com.ibm.opencard.service
Class MFCCardObjectInfoCache
java.lang.Object
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+--java.util.Dictionary
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+--com.ibm.opencard.service.MFCCardObjectInfoCache
- public class MFCCardObjectInfoCache
- extends java.util.Dictionary
A cache for information about objects located on a smartcard.
The information to be stored are instances of MFCCardObjectInfo
or derived classes. Examples for objects located on a smartcard are
files and keys. The information on those objects includes access
information.
To store and retrieve object information from this cache, a key has to
be used to specify the object to which information is related. For files,
this will be the file path. For keys, it may be the path to a file in
which the key is stored, or to a directory in which several files hold
the key information.
This cache uses a hashtable to maintain the association between keys
and information objects. The abstract methods defined in the base class
Dictionary are mapped to their implementation in the hashtable.
Use of these methods, especially to modify the contents of the cache, is
strongly discouraged.
Some additional methods are provided that restrict the type of the objects
stored in the cache from Object to MFCCardObjectInfo.
These methods are
cacheObjectInfo to store,
lookupObjectInfo to retrieve, and
removeObjectInfo to delete information in or from the cache.
- Version:
- $Id: MFCCardObjectInfoCache.java,v 1.1 1999/12/02 16:06:07 damke Exp $
- See Also:
MFCCardObjectInfo,
Dictionary,
Hashtable,
cacheObjectInfo(java.lang.Object, com.ibm.opencard.service.MFCCardObjectInfo),
lookupObjectInfo(java.lang.Object),
removeObjectInfo(java.lang.Object)
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Method Summary |
void |
cacheObjectInfo(java.lang.Object key,
MFCCardObjectInfo info)
Store some object information in the cache.
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java.util.Enumeration |
elements()
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java.lang.Object |
get(java.lang.Object key)
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boolean |
isEmpty()
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java.util.Enumeration |
keys()
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MFCCardObjectInfo |
lookupObjectInfo(java.lang.Object key)
Retrieve some object information from the cache.
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java.lang.Object |
put(java.lang.Object key,
java.lang.Object value)
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java.lang.Object |
remove(java.lang.Object key)
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void |
removeObjectInfo(java.lang.Object key)
Delete some object information from the cache.
if the cache contains information about the object identified by the
key, this information will be removed from the cache. |
int |
size()
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| Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
MFCCardObjectInfoCache
public MFCCardObjectInfoCache()
size
public final int size()
- Overrides:
- size in class java.util.Dictionary
isEmpty
public final boolean isEmpty()
- Overrides:
- isEmpty in class java.util.Dictionary
keys
public final java.util.Enumeration keys()
- Overrides:
- keys in class java.util.Dictionary
elements
public final java.util.Enumeration elements()
- Overrides:
- elements in class java.util.Dictionary
get
public final java.lang.Object get(java.lang.Object key)
- Overrides:
- get in class java.util.Dictionary
put
public final java.lang.Object put(java.lang.Object key,
java.lang.Object value)
- Overrides:
- put in class java.util.Dictionary
remove
public final java.lang.Object remove(java.lang.Object key)
- Overrides:
- remove in class java.util.Dictionary
cacheObjectInfo
public final void cacheObjectInfo(java.lang.Object key,
MFCCardObjectInfo info)
- Store some object information in the cache.
The key passed as argument identifies an object located on the smartcard
for which information is to be stored. If the cache already contains
information on that object, it will be replaced by the one that
is passed as an argument. The information can be retrieved by invoking
lookupObjectInfo and deleted using removeObjectInfo.
The key specified has to obey the contract for the methods equals
and hashCode specified in the documentation of Object.
Especially, it may not change any attributes evaluated in any of these
methods while it is stored in the cache. If the key's class allows such
changes, make sure to pass a copy of the key which can be compared
to other keys using equals, but will not be changed since it's
identity is not passed to the outside world.
- Parameters:
key - an identifier for the object located on the smartcardinfo - the information to store in the cache- See Also:
lookupObjectInfo(java.lang.Object),
removeObjectInfo(java.lang.Object),
Object.equals(java.lang.Object),
Object.hashCode()
lookupObjectInfo
public final MFCCardObjectInfo lookupObjectInfo(java.lang.Object key)
- Retrieve some object information from the cache.
If object information has been stored in the cache by a preceeding
invocation of cacheObjectInfo with an equal key, and this
information has not yet been removed from the cache by an invocation
of removeObjectInfo, this information will be returned.
Otherwise, null is returned.
The key passed as argument and the key that has been passed when the
information to retrieve was stored must be equal with respect to their
implementations of the equals method. Also, hashCode
has to return the same value for both.
- Parameters:
key - an identifier for the object located on the smartcard- Returns:
- any available information on that object
- See Also:
cacheObjectInfo(java.lang.Object, com.ibm.opencard.service.MFCCardObjectInfo),
removeObjectInfo(java.lang.Object),
Object.equals(java.lang.Object),
Object.hashCode()
removeObjectInfo
public final void removeObjectInfo(java.lang.Object key)
- Delete some object information from the cache.
if the cache contains information about the object identified by the
key, this information will be removed from the cache. Otherwise,
nothing will be done.
See cacheObjectInfo and lookupObjectInfo for details
on keys, and how information can be stored in or retrieved from the
cache.
- Parameters:
key - an identifier for the object located on the smartcard- See Also:
cacheObjectInfo(java.lang.Object, com.ibm.opencard.service.MFCCardObjectInfo),
removeObjectInfo(java.lang.Object)
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