Class PersistentObject

java.lang.Object
   |
   +----PersistentObject

public class PersistentObject

extends Object

attachObjId

The Id of the object that is being loaded from the data server

comCons

containers

Vector that contains the object's parent node

containersInMem

Indicates whether the object's containers are in memory

contents

Vector that contains the contents'

contentsInMem

Indicates whether the object's contents are in memory

contextVector

Vector which holds the context information after a getContext

currentRelativeClass

The name of the current class returned during parsing

dbId

Unique identifier returned by the data server after a Save()

debugFlag

Flag to print out debugging statements

dirty

Flag which may be used to determine whether the object requires updating

isPersistent

Variable indicating whether the object has been saved before

loadVector

netClient

netSocket

numChildren

The number of children (objects that attaches to it) that the object has

numField

numObjField

The number of object fields the object has

objectClassName

The class name of the object which inherits the Persistent Object class.

outStreamString

permission

Access permission of the object (READ_ONLY, READ_WRITE) usage to be determined

successfulTransmit

testNoNet

userId

User Id of the Persistent Object (for network transactions)

version

String indicating the version of the object (release_name.number)

PersistentObject()

Constructor of PersistentObject Should never be called explicitly

attach(PersistentObject)

Adds the Persistent Object to the contents Vector, adds this to the pObj's container Vector Returns PO.OK

closeServer(Socket)

Calls closeConnection to close a remote server connection If testNoNet flag is set, then the close is ignored and operations (load, save, etc.) will be done locally

connect(int, int)

Connect (Objects) Sets up the connection at the data back-end

connectServer()

Calls openConnection to connect to remote server If testNoNet flag is set, then the connection is ignored and operations (load, save, etc.) will be done locally

DEBUG(String)

Debug Prints debugging statements if the debug flag is set to true

deleteMe()

Delete Object Deletes the object at the data back-end

detach(PersistentObject)

Detach User can/should only Detach OctObjects that are not Persistent For detaching already Persistent OctObjects, disconnect should be called so that the information gets transferred back to the data server.

detachFrom(PersistentObject)

Detach the (DirObject) container's content's instance of this object

disconnect(int, int)

Disconnect (Objects) Voids the connections at the data back-end

getClassName()

Returns the Object Class Name

getContext()

Sets the vector of (className, str, id) information from the network data server

getField(int, boolean)

getField(int, char)

getField(int, double)

getField(int, double[])

getField(int, float)

getField(int, int)

getField(int, Object)

getField(int, String)

get the corresponding contents from an internal vector that parsed and stored the values of a network Load

getField(int, Vector)

getMemberInfo(int, int)

Return a MemberInfo object which contains the object class name and object id pair

getObjFields()

Determines how the fields of the objects should be filled after a (network) load To be declared by object developer

initGenContainers()

Load objects that are attached at the next upper level of the current object to the Vector contents Return PO.OK if operation is successful PO.ERROR if not

initGenContents()

Load objects that are attached at the next direct level of the current object to the Vector contents Return PO.OK if operation is successful PO.ERROR if not

instancePolicy(PersistentObject)

Policy that must be followed after instantiating an object

load(int)

Load (from Persistent Storage over the network).

load(String)

Load by a (database backend location) string has to be overloaded by the object developer if such a feature is desired

loadObject(String, int, String)

The actual method call thats being made when a load() is called.

loadVersion(String, int, String)

Load a specific version of the object Return PO.OK if Load is successful, PO.ERROR otherwise.

makeInstance()

Loads and instantiates a "copy" of the object from the data back-end.

netObjSetup(int, int, String)

Network Object setup method that needs to be run before the object can operate as a persistent object over the network

parse(int)

parse This method is responsible for parsing responses from remote network server(s) (see http://www-cad.eecs.berkeley.edu/~mds/oct/protocol.html for details) (called after PO_NetClient.openConnection)

parseArray(StreamTokenizer)

Parses an array (arrangement)

parseContext(StreamTokenizer)

