org.mozilla.javascript

Class NativeJavaObject

java.lang.Object

org.mozilla.javascript.NativeJavaObject

All Implemented Interfaces:

java.io.Serializable, Scriptable, Wrapper

Direct Known Subclasses:

NativeJavaArray, NativeJavaClass

public class NativeJavaObject
extends java.lang.Object
implements Scriptable, Wrapper, java.io.Serializable

This class reflects non-Array Java objects into the JavaScript environment. It reflect fields directly, and uses NativeJavaMethod objects to reflect (possibly overloaded) methods.

Author:

Mike Shaver

See Also:

NativeJavaArray, NativeJavaPackage, NativeJavaClass, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	isAdapter
protected java.lang.Object	javaObject
protected org.mozilla.javascript.JavaMembers	members
protected Scriptable	parent The parent scope of this object.
protected Scriptable	prototype The prototype of this object.
protected java.lang.Class<?>	staticType

Fields inherited from interface org.mozilla.javascript.Scriptable

NOT_FOUND

Constructor Summary

Constructors

Constructor and Description
NativeJavaObject()
NativeJavaObject(Scriptable scope, java.lang.Object javaObject, java.lang.Class<?> staticType)
NativeJavaObject(Scriptable scope, java.lang.Object javaObject, java.lang.Class<?> staticType, boolean isAdapter)

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	canConvert(java.lang.Object fromObj, java.lang.Class<?> to) Determine whether we can/should convert between the given type and the desired one.
static java.lang.Object	coerceType(java.lang.Class<?> type, java.lang.Object value) Deprecated. as of 1.5 Release 4
protected static java.lang.Object	createInterfaceAdapter(java.lang.Class<?> type, ScriptableObject so)
void	delete(int index) Removes a property from this object.
void	delete(java.lang.String name) Removes a property from this object.
java.lang.Object	get(int index, Scriptable start) Get a property from the object selected by an integral index.
java.lang.Object	get(java.lang.String name, Scriptable start) Get a named property from the object.
java.lang.String	getClassName() Get the name of the set of objects implemented by this Java class.
java.lang.Object	getDefaultValue(java.lang.Class<?> hint) Get the default value of the object with a given hint.
java.lang.Object[]	getIds() Get an array of property ids.
Scriptable	getParentScope() Returns the parent (enclosing) scope of the object.
Scriptable	getPrototype() Get the prototype of the object.
boolean	has(int index, Scriptable start) Indicates whether or not an indexed property is defined in an object.
boolean	has(java.lang.String name, Scriptable start) Indicates whether or not a named property is defined in an object.
boolean	hasInstance(Scriptable value) The instanceof operator.
protected void	initMembers()
void	put(int index, Scriptable start, java.lang.Object value) Sets an indexed property in this object.
void	put(java.lang.String name, Scriptable start, java.lang.Object value) Sets a named property in this object.
void	setParentScope(Scriptable m) Sets the parent (enclosing) scope of the object.
void	setPrototype(Scriptable m) Sets the prototype of the object.
java.lang.Object	unwrap() Unwrap the object by returning the wrapped value.
static java.lang.Object	wrap(Scriptable scope, java.lang.Object obj, java.lang.Class<?> staticType) Deprecated. Use Context.getWrapFactory() together with calling WrapFactory.wrap(Context, Scriptable, Object, Class)

Methods inherited from class java.lang.Object

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

Field Detail

prototype

protected Scriptable prototype

The prototype of this object.

parent

protected Scriptable parent

The parent scope of this object.

javaObject

protected transient java.lang.Object javaObject

staticType

protected transient java.lang.Class<?> staticType

members

protected transient org.mozilla.javascript.JavaMembers members

isAdapter

protected transient boolean isAdapter

Constructor Detail

NativeJavaObject

public NativeJavaObject()

NativeJavaObject

public NativeJavaObject(Scriptable scope,
                java.lang.Object javaObject,
                java.lang.Class<?> staticType)

NativeJavaObject

public NativeJavaObject(Scriptable scope,
                java.lang.Object javaObject,
                java.lang.Class<?> staticType,
                boolean isAdapter)

Method Detail

initMembers

protected void initMembers()

has

public boolean has(java.lang.String name,
          Scriptable start)

Description copied from interface: Scriptable

Indicates whether or not a named property is defined in an object. Does not traverse the prototype chain.

The property is specified by a String name as defined for the get method.

