org.vrspace.server
Class VRObject

java.lang.Object
  java.util.Observable
      org.vrspace.server.VRObject

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

DBObject, PassiveVRObject, PrivateVRObject, PublicVRObject

public class VRObject

extends java.util.Observable

implements java.lang.Cloneable

Generic VRObject class.
Defines event forwarding, does not check nor set actual field value.
Subclasses should override setValue() method to implement different behavior, i.e. store object to database and/or forward events.

NOTES:
- set_* (see setField()) method may access both Client and Dispatcher via Request
- before invoking set_*, request may forwarded to all the Observers, depending on sendEvent()/setValue() implementation
- along with request, other Clients (Observers) get reference to originating Client - TAKE CARE of public variables !!!
- this way, clients may send requests (Client.update()) to each other without Dispatcher interference - usefull for chat, smart server-side classes etc.
- it's up to each client to check the request origin and perform other actions
- if set_ method is invoked before forwarding, it may cancel forwarding by calling clearChanged(), depending on sendEvent()/setValue() implementation
- in general, sendEvent() should invoke setChanged() or generate VRObjectException, setValue() should invoke notifyObservers( Request ), and somewhere between those field is set and clearChanged() is eventualy called

Field Summary

long	db_id
static java.util.HashMap	primitiveMap
static java.util.HashMap	primitives

Constructor Summary

VRObject()

Method Summary

static java.lang.String	arrayToString(java.lang.Object array) Converts array val to String.
boolean	canRead(java.lang.String name) Returns true if there's either field or get_ method
boolean	canWrite(java.lang.String name) Returns true if there's either field or set_ method
java.lang.Object	clone()
boolean	equals(VRObject obj) VRObject.equals( VRObject ) if class and db_id are the same
java.lang.String	fieldToText(java.lang.reflect.Field field)
int	fromString(java.lang.String s) Uses toString() formated String to set variables
static VRObject[]	fromText(java.lang.String definition) Returns array of objects defined by string in toText() format
java.lang.String	getClassName() Returns class name without package name.
java.lang.Object	getField(java.lang.String name) Returns a field value.
java.lang.String[]	getFields() Returns names of all public member varaibles.
long	getId() Returns objects unique id
ID	getID() Returns objects unique id
VRObject[]	getMemebers() Returns VRObjects that are member variables of this object.
boolean	hasField(java.lang.String name) Returns true if this object contains public field with this name
boolean	hasMethod(java.lang.String name) Returns true if this object contains public method with this name
boolean	isNew() new object?
static VRObject	newInstance(java.lang.String className) Creates new instance of className.
void	sendEvent(Request r) Forwards request r to other clients, Observers added by Dispatcher.
boolean	sendResponse() send OK on successfull execution?
void	setField(Request r) Sets field r.getEventName() to r.getEventValue()
void	setField(java.lang.String name, java.lang.String value) Sets field name to value
void	setField(java.lang.String name, java.lang.String value, Request r) Equals to obj.name = value.
void	setFields(java.lang.String[] names, java.lang.String args) setFields() on all variables specified in parse args and set each
void	setFields(VRObject o) Takes field values from passed object, by field name.
protected void	setValue(Request r) This implementation does nothing
static java.lang.Object	stringToArray(java.lang.Class cl, java.lang.String val) Converts String in arrayToString() format back to array.
java.lang.String	toString() Converts VRObject to String.
java.lang.String	toText() Returns string representation of objects, used by fromText()
static java.lang.String	toText(java.lang.Object[] obj) Returns string representation of objects, used by fromText()
java.lang.String	toText(java.lang.String filter) As toText(), but does not return fields beginning with filter.

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Field Detail

db_id

public long db_id

primitives

public static final java.util.HashMap primitives

primitiveMap

public static final java.util.HashMap primitiveMap

Constructor Detail

VRObject

public VRObject()

Method Detail

isNew

public boolean isNew()

new object?

sendResponse

public boolean sendResponse()

send OK on successfull execution?

getId

public long getId()

Returns objects unique id

getID

public ID getID()

Returns objects unique id

fromString

public int fromString(java.lang.String s)
               throws VRObjectException,
                      java.lang.NoSuchFieldException,
                      java.lang.ClassNotFoundException,
                      java.lang.IllegalAccessException,
                      java.lang.InstantiationException,
                      java.lang.NoSuchMethodException,
                      java.lang.reflect.InvocationTargetException

Uses toString() formated String to set variables

Throws:

VRObjectException

java.lang.NoSuchFieldException

java.lang.ClassNotFoundException

java.lang.IllegalAccessException

java.lang.InstantiationException

java.lang.NoSuchMethodException

java.lang.reflect.InvocationTargetException

toString

public java.lang.String toString()

Converts VRObject to String. BUG: quotes inside string

arrayToString

public static java.lang.String arrayToString(java.lang.Object array)

Converts array val to String.

stringToArray

public static java.lang.Object stringToArray(java.lang.Class cl,
                                             java.lang.String val)

Converts String in arrayToString() format back to array.

toText

public static java.lang.String toText(java.lang.Object[] obj)
                               throws java.lang.IllegalAccessException

Returns string representation of objects, used by fromText()

Throws:

java.lang.IllegalAccessException

toText

public java.lang.String toText()
                        throws java.lang.IllegalAccessException

Returns string representation of objects, used by fromText()

Throws:

java.lang.IllegalAccessException

fieldToText

public java.lang.String fieldToText(java.lang.reflect.Field field)
                             throws java.lang.IllegalAccessException

Throws:

java.lang.IllegalAccessException

toText

public java.lang.String toText(java.lang.String filter)
                        throws java.lang.IllegalAccessException

As toText(), but does not return fields beginning with filter. Used for sending events over the network.

Throws:

java.lang.IllegalAccessException

getClassName

public java.lang.String getClassName()

Returns class name without package name.

fromText

public static VRObject[] fromText(java.lang.String definition)
                           throws java.lang.NoSuchMethodException,
                                  java.lang.NoSuchFieldException,
                                  java.lang.IllegalAccessException,
                                  java.lang.InstantiationException,
                                  java.lang.ClassNotFoundException,
                                  java.lang.reflect.InvocationTargetException,
                                  VRObjectException,
                                  java.lang.Exception

Returns array of objects defined by string in toText() format

Throws:

java.lang.NoSuchMethodException

java.lang.NoSuchFieldException

java.lang.IllegalAccessException

java.lang.InstantiationException

java.lang.ClassNotFoundException

java.lang.reflect.InvocationTargetException

VRObjectException

java.lang.Exception

newInstance

public static VRObject newInstance(java.lang.String className)

Creates new instance of className. May return null if instantiation fails,

setFields

public void setFields(java.lang.String[] names,
                      java.lang.String args)
               throws VRObjectException

setFields() on all variables specified in parse args and set each

Throws:

VRObjectException

setFields

public void setFields(VRObject o)

Takes field values from passed object, by field name. Non-exisisting fields ignored.

setField

public void setField(java.lang.String name,
                     java.lang.String value)
              throws VRObjectException

Sets field name to value

Throws:

VRObjectException

setField

public void setField(Request r)
              throws VRObjectException

Sets field r.getEventName() to r.getEventValue()

Throws:

VRObjectException

See Also:

Request

setField

public void setField(java.lang.String name,
                     java.lang.String value,
                     Request r)
              throws VRObjectException

Equals to obj.name = value. If this raises exception, tries obj.set_name( Request r, String value )

Throws:

VRObjectException

sendEvent

public void sendEvent(Request r)
               throws RequestException

Forwards request r to other clients, Observers added by Dispatcher. Throws RequestException if request target is another object. Calls setValue() method which actualy forwards the event. NOTE: All the Observers (Clients!) have access to VRObject - TAKE CARE of public variables (reading) and public methodes (generating events)

Throws:

RequestException

setValue

protected void setValue(Request r)

This implementation does nothing

getMemebers

public VRObject[] getMemebers()

Returns VRObjects that are member variables of this object.

getFields

public java.lang.String[] getFields()

Returns names of all public member varaibles. Use getField( String ) to retreive value.

See Also:

getField(java.lang.String)

hasField

public boolean hasField(java.lang.String name)

Returns true if this object contains public field with this name

hasMethod

public boolean hasMethod(java.lang.String name)

Returns true if this object contains public method with this name

canWrite

public boolean canWrite(java.lang.String name)

Returns true if there's either field or set_ method

canRead

public boolean canRead(java.lang.String name)

Returns true if there's either field or get_ method

getField

public java.lang.Object getField(java.lang.String name)
                          throws VRObjectException

Returns a field value. If there's no member with this name, tries to execute "get_"+name method.

Throws:

VRObjectException - if neither field nor method were found

equals

public boolean equals(VRObject obj)

VRObject.equals( VRObject ) if class and db_id are the same

clone

public java.lang.Object clone()