Method that parses stream into (className, str, id) information for DirObjects, stringID = content's 1st identifier for Version Object, stringId = content's version string

parseForWord(StreamTokenizer, String)

Verifies that the token is a word/String Prints out the msg if it is not a string, return null returns the String parsed otherwise

parseNumber(StreamTokenizer, String)

Verifies that the token is a number Prints out the msg if it is not a number, returns false

parseQuery(StreamTokenizer)

Method that parses the query reult for QueryObjects To be overloaded in QueryObject.java

postLoadPolicy(Object)

Post-object-loading policy, such as handling of dirty bits, etc., that the object developer has to overload

postSavePolicy(PersistentObject)

Post-object-saving policy, such as handling of dirty bits, etc., that the object developer has to overload

save()

Save (Object) Encapsulation of the actual call to SaveObject (returns either OK, ERROR or the Object's UniqueID)

saveObject(String, int)

Save Object returns Unique DbId if save is completed ERROR if not

savePolicy(PersistentObject)

Object Saving policy, such as handling of dirty bits, etc., that must/should be done before saving.

send(String)

Sends the specified string to the remote server If testNoNet flag is set, then the message will be outputed to the screen

setDebug(boolean)

Sets the flag for debug statement

setField(int, boolean, int)

setField(int, char, int)

setField(int, double, int)

setField(int, double[], int)

setField(int, float, int)

setField(int, int, int)

setField(int, Object, int)

setField(int, String, int)

Sets the fields in the Vector holding the fields of the object Non-object types are stored in object that matches mostly closely its type.

setField(int, Vector, int)

setObjFields()

Sets up the object's fields into internal data structure.

setPersistent(boolean)

Sets the isPersistent flag which indicates that this object has persistence (has a copy at the data backend) Future operations will then make use of the object's unique id.

setPort(int)

Sets the port for network operations

setServer(String)

Sets the server name for network operations

setTestNoNet(boolean)

Sets the flag for network operation

setType(int, int)

sets the type of each field.

versionSave(int)

Saves the object as a new version of the "basic object"

  protected Vector loadVector

  protected Vector contextVector

Vector which holds the context information after a getContext

  protected static PO_CommandConstructor comCons

  protected static PO_NetClient netClient

  protected Socket netSocket

  public static boolean testNoNet

  protected String outStreamString

  protected boolean successfulTransmit

  protected int numField

  protected int numObjField

The number of object fields the object has

  protected String objectClassName

The class name of the object which inherits the Persistent Object class.

  protected String userId

User Id of the Persistent Object (for network transactions)

  protected int dbId

Unique identifier returned by the data server after a Save()

  protected String version

String indicating the version of the object (release_name.number)

  protected int permission

Access permission of the object (READ_ONLY, READ_WRITE) usage to be determined

  public Vector contents

Vector that contains the contents'

  public Vector containers

Vector that contains the object's parent node

  protected int numChildren

The number of children (objects that attaches to it) that the object has

  protected boolean containersInMem

Indicates whether the object's containers are in memory

  protected boolean contentsInMem

Indicates whether the object's contents are in memory

  protected String currentRelativeClass

The name of the current class returned during parsing

  protected int attachObjId

The Id of the object that is being loaded from the data server

  public boolean isPersistent

Variable indicating whether the object has been saved before

  public boolean dirty

Flag which may be used to determine whether the object requires updating

  public static boolean debugFlag

Flag to print out debugging statements

  public PersistentObject()

Constructor of PersistentObject Should never be called explicitly

  public String getClassName()

Returns the Object Class Name

  protected void setPersistent(boolean flag)

Sets the isPersistent flag which indicates that this object has persistence (has a copy at the data backend) Future operations will then make use of the object's unique id.

  protected void setServer(String server)

Sets the server name for network operations

Parameters:

server - Server name

  public static void setPort(int portNum)

Sets the port for network operations

Parameters:

port - Port Number

  public static void setDebug(boolean flag)

