org.w3c.tools.resources
Class AttributeHolder

java.lang.Object
  |
  +--org.w3c.tools.resources.AttributeHolder
Direct Known Subclasses:
PutedEntry, PutedEntry, Resource, ResourceStoreState

public class AttributeHolder
extends java.lang.Object
implements java.lang.Cloneable

An attribute holder is an object that holds a list of attributes. Each of the attributes maintained by a holder are described by an Attribute object, wich is able to pickle/unpickle its value, provides the status of the attribute (eg mandatory, editable, etc), etc.

Given this, an attribute holder is able to pickle its state (made of its attribute values), and unpickle it to any DataOutputStream (resp. DataInputStream).

See Also:
Attribute, Resource

Field Summary
protected  Attribute[] attributes
          Pointer to this class registered list of attributes.
protected  boolean slowpickle
          Turns on/off fast pickling.
protected  java.lang.Object[] values
          Attribute values.
 
Constructor Summary
AttributeHolder()
          Create an attribute holder.
 
Method Summary
 boolean definesAttribute(int idx)
          Does this resource has defined a value for the given attribute.
 boolean definesAttribute(java.lang.String name)
          Does this resource has defined a value for the given attribute.
 Attribute[] getAttributes()
          Get this attribute holders attributes description.
 boolean getBoolean(int idx, boolean def)
           
 char getChar(int idx, char def)
           
 java.lang.Object getClone()
          Clone this attribute holder.
 java.lang.Object getClone(java.util.Hashtable defs)
          Clone this AttributeHolder instance, and initialize it with defaults.
 java.lang.Object getClone(java.lang.Object[] values)
          Clone this attribute holder, and init it with the given attributes.
 double getDouble(int idx, double def)
           
 float getFloat(int idx, float def)
           
 int getInt(int idx, int def)
           
 long getLong(int idx, long def)
           
 java.lang.String getString(int idx, java.lang.String def)
           
 java.lang.Object getValue(int idx, java.lang.Object def)
          Generic get of an attribute value.
 java.lang.Object getValue(java.lang.String name, java.lang.Object def)
          Generic get of an attribute value.
 void initialize(java.util.Hashtable defs)
          Initialization method for attribute holders.
 void initialize(java.lang.Object[] values)
          Initialization method for attribute holders.
 int lookupAttribute(java.lang.String name)
          Lookup up the index of an attribute in our attribute description.
 void pickle(java.io.DataOutputStream out)
          Pickle this attribute holder to the given stream.
 void print(java.io.PrintStream out)
          Debugging purposes only, print this attribute holder.
 void setBoolean(int idx, boolean b)
           
 void setChar(int idx, char ch)
           
 void setDouble(int idx, double d)
           
 void setFloat(int idx, float f)
           
 void setInt(int idx, int i)
           
 void setLong(int idx, long l)
           
 void setString(int idx, java.lang.String s)
           
 void setValue(int idx, java.lang.Object value)
          Set an attribute value.
 void setValue(java.lang.String name, java.lang.Object value)
          Set an attribute value.
static AttributeHolder unpickle(java.io.DataInputStream in)
          Unpickle an attribute holder from the given input stream.
static AttributeHolder unpickle(java.io.DataInputStream in, java.util.Hashtable defs)
          A short hand for unpickling and initializing a resource.
static AttributeHolder unpickle(java.io.DataInputStream in, java.util.Hashtable defs, boolean init)
          Unpickle an attribute holder from the given input stream.
 AttributeHolder unpickleInstance(java.io.DataInputStream in, java.util.Hashtable defs)
          A short-hand for unpickling and initializing resources.
 AttributeHolder unpickleInstance(java.io.DataInputStream in, java.util.Hashtable defs, boolean init)
          Finish the instance part of the unpickling job.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

slowpickle

protected boolean slowpickle
Turns on/off fast pickling.

