java.util.jar

Class Attributes

public class Attributes extends Object implements Cloneable, Map<Object,Object>

Represents attribute name/value pairs from a Manifest as a Map. The names of an attribute are represented by the Attributes.Name class and should confirm to the restrictions described in that class. Note that the Map interface that Attributes implements allows you to put names and values into the attribute that don't follow these restriction (and are not really Atrribute.Names, but if you do that it might cause undefined behaviour later).

If you use the constants defined in the inner class Name then you can be sure that you always access the right attribute names. This makes manipulating the Attributes more or less type safe.

Most of the methods are wrappers to implement the Map interface. The really useful and often used methods are getValue(Name) and getValue(String). If you actually want to set attributes you may want to use the putValue(String, String) method (sorry there is no public type safe putValue(Name, String) method).

See Also: Name

Nested Class Summary
static class	Attributes.Name Represents a name of a Manifest Attribute.

Field Summary
protected Map<Object,Object>	map The map that holds all the attribute name/value pairs.

Constructor Summary
	Attributes() Creates an empty Attributes map.
	Attributes(int size) Creates an empty Attributes map with the given initial size.
	Attributes(Attributes attr) Creates an Attributes map with the initial values taken from another Attributes map.

Method Summary
void	clear() Removes all attributes.
Object	clone() Return a clone of this attribute map.
boolean	containsKey(Object attrName) Checks to see if there is an attribute with the specified name.
boolean	containsValue(Object attrValue) Checks to see if there is an attribute name with the specified value.
Set<Entry<Object,Object>>	entrySet() Gives a Set of attribute name and values pairs as MapEntries.
boolean	equals(Object o) Checks to see if two Attributes are equal.
Object	get(Object attrName) Gets the value of a specified attribute name.
String	getValue(String name) Gets the value of an attribute name given as a String.
String	getValue(Attributes.Name name) Gets the value of the given attribute name.
int	hashCode() Returns the hashcode of the attribute name/value map.
boolean	isEmpty() Returns true if there are no attributes set, false otherwise.
Set<Object>	keySet() Gives a Set of all the values of defined attribute names.
Object	put(Object name, Object value) Adds or replaces a attribute name/value pair.
void	putAll(Map<?,?> attr) Adds or replaces all attribute name/value pairs from another Attributes object to this one.
String	putValue(String name, String value) Stores an attribute name (represented by a String) and value in this Attributes map.
Object	remove(Object name) Remove a attribute name/value pair.
int	size() Returns the number of defined attribute name/value pairs.
Collection<Object>	values() Returns all the values of the defined attribute name/value pairs as a Collection.

Field Detail

map

protected Map<Object,Object> map

The map that holds all the attribute name/value pairs. In this implementation it is actually a Hashtable, but that can be different in other implementations.

Constructor Detail

Attributes

public Attributes()

Creates an empty Attributes map.

Attributes

public Attributes(int size)

Creates an empty Attributes map with the given initial size.

Parameters: size the initial size of the underlying map

Attributes

public Attributes(Attributes attr)

Creates an Attributes map with the initial values taken from another Attributes map.

Parameters: attr Attributes map to take the initial values from

Method Detail

clear

public void clear()

Removes all attributes.

clone

public Object clone()

Return a clone of this attribute map.

containsKey

public boolean containsKey(Object attrName)

Checks to see if there is an attribute with the specified name. XXX - what if the object is a String?

Parameters: attrName the name of the attribute to check

Returns: true if there is an attribute with the specified name, false otherwise

containsValue

public boolean containsValue(Object attrValue)

Checks to see if there is an attribute name with the specified value.

Parameters: attrValue the value of a attribute to check

Returns: true if there is an attribute name with the specified value, false otherwise

entrySet

public Set<Entry<Object,Object>> entrySet()

Gives a Set of attribute name and values pairs as MapEntries.

Returns: a set of attribute name value pairs

equals

public boolean equals(Object o)

Checks to see if two Attributes are equal. The supplied object must be a real instance of Attributes and contain the same attribute name/value pairs.

Parameters: o another Attribute object which should be checked for equality

Returns: true if the object is an instance of Attributes and contains the same name/value pairs, false otherwise

get

public Object get(Object attrName)

Gets the value of a specified attribute name. XXX - what if the object is a String?

Parameters: attrName the name of the attribute we want the value of

Returns: the value of the specified attribute name or null when there is no such attribute name

getValue

public String getValue(String name)

Gets the value of an attribute name given as a String.

Parameters: name a String describing the Name to look for

Returns: the value gotten from the map of null when not found

getValue

public String getValue(Attributes.Name name)

Gets the value of the given attribute name.

Parameters: name the Name to look for

Returns: the value gotten from the map of null when not found

hashCode

public int hashCode()

Returns the hashcode of the attribute name/value map.

isEmpty

public boolean isEmpty()

Returns true if there are no attributes set, false otherwise.

keySet

public Set<Object> keySet()

Gives a Set of all the values of defined attribute names.

put

public Object put(Object name, Object value)

Adds or replaces a attribute name/value pair. XXX - What if the name is a string? What if the name is neither a Name nor a String? What if the value is not a string?

Parameters: name the name of the attribute value the (new) value of the attribute

Returns: the old value of the attribute or null when there was no old attribute with this name

putAll

public void putAll(Map<?,?> attr)

Adds or replaces all attribute name/value pairs from another Attributes object to this one. The supplied Map must be an instance of Attributes.

Parameters: attr the Attributes object to merge with this one

Throws: ClassCastException if the supplied map is not an instance of Attributes

putValue

public String putValue(String name, String value)

Stores an attribute name (represented by a String) and value in this Attributes map. When the (case insensitive string) name already exists the value is replaced and the old value is returned.

Parameters: name a (case insensitive) String representation of the attribite name to add/replace value the (new) value of the attribute name

UNKNOWN: the old value of the attribute name or null if it didn't exist yet

remove

public Object remove(Object name)

Remove a attribute name/value pair. XXX - What if the name is a String?

Parameters: name the name of the attribute name/value pair to remove

Returns: the old value of the attribute or null if the attribute didn't exist

size

public int size()

Returns the number of defined attribute name/value pairs.

values

public Collection<Object> values()

Returns all the values of the defined attribute name/value pairs as a Collection.