This method does lossless conversion. If the argument is already an instance of ObjectToken, it is returned without any change. Otherwise, if the argument is below ObjectToken in the type hierarchy, it is converted to an instance of ObjectToken or one of the subclasses of ObjectToken and returned. If none of the above condition is met, an exception is thrown.

Parameters:

token - The token to be converted to an ObjectToken.

Returns:

An ObjectToken.

Throws:

IllegalActionException - If the conversion cannot be carried out.

equals

public boolean equals(java.lang.Object object)

Return true if the argument is an instance of ObjectToken and its contained object is equal to the object contained in this token, as tested by the equals() method of the contained object.

Overrides:

equals in class java.lang.Object

Parameters:

object - An instance of Object.

Returns:

True if the argument is an instance of ObjectToken and its contained object is equal to the object contained in this token.

getType

public Type getType()

Return the type of this token.

Overrides:

getType in class Token

Returns:

BaseType.OBJECT

getValue

public java.lang.Object getValue()

Return the value of the token, a reference to an object.

Returns:

The Object in this token.

getValueClass

public java.lang.Class getValueClass()

Return the class of the object contained in this token.

Returns:

The class of the object.

hashCode

public int hashCode()

Return a hash code value for this token. This method returns the hash code of the contained object.

Overrides:

hashCode in class java.lang.Object

Returns:

A hash code value for this token.

isEqualTo

public BooleanToken isEqualTo(Token rightArgument)

Compare this ObjectToken to the given argument, and return true if the values contained in the two are the same Java object.

Overrides:

isEqualTo in class Token

Parameters:

rightArgument - The argument.

Returns:

true if the values are the same Java object, or false otherwise.

object

public static ObjectToken object(java.lang.String className)
                          throws IllegalActionException

Return an ObjectToken with value null and class specified by the className argument.

Parameters:

className - The className.

Returns:

The ObjectToken.

Throws:

IllegalActionException - If the class with className as its name cannot be loaded.

toString

public java.lang.String toString()

Return the value of this token as a string that can be parsed by the expression language to recover a token with the same value. The returned syntax looks like a function call to a one argument method named "object". The argument is the string representation of the contained object, or the string "null" if the object is null. Notice that this syntax is not currently parseable by the expression language.

Overrides:

toString in class Token

Returns:

A String representing the object.