java.util.jar
Class Attributes
- Implemented Interfaces:
- Cloneable, Map<K,V>
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).
Nested Class Summary
Field Summary
protected Map Object>map - The map that holds all the attribute name/value pairs.
Constructor Summary
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.
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.
boolean equals(Object o)- Checks to see if two Attributes are equal.
int hashCode()- Returns the hashcode of the attribute name/value map.
boolean isEmpty()- Returns true if there are no attributes set, false otherwise.
Set keySet()- Gives a Set of all the values of defined attribute names.
void putAll(Map attr)- Adds or replaces all attribute name/value pairs from another
Attributes object to this one.
int size()- Returns the number of defined attribute name/value pairs.
Collection values()- Returns all the values of the defined attribute name/value pairs as a
Collection.
Methods inherited from class java.lang.Object
clone,
equals,
extends Object> getClass,
finalize,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Field Details
Object>map
protected MapObject>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 Details
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 Details
Object>> entrySet
public Set
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?
- Specified by:
- containsKey in interface Map<K,V>
- 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.
- Specified by:
- containsValue in interface Map<K,V>
- Parameters:
attrValue - the value of a attribute to check
- Returns:
- true if there is an attribute name with the specified value,
false otherwise
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.
- Specified by:
- equals in interface Map<K,V>
- Overrides:
- equals in interface Object
- 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?
- Specified by:
- get in interface Map<K,V>
- 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
isEmpty
public boolean isEmpty()
Returns true if there are no attributes set, false otherwise.
- Specified by:
- isEmpty in interface Map<K,V>
keySet
public Set keySet()
Gives a Set of all the values of defined attribute names.
- Specified by:
- keySet in interface Map<K,V>
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 attributevalue - 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
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/replacevalue - the (new) value of the attribute name
remove
public Object remove(Object name)
Remove a attribute name/value pair.
XXX - What if the name is a String?
- Specified by:
- remove in interface Map<K,V>
- 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.
- Specified by:
- size in interface Map<K,V>
values
public Collection values()
Returns all the values of the defined attribute name/value pairs as a
Collection.
- Specified by:
- values in interface Map<K,V>
Attributes.java -- Represents attribute name/value pairs from a Manifest
Copyright (C) 2000, 2002, 2005 Free Software Foundation, Inc.
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