Sets the flag for debug statement

Parameters:

flag - true to turn on debugging false otherwise

  public static void setTestNoNet(boolean flag)

Sets the flag for network operation

Parameters:

flag - true if there are no network operations false otherwise

  protected void netObjSetup(int numFields,
                             int numObjs,
                             String objectClassName)

Network Object setup method that needs to be run before the object can operate as a persistent object over the network

Parameters:

port - Port number of the server

numFields - Number of fields the object has

objectClassName - Name of the class

  protected abstract void setObjFields()

Sets up the object's fields into internal data structure. Calls setField with the respective parameters for different types Needs to be overloaded by the object developer

  protected void setType(int nthField,
                         int type)

sets the type of each field. This is a method the Object designer has to overload.

Parameters:

nthField - The position of the field

type - The type of the field

  protected void setField(int nthField,
                          String stringField,
                          int type)

Sets the fields in the Vector holding the fields of the object Non-object types are stored in object that matches mostly closely its type.

Parameters:

nthField - The position of the field

Second_Argument - Different data types may be used

type - The type of the field

  protected void setField(int nthField,
                          int intField,
                          int type)

  protected void setField(int nthField,
                          double doubleField,
                          int type)

  protected void setField(int nthField,
                          char charField,
                          int type)

  protected void setField(int nthField,
                          boolean boolField,
                          int type)

  protected void setField(int nthField,
                          float floatField,
                          int type)

  protected void setField(int nthField,
                          Vector vectorField,
                          int type)

  protected void setField(int nthField,
                          Object objField,
                          int type)

  protected void setField(int nthField,
                          double arrayField[],
                          int type)

  protected boolean connectServer()

Calls openConnection to connect to remote server If testNoNet flag is set, then the connection is ignored and operations (load, save, etc.) will be done locally

  protected boolean closeServer(Socket socket)

Calls closeConnection to close a remote server connection If testNoNet flag is set, then the close is ignored and operations (load, save, etc.) will be done locally

  protected void send(String msg)

Sends the specified string to the remote server If testNoNet flag is set, then the message will be outputed to the screen

Parameters:

msg - The message/string to be sent

  public int save()

Save (Object) Encapsulation of the actual call to SaveObject (returns either OK, ERROR or the Object's UniqueID)

  public int versionSave(int versionFlag)

Saves the object as a new version of the "basic object"

Parameters:

versionFlag - Indicator of whether a "point" (single object) is to be saved or the whole "tree", rooted at this point

  protected int saveObject(String objectClassName,
                           int versionFlag)

Save Object returns Unique DbId if save is completed ERROR if not

Parameters:

objectClassName - Name of the class

  public boolean load(int intId)

Load (from Persistent Storage over the network). Return PO.OK if Load is successful, PO.ERROR otherwise.

Parameters:

strId - String type of id

intId - Integer type of id

  public boolean load(String strId)

Load by a (database backend location) string has to be overloaded by the object developer if such a feature is desired

  public boolean loadVersion(String strId,
                             int intId,
                             String version)

Load a specific version of the object Return PO.OK if Load is successful, PO.ERROR otherwise.

Parameters:

strId - String type of id

intId - Integer type of id

version - Version of the object

  protected abstract void getObjFields()

Determines how the fields of the objects should be filled after a (network) load To be declared by object developer

  protected boolean loadObject(String strId,
                               int intId,
                               String version)

The actual method call thats being made when a load() is called.