Specified by:

has in interface Scriptable

Parameters:

name - the name of the property

start - the object in which the lookup began

Returns:

true if and only if the named property is found in the object

See Also:

Scriptable.get(String, Scriptable), ScriptableObject.getProperty(Scriptable, String)

has

public boolean has(int index,
          Scriptable start)

Description copied from interface: Scriptable

Indicates whether or not an indexed property is defined in an object. Does not traverse the prototype chain.

The property is specified by an integral index as defined for the get method.

Specified by:

has in interface Scriptable

Parameters:

index - the numeric index for the property

start - the object in which the lookup began

Returns:

true if and only if the indexed property is found in the object

See Also:

Scriptable.get(int, Scriptable), ScriptableObject.getProperty(Scriptable, int)

get

public java.lang.Object get(java.lang.String name,
                   Scriptable start)

Description copied from interface: Scriptable

Get a named property from the object. Looks property up in this object and returns the associated value if found. Returns NOT_FOUND if not found. Note that this method is not expected to traverse the prototype chain. This is different from the ECMA [[Get]] operation. Depending on the property selector, the runtime will call this method or the form of get that takes an integer:

JavaScript code	Java code
a.b	a.get("b", a)
a["foo"]	a.get("foo", a)
a[3]	a.get(3, a)
a["3"]	a.get(3, a)
a[3.0]	a.get(3, a)
a["3.0"]	a.get("3.0", a)
a[1.1]	a.get("1.1", a)
a[-4]	a.get(-4, a)

The values that may be returned are limited to the following:

• java.lang.Boolean objects
• java.lang.String objects
• java.lang.Number objects
• org.mozilla.javascript.Scriptable objects
• null
• The value returned by Context.getUndefinedValue()
• NOT_FOUND

Specified by:

get in interface Scriptable

Parameters:

name - the name of the property

start - the object in which the lookup began

Returns:

the value of the property (may be null), or NOT_FOUND

See Also:

Context.getUndefinedValue()

get

public java.lang.Object get(int index,
                   Scriptable start)

Description copied from interface: Scriptable

Get a property from the object selected by an integral index. Identical to get(String, Scriptable) except that an integral index is used to select the property.

Specified by:

get in interface Scriptable

Parameters:

index - the numeric index for the property

start - the object in which the lookup began

Returns:

the value of the property (may be null), or NOT_FOUND

See Also:

Scriptable.get(String,Scriptable)

put

public void put(java.lang.String name,
       Scriptable start,
       java.lang.Object value)

Description copied from interface: Scriptable

Sets a named property in this object.

The property is specified by a string name as defined for get.

The possible values that may be passed in are as defined for get. A class that implements this method may choose to ignore calls to set certain properties, in which case those properties are effectively read-only.

For properties defined in a prototype chain, use putProperty in ScriptableObject.

Note that if a property a is defined in the prototype p of an object o, then evaluating o.a = 23 will cause set to be called on the prototype p with o as the start parameter. To preserve JavaScript semantics, it is the Scriptable object's responsibility to modify o.

This design allows properties to be defined in prototypes and implemented in terms of getters and setters of Java values without consuming slots in each instance.

The values that may be set are limited to the following:

• java.lang.Boolean objects
• java.lang.String objects
• java.lang.Number objects
• org.mozilla.javascript.Scriptable objects
• null
• The value returned by Context.getUndefinedValue()

Arbitrary Java objects may be wrapped in a Scriptable by first calling Context.toObject. This allows the property of a JavaScript object to contain an arbitrary Java object as a value.

Note that has will be called by the runtime first before set is called to determine in which object the property is defined. Note that this method is not expected to traverse the prototype chain, which is different from the ECMA [[Put]] operation.

Specified by:

put in interface Scriptable

Parameters:

name - the name of the property

start - the object whose property is being set

value - value to set the property to

See Also:

Scriptable.has(String, Scriptable), Scriptable.get(String, Scriptable), ScriptableObject.putProperty(Scriptable, String, Object), Context.toObject(Object, Scriptable)

put

public void put(int index,
       Scriptable start,
       java.lang.Object value)

Description copied from interface: Scriptable

Sets an indexed property in this object.

The property is specified by an integral index as defined for get.

Identical to put(String, Scriptable, Object) except that an integral index is used to select the property.

Specified by:

put in interface Scriptable

Parameters:

index - the numeric index for the property

start - the object whose property is being set

value - value to set the property to

See Also:

Scriptable.has(int, Scriptable), Scriptable.get(int, Scriptable), ScriptableObject.putProperty(Scriptable, int, Object), Context.toObject(Object, Scriptable)

hasInstance

public boolean hasInstance(Scriptable value)

Description copied from interface: Scriptable

The instanceof operator.

The JavaScript code "lhs instanceof rhs" causes rhs.hasInstance(lhs) to be called.

