Provider
public
abstract
class
Provider
extends Properties
java.lang.Object | ||||
↳ | java.util.Dictionary<java.lang.Object, java.lang.Object> | |||
↳ | java.util.Hashtable<java.lang.Object, java.lang.Object> | |||
↳ | java.util.Properties | |||
↳ | java.security.Provider |
This class represents a "provider" for the Java Security API, where a provider implements some or all parts of Java Security. Services that a provider may implement include:
- Algorithms (such as DSA, RSA, MD5 or SHA-1).
- Key generation, conversion, and management facilities (such as for algorithm-specific keys).
Each provider has a name and a version number, and is configured in each runtime it is installed in.
See The Provider Class in the "Java Cryptography Architecture API Specification & Reference" for information about how a particular type of provider, the cryptographic service provider, works and is installed. However, please note that a provider can be used to implement any security service in Java that uses a pluggable architecture with a choice of implementations that fit underneath.
Some provider implementations may encounter unrecoverable internal
errors during their operation, for example a failure to communicate with a
security token. A ProviderException
should be used to indicate
such errors.
The service type Provider
is reserved for use by the
security framework. Services of this type cannot be added, removed,
or modified by applications.
The following attributes are automatically placed in each Provider object:
Name | Value |
---|---|
Provider.id name |
String.valueOf(provider.getName()) |
Provider.id version |
String.valueOf(provider.getVersion()) |
Provider.id info |
String.valueOf(provider.getInfo()) |
Provider.id className |
provider.getClass().getName() |
Summary
Nested classes | |
---|---|
class |
Provider.Service
The description of a security service. |
Inherited fields |
---|
Protected constructors | |
---|---|
Provider(String name, double version, String info)
Constructs a provider with the specified name, version number, and information. |
Public methods | |
---|---|
void
|
clear()
Clears this provider so that it no longer contains the properties used to look up facilities implemented by the provider. |
Object
|
compute(Object key, BiFunction<? super Object, ? super Object, ?> remappingFunction)
Attempts to compute a mapping for the specified key and its
current mapped value (or |
Object
|
computeIfAbsent(Object key, Function<? super Object, ?> mappingFunction)
If the specified key is not already associated with a value (or
is mapped to |
Object
|
computeIfPresent(Object key, BiFunction<? super Object, ? super Object, ?> remappingFunction)
If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value. |
Enumeration<Object>
|
elements()
Returns an enumeration of the values in this hashtable. |
Set<Entry<Object, Object>>
|
entrySet()
Returns an unmodifiable Set view of the property entries contained in this Provider. |
void
|
forEach(BiConsumer<? super Object, ? super Object> action)
Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. |
Object
|
get(Object key)
Returns the value to which the specified key is mapped,
or |
String
|
getInfo()
Returns a human-readable description of the provider and its services. |
String
|
getName()
Returns the name of this provider. |
Object
|
getOrDefault(Object key, Object defaultValue)
Returns the value to which the specified key is mapped, or
|
String
|
getProperty(String key)
Searches for the property with the specified key in this property list. |
Provider.Service
|
getService(String type, String algorithm)
Get the service describing this Provider's implementation of the specified type of this algorithm or alias. |
Set<Provider.Service>
|
getServices()
Get an unmodifiable Set of all services supported by this Provider. |
double
|
getVersion()
Returns the version number for this provider. |
Set<Object>
|
keySet()
Returns an unmodifiable Set view of the property keys contained in this provider. |
Enumeration<Object>
|
keys()
Returns an enumeration of the keys in this hashtable. |
void
|
load(InputStream inStream)
Reads a property list (key and element pairs) from the input stream. |
Object
|
merge(Object key, Object value, BiFunction<? super Object, ? super Object, ?> remappingFunction)
If the specified key is not already associated with a value or is associated with null, associates it with the given value. |
Object
|
put(Object key, Object value)
Sets the |
void
|
putAll(Map<?, ?> t)
Copies all of the mappings from the specified Map to this provider. |
Object
|
putIfAbsent(Object key, Object value)
If the specified key is not already associated with a value (or is mapped
to |
boolean
|
remove(Object key, Object value)
Removes the entry for the specified key only if it is currently mapped to the specified value. |
Object
|
remove(Object key)
Removes the |
Object
|
replace(Object key, Object value)
Replaces the entry for the specified key only if it is currently mapped to some value. |
boolean
|
replace(Object key, Object oldValue, Object newValue)
Replaces the entry for the specified key only if currently mapped to the specified value. |
void
|
replaceAll(BiFunction<? super Object, ? super Object, ?> function)
Replaces each entry's value with the result of invoking the given function on that entry, in the order entries are returned by an entry set iterator, until all entries have been processed or the function throws an exception. |
String
|
toString()
Returns a string with the name and the version number of this provider. |
Collection<Object>
|
values()
Returns an unmodifiable Collection view of the property values contained in this provider. |
Protected methods | |
---|---|
void
|
putService(Provider.Service s)
Add a service. |
void
|
removeService(Provider.Service s)
Remove a service previously added using
|
Inherited methods | |
---|---|
Protected constructors
Provider
protected Provider (String name, double version, String info)
Constructs a provider with