Fast pickling is a mode of pickling attribute holders in which evolutivity is lost in favor of speed. With slow pickling obtained by setting that flag to false, resources are dumped in a alist like format, so you can preserve informations if the attribute list changes.


attributes

protected Attribute[] attributes
Pointer to this class registered list of attributes.

values

protected java.lang.Object[] values
Attribute values.
Constructor Detail

AttributeHolder

public AttributeHolder()
Create an attribute holder.
Method Detail

getClone

public java.lang.Object getClone(java.lang.Object[] values)
Clone this attribute holder, and init it with the given attributes.
Parameters:
values - Attribute values to overide in the clone.
Returns:
A clone of this resource.

getClone

public java.lang.Object getClone()
Clone this attribute holder. The resulting clone will share the attribute values of the cloned attribute holder.
Returns:
An attribute holder sharing its ancestor attribute values.

getClone

public java.lang.Object getClone(java.util.Hashtable defs)
Clone this AttributeHolder instance, and initialize it with defaults. This method first clones the receiving attribute holder, and then uses the defaults provided to finish the initialization.
Parameters:
defs - The attribute values, in a Hashtable.
Returns:
The clone.

getAttributes

public Attribute[] getAttributes()
Get this attribute holders attributes description. The attribute list is guaranteed to be returned always in the same order, wich is fixed at compilation time. This allows for fast access to resource by their position rather than by name.
Returns:
An array of Attribute objects, each one containing the description of one single attribute of the resource.
See Also:
Attribute

lookupAttribute

public int lookupAttribute(java.lang.String name)
Lookup up the index of an attribute in our attribute description.
Parameters:
name - The name of the attribute to look for.
Returns:
An integer, positive if found, negative otherwise.

setValue

public void setValue(int idx,
                     java.lang.Object value)
Set an attribute value. This method sets the value of some attribute of the resource. It marks the resource as being modified, and alert its resource store (so that it knows it will have to save the object at some time in the future).
Parameters:
idx - The attribute index, in the list of attributes advertized by the resource.
value - The new value for this attribute.
Throws:
IllegalAttributeAccess - if the provided value doesn't match the attribute expected type.

setValue

public void setValue(java.lang.String name,
                     java.lang.Object value)
Set an attribute value. This method sets the value of an attribute, referenced by its name.
Parameters:
name - The attribute name.
value - The new value for the attribute.
Throws:
IllegalAttributeAccess - if the provided value doesn't match the attribute expected type.

setBoolean

public void setBoolean(int idx,
                       boolean b)

setChar

public void setChar(int idx,
                    char ch)
             throws IllegalAttributeAccess

setDouble

public void setDouble(int idx,
                      double d)
               throws IllegalAttributeAccess

setFloat

public void setFloat(int idx,
                     float f)
              throws IllegalAttributeAccess

setInt

public void setInt(int idx,
                   int i)
            throws IllegalAttributeAccess

setLong

public void setLong(int idx,
                    long l)
             throws IllegalAttributeAccess

setString

public void setString(int idx,
                      java.lang.String s)
               throws IllegalAttributeAccess

getValue

public java.lang.Object getValue(int idx,
                                 java.lang.Object def)
                          throws IllegalAttributeAccess
Generic get of an attribute value. Retreive an attribute value from its index in the resource's attribute list.
Parameters:
idx - The index of the attribute whose value is queried.
def - The default value (if the attribute isn't defined).
Returns:
An object, giving the attribute value, or the provided default if this attribute isn't currently define for the resource.
Throws:
IllegalAttributeAccess - if the given index doesn't match any of the resource's attributes.

getValue

public java.lang.Object getValue(java.lang.String name,
                                 java.lang.Object def)
                          throws IllegalAttributeAccess
Generic get of an attribute value. Get the method of an attribute, by name.
Parameters:
name - The name of the queried attribute.
def - The default value.
Throws:
IllegalAttributeAccess - if the given name doesn't match any of the attribute's name.

getBoolean

public boolean getBoolean(int idx,
                          boolean def)

getChar

public char getChar(int idx,
                    char def)

getDouble

public double getDouble(int idx,
                        double def)

getFloat

public float getFloat(int idx,
                      float def)

getInt

public int getInt(int idx,
                  int def)

getLong

public long getLong(int idx,
                    long def)

getString

public java.lang.String getString(int idx,
                                  java.lang.String def)

definesAttribute

public boolean definesAttribute(int idx)
                         throws IllegalAttributeAccess
Does this resource has defined a value for the given attribute.
Parameters:
idx - The index of the attribute to check.
Returns:
A boolean true if the resource has a value for this attribute, false otherwise.

definesAttribute

public boolean definesAttribute(java.lang.String name)
                         throws IllegalAttributeAccess
Does this resource has defined a value for the given attribute.
Parameters:
name - The name of the attribute to check.
Returns:
A boolean true if the resource has a value for this attribute, false otherwise.

pickle

public void pickle(java.io.DataOutputStream out)
            throws java.io.IOException
Pickle this attribute holder to the given stream.
Parameters:
out - The output stream we should pickle ourselve to.
Throws:
java.io.IOException - If some IO error occured during pickling.

unpickle

public static AttributeHolder unpickle(java.io.DataInputStream in,
                                       java.util.Hashtable defs,
                                       boolean init)
                                throws java.io.IOException
Unpickle an attribute holder from the given input stream. AttributeHolder unpickling is done in two stage: the first stage wich is not redefinable, consists in recreating an instance of the attribute holder (this method).

The second stage restore the instance attributes (and whatever information the pickle method as written there). This is the unpickleInstance method.

Parameters:
defs - Set of default values for the holder.
in - The input stream to read from.
init - Should the resource be initialized ?
Returns:
An instance of AttributeHolder of one of its subclass.
Throws:
java.io.IOException - If some IO error occured while reading the stream.

unpickle

public static AttributeHolder unpickle(java.io.DataInputStream in,
                                       java.util.Hashtable defs)
                                throws java.io.IOException
A short hand for unpickling and initializing a resource.
Parameters:
defs - Set of default values for the holder.
in - The input stream to read from.
init - Should the resource be initialized ?
Returns:
An instance of AttributeHolder of one of its subclass.
Throws:
java.io.IOException - If some IO error occured while reading the stream.

unpickleInstance

public AttributeHolder unpickleInstance(java.io.DataInputStream in,
                                        java.util.Hashtable defs,
                                        boolean init)
                                 throws java.io.IOException
Finish the instance part of the unpickling job. The standard way of redefining how your attribute holder should be pickled is as follow:
Parameters:
in - The input stream to read from.
defs - The proposed attribute default values.
init - Should we initialize the resource after unpickling.

unpickleInstance

public AttributeHolder unpickleInstance(java.io.DataInputStream in,
                                        java.util.Hashtable defs)
                                 throws java.io.IOException
A short-hand for unpickling and initializing resources.
Parameters:
in - The input stream to read.
defs - The default attribute values.
Returns:
An AttributeHolder instance.

unpickle

public static AttributeHolder unpickle(java.io.DataInputStream in)
                                throws java.io.IOException
Unpickle an attribute holder from the given input stream.
Parameters:
in - The input stream to read from.
Returns:
An instance of AttributeHolder of one of its subclass.
Throws:
java.io.IOException - If some IO error occured while reading the stream.

initialize

public void initialize(java.lang.Object[] values)
Initialization method for attribute holders. Each time an attribute holder get restored, its initialize method gets called. The holder should initialize itself with the set of provided values and perform any additional startup code.
Parameters:
values - The attribute values the holder should initialize from.

initialize

public void initialize(java.util.Hashtable defs)
Initialization method for attribute holders. This method allows to initialize an attribute holder by providing its attributes values through a Hashtable mapping attribute names to attribute values.
Parameters:
defs - The Hashtable containing the default values.

print

public void print(java.io.PrintStream out)
Debugging purposes only, print this attribute holder.
Parameters:
out - The print stream to print to.