The return value is implementation dependent so that embedded host objects can return an appropriate value. See the JS 1.3 language documentation for more detail.

This operator corresponds to the proposed EMCA [[HasInstance]] operator.

Specified by:

hasInstance in interface Scriptable

Parameters:

value - The value that appeared on the LHS of the instanceof operator

Returns:

an implementation dependent value

delete

public void delete(java.lang.String name)

Description copied from interface: Scriptable

Removes a property from this object. This operation corresponds to the ECMA [[Delete]] except that the no result is returned. The runtime will guarantee that this method is called only if the property exists. After this method is called, the runtime will call Scriptable.has to see if the property has been removed in order to determine the boolean result of the delete operator as defined by ECMA 11.4.1.

A property can be made permanent by ignoring calls to remove it.

The property is specified by a String name as defined for get.

To delete properties defined in a prototype chain, see deleteProperty in ScriptableObject.

Specified by:

delete in interface Scriptable

Parameters:

name - the identifier for the property

See Also:

Scriptable.get(String, Scriptable), ScriptableObject.deleteProperty(Scriptable, String)

delete

public void delete(int index)

Description copied from interface: Scriptable

Removes a property from this object. The property is specified by an integral index as defined for get.

To delete properties defined in a prototype chain, see deleteProperty in ScriptableObject. Identical to delete(String) except that an integral index is used to select the property.

Specified by:

delete in interface Scriptable

Parameters:

index - the numeric index for the property

See Also:

Scriptable.get(int, Scriptable), ScriptableObject.deleteProperty(Scriptable, int)

getPrototype

public Scriptable getPrototype()

Description copied from interface: Scriptable

Get the prototype of the object.

Specified by:

getPrototype in interface Scriptable

Returns:

the prototype

setPrototype

public void setPrototype(Scriptable m)

Sets the prototype of the object.

Specified by:

setPrototype in interface Scriptable

Parameters:

m - the prototype to set

getParentScope

public Scriptable getParentScope()

Returns the parent (enclosing) scope of the object.

Specified by:

getParentScope in interface Scriptable

Returns:

the parent scope

setParentScope

public void setParentScope(Scriptable m)

Sets the parent (enclosing) scope of the object.

Specified by:

setParentScope in interface Scriptable

Parameters:

m - the parent scope to set

getIds

public java.lang.Object[] getIds()

Description copied from interface: Scriptable

Get an array of property ids. Not all property ids need be returned. Those properties whose ids are not returned are considered non-enumerable.

Specified by:

getIds in interface Scriptable

Returns:

an array of Objects. Each entry in the array is either a java.lang.String or a java.lang.Number

wrap

public static java.lang.Object wrap(Scriptable scope,
                    java.lang.Object obj,
                    java.lang.Class<?> staticType)

Deprecated. Use Context.getWrapFactory() together with calling WrapFactory.wrap(Context, Scriptable, Object, Class)

unwrap

public java.lang.Object unwrap()

Description copied from interface: Wrapper

Unwrap the object by returning the wrapped value.

Specified by:

unwrap in interface Wrapper

Returns:

a wrapped value

getClassName

public java.lang.String getClassName()

Description copied from interface: Scriptable

Get the name of the set of objects implemented by this Java class. This corresponds to the [[Class]] operation in ECMA and is used by Object.prototype.toString() in ECMA.

See ECMA 8.6.2 and 15.2.4.2.

Specified by:

getClassName in interface Scriptable

getDefaultValue

public java.lang.Object getDefaultValue(java.lang.Class<?> hint)

Description copied from interface: Scriptable

Get the default value of the object with a given hint. The hints are String.class for type String, Number.class for type Number, Scriptable.class for type Object, and Boolean.class for type Boolean.

A hint of null means "no hint". See ECMA 8.6.2.6.

Specified by:

getDefaultValue in interface Scriptable

Parameters:

hint - the type hint

Returns:

the default value

canConvert

public static boolean canConvert(java.lang.Object fromObj,
                 java.lang.Class<?> to)

Determine whether we can/should convert between the given type and the desired one. This should be superceded by a conversion-cost calculation function, but for now I'll hide behind precedent.

coerceType

public static java.lang.Object coerceType(java.lang.Class<?> type,
                          java.lang.Object value)

Deprecated. as of 1.5 Release 4

Not intended for public use. Callers should use the public API Context.toType.

See Also:

Context.jsToJava(Object, Class)

createInterfaceAdapter

protected static java.lang.Object createInterfaceAdapter(java.lang.Class<?> type,
                                      ScriptableObject so)