Parameters:

objectClassName - (String) Name of the class

strId - String type of Id of the object

intId - Integer type of Id of the object

version - Version of the object

  protected PersistentObject makeInstance()

Loads and instantiates a "copy" of the object from the data back-end.

  public void instancePolicy(PersistentObject pObj)

Policy that must be followed after instantiating an object

  protected String getField(int nthField,
                            String indicator)

get the corresponding contents from an internal vector that parsed and stored the values of a network Load

Parameters:

nthField - Position of the field

Indictor - Different types according to the type expected

  protected int getField(int nthField,
                         int indicator)

  protected double getField(int nthField,
                            double indicator)

  protected boolean getField(int nthField,
                             boolean indicator)

  protected char getField(int nthField,
                          char indicator)

  protected float getField(int nthField,
                           float indicator)

  protected double[] getField(int nthField,
                              double indicator[])

  protected Vector getField(int nthField,
                            Vector indicator)

  protected PersistentObject getField(int nthField,
                                      Object indicator)

  protected Vector parse(int preceedingOp)

parse This method is responsible for parsing responses from remote network server(s) (see http://www-cad.eecs.berkeley.edu/~mds/oct/protocol.html for details) (called after PO_NetClient.openConnection)

  protected boolean parseNumber(StreamTokenizer strToke,
                                String msg)

Verifies that the token is a number Prints out the msg if it is not a number, returns false

Parameters:

strToke - StreamTokenizer to be verified

msg - Error message to be outputed

  protected double[] parseArray(StreamTokenizer strToke)

Parses an array (arrangement)

  protected String parseForWord(StreamTokenizer strToke,
                                String msg)

Verifies that the token is a word/String Prints out the msg if it is not a string, return null returns the String parsed otherwise

Parameters:

strToke - StreamTokenizer to be verified

msg - Error message to be outputed

  protected Vector parseContext(StreamTokenizer strToke)

Method that parses stream into (className, str, id) information for DirObjects, stringID = content's 1st identifier for Version Object, stringId = content's version string

  protected Vector parseQuery(StreamTokenizer strToke)

Method that parses the query reult for QueryObjects To be overloaded in QueryObject.java

  public Vector getContext()

Sets the vector of (className, str, id) information from the network data server

  protected int connect(int parentId,
                        int childId)

Connect (Objects) Sets up the connection at the data back-end

Parameters:

parentId - Id of the parent

childId - Id of the child

  protected int disconnect(int parentId,
                           int childId)

Disconnect (Objects) Voids the connections at the data back-end

Parameters:

parentId - Id of the parent

childId - Id of the child

  public int attach(PersistentObject pObj)

Adds the Persistent Object to the contents Vector, adds this to the pObj's container Vector Returns PO.OK

Parameters:

pObj - PersistentObject to be added

  public int detach(PersistentObject pObj)

Detach User can/should only Detach OctObjects that are not Persistent For detaching already Persistent OctObjects, disconnect should be called so that the information gets transferred back to the data server.

Parameters:

obj - object to Detach

  public void detachFrom(PersistentObject cnt)

Detach the (DirObject) container's content's instance of this object

Parameters:

cnt - The container to delete from

  protected int deleteMe()

Delete Object Deletes the object at the data back-end

  protected int savePolicy(PersistentObject pObj)

Object Saving policy, such as handling of dirty bits, etc., that must/should be done before saving. The object developer has to overload this method.

Parameters:

obj - Object to be saved

  protected void postSavePolicy(PersistentObject pObj)

Post-object-saving policy, such as handling of dirty bits, etc., that the object developer has to overload

Parameters:

obj - Object that has been saved

  protected void postLoadPolicy(Object obj)

Post-object-loading policy, such as handling of dirty bits, etc., that the object developer has to overload

Parameters:

Object - that has been loaded

  public int initGenContents()

Load objects that are attached at the next direct level of the current object to the Vector contents Return PO.OK if operation is successful PO.ERROR if not

  public int initGenContainers()

Load objects that are attached at the next upper level of the current object to the Vector contents Return PO.OK if operation is successful PO.ERROR if not

  protected PersistentObject getMemberInfo(int type,
                                           int index)

Return a MemberInfo object which contains the object class name and object id pair

Parameters:

type - Either PARENTS or CHILDREN

index - The position of the object field

  protected void DEBUG(String debugStmt)

Debug Prints debugging statements if the debug flag is set to true

Parameters:

debugStmt - The debugging statement supplied