Package fr.dyade.aaa.common.stream

Class Properties

java.lang.Object

fr.dyade.aaa.common.stream.Properties

All Implemented Interfaces:

Encodable, Serializable, Cloneable

public final class Properties
extends Object
implements Serializable, Cloneable, Encodable

This class implements a set of properties, which maps keys to values. Only string object can be used as a key, all primitives type can be used as a value.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Properties.EmptyEnumerator	A hashtable enumerator class for empty hash tables, specializes the general Enumerator
private static class	Properties.Entry	Properties collision list.
private class	Properties.Enumerator	A hashtable enumerator class.

Field Summary

Fields

Modifier and Type	Field	Description
private int	count	The total number of entries in the hash table.
private static Properties.EmptyEnumerator	emptyEnumerator
private static int	KEYS
private float	loadFactor	The load factor for the hashtable.
private Properties.Entry[]	table	The hash table data.
private int	threshold	The table is rehashed when its size exceeds this threshold.
private static int	VALUES

Fields inherited from interface fr.dyade.aaa.common.encoding.Encodable

BOOLEAN_ENCODED_SIZE, BYTE_ENCODED_SIZE, DOUBLE_ENCODED_SIZE, FLOAT_ENCODED_SIZE, INT_ENCODED_SIZE, LONG_ENCODED_SIZE, SHORT_ENCODED_SIZE

Constructor Summary

Constructors

Constructor	Description
Properties()	Constructs a new, empty hashtable with a default initial capacity (11) and load factor, which is 0.75.
Properties(int initialCapacity)	Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.
Properties(int initialCapacity, float loadFactor)	Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears this hashtable so that it contains no keys.
Object	clone()	Creates a shallow copy of this hashtable.
boolean	containsKey(String key)	Tests if the specified object is a key in this hashtable.
void	copyInto(Map h)
void	decode(Decoder decoder)	Decodes the content of this object
Enumeration	elements()	Returns an enumeration of the values in this hashtable.
void	encode(Encoder encoder)	Encodes the content of this object
boolean	equals(Object o)
Object	get(String key)	Returns the value to which the specified key is mapped in this hashtable.
int	getEncodableClassId()	Returns a unique class identifier.
int	getEncodedSize()	Returns the size of the byte array that results from the encoding of this object.
private Enumeration	getEnumeration(int type)
int	hashCode()	Returns the hash code value for this Map as per the definition in the Map interface.
private void	initialize(int initialCapacity, float loadFactor)
boolean	isEmpty()	Tests if this hashtable maps no keys to values.
Enumeration	keys()	Returns an enumeration of the keys in this hashtable.
static void	objectToJSon(Object obj, Appendable appendable)
Object	put(String key, Object value)	Maps the specified key to the specified value in this hashtable.
static Properties	readFrom(InputStream is)	The object implements the readFrom method to restore its contents from the input stream.
void	readFrom(InputStream is, int count)
private void	readObject(ObjectInputStream in)
protected void	rehash()	Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently.
Object	remove(String key)	Removes the key (and its corresponding value) from this hashtable.
Object	setProperty(String key, Object value)	Calls the method put.
int	size()	Returns the number of keys in this hashtable.
void	toJSon(Appendable appendable)
String	toString()	Returns a string representation of this Properties object in the form of a set of entries, enclosed in braces and separated by the ASCII characters ", " (comma and space).
private void	writeObject(ObjectOutputStream out)
void	writeTo(OutputStream os)	The object implements the writeTo method to write its contents to the output stream.

Methods inherited from class java.lang.Object

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

Field Detail

count

private transient int count

The total number of entries in the hash table.

table

private transient Properties.Entry[] table

The hash table data.

threshold

private transient int threshold

The table is rehashed when its size exceeds this threshold. (The value of this field is (int)(capacity * loadFactor).)

loadFactor

private transient float loadFactor

The load factor for the hashtable.

KEYS

private static final int KEYS

See Also:

Constant Field Values

VALUES

private static final int VALUES

See Also:

Constant Field Values

emptyEnumerator

private static Properties.EmptyEnumerator emptyEnumerator

Constructor Detail

Properties

public Properties(int initialCapacity,
                  float loadFactor)

Constructs a new, empty hashtable with the specified initial capacity and the specified load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable.

loadFactor - the load factor of the hashtable.

Throws:

IllegalArgumentException - if the initial capacity is less than zero, or if the load factor is nonpositive.

Properties

public Properties(int initialCapacity)

Constructs a new, empty hashtable with the specified initial capacity and default load factor, which is 0.75.

Parameters:

initialCapacity - the initial capacity of the hashtable.

Throws:

IllegalArgumentException - if the initial capacity is less than zero.

Properties

public Properties()

Constructs a new, empty hashtable with a default initial capacity (11) and load factor, which is 0.75.

Method Detail

initialize

private void initialize(int initialCapacity,
                        float loadFactor)

size

public int size()

Returns the number of keys in this hashtable.

Returns:

the number of keys in this hashtable.

isEmpty

public boolean isEmpty()

Tests if this hashtable maps no keys to values.

Returns:

true if this hashtable maps no keys to values; false otherwise.

keys

public Enumeration keys()

Returns an enumeration of the keys in this hashtable.

Returns:

an enumeration of the keys in this hashtable.

See Also:

Enumeration, elements()

elements

public Enumeration elements()

Returns an enumeration of the values in this hashtable. Use the Enumeration methods on the returned object to fetch the elements sequentially.

Returns:

an enumeration of the values in this hashtable.

See Also:

Enumeration, Map

containsKey

public boolean containsKey(String key)

Tests if the specified object is a key in this hashtable.

Parameters:

key - possible key.

Returns:

true if and only if the specified object is a key in this hashtable, as determined by the equals method; false otherwise.

Throws:

NullPointerException - if the key is null.

get

public Object get(String key)

Returns the value to which the specified key is mapped in this hashtable.

Parameters:

key - a key in the hashtable.

Returns:

the value to which the key is mapped in this hashtable; null if the key is not mapped to any value in this hashtable.

Throws:

NullPointerException - if the key is null.

rehash

protected void rehash()

Increases the capacity of and internally reorganizes this hashtable, in order to accommodate and access its entries more efficiently. This method is called automatically when the number of keys in the hashtable exceeds this hashtable's capacity and load factor.

setProperty

public Object setProperty(String key,
                          Object value)
                   throws ClassCastException

Calls the method put.

Provided to Enforce the use of primitive type for values. The value returned is the result of the call to put.

Parameters:

key - the key to be placed into this property object.

value - the value corresponding to key.

Returns:

the previous value of the specified key in this property object, or null if it did not have one.

Throws:

ClassCastException

put

public Object put(String key,
                  Object value)

Maps the specified key to the specified value in this hashtable. Neither the key nor the value can be null.

The value can be retrieved by calling the get method with a key that is equal to the original key. Be careful only primitive type can be used as value, in the other case an exception will be thrown at serialization.

Parameters:

key - the hashtable key.

value - the value.

Returns:

the previous value of the specified key in this hashtable, or null if it did not have one.

Throws:

NullPointerException - if the key or value is null.

See Also:

Object.equals(Object)

remove

public Object remove(String key)

Removes the key (and its corresponding value) from this hashtable. This method does nothing if the key is not in the hashtable.

Parameters:

key - the key that needs to be removed.

Returns:

the value to which the key had been mapped in this hashtable, or null if the key did not have a mapping.

Throws:

NullPointerException - if the key is null.

clear

public void clear()

Clears this hashtable so that it contains no keys.

clone

public Object clone()

Creates a shallow copy of this hashtable. All the structure of the hashtable itself is copied, but the keys and values are not cloned. This is a relatively expensive operation.

Overrides:

clone in class Object

Returns:

a clone of the hashtable.

toString

public String toString()

Returns a string representation of this Properties object in the form of a set of entries, enclosed in braces and separated by the ASCII characters ", " (comma and space). Each entry is rendered as the key, an equals sign =, and the associated element, where the toString method is used to convert the key and element to strings.

Overrides to toString method of Object.

Overrides:

toString in class Object

Returns:

a string representation of this hashtable.

toJSon

public void toJSon(Appendable appendable)
            throws IOException

Throws:

IOException

objectToJSon

public static void objectToJSon(Object obj,
                                Appendable appendable)
                         throws IOException

Throws:

IOException

getEnumeration

private Enumeration getEnumeration(int type)

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns the hash code value for this Map as per the definition in the Map interface.

Overrides:

hashCode in class Object

Since:

1.2

See Also:

Map.hashCode()

copyInto

public void copyInto(Map h)

writeTo

public void writeTo(OutputStream os)
             throws IOException

The object implements the writeTo method to write its contents to the output stream.

Parameters:

os - the stream to write the object to.

Throws:

IOException - an error occurs during writing.

readFrom

public static Properties readFrom(InputStream is)
                           throws IOException

The object implements the readFrom method to restore its contents from the input stream.

Parameters:

is - the stream to read data from in order to restore the object

Returns:

the properties object read.

Throws:

IOException - an error occurs during writing.

readFrom

public void readFrom(InputStream is,
                     int count)
              throws IOException

Throws:

IOException

writeObject

private void writeObject(ObjectOutputStream out)
                  throws IOException

Throws:

IOException

readObject

private void readObject(ObjectInputStream in)
                 throws IOException,
                        ClassNotFoundException

Throws:

IOException

ClassNotFoundException

getEncodedSize

public int getEncodedSize()
                   throws IOException

Description copied from interface: Encodable

Returns the size of the byte array that results from the encoding of this object.

Specified by:

getEncodedSize in interface Encodable

Returns:

the size of the encoded byte array

Throws:

IOException

getEncodableClassId

public int getEncodableClassId()

Description copied from interface: Encodable

Returns a unique class identifier.

Specified by:

getEncodableClassId in interface Encodable

Returns:

a unique class identifier

encode

public void encode(Encoder encoder)
            throws Exception

Description copied from interface: Encodable

Encodes the content of this object

Specified by:

encode in interface Encodable

Parameters:

encoder - the encoder to be used for the encoding

Throws:

Exception - if an error occurs

decode

public void decode(Decoder decoder)
            throws Exception

Description copied from interface: Encodable

Decodes the content of this object

Specified by:

decode in interface Encodable

Parameters:

decoder - the decoder to be used for the decoding

Throws:

Exception - if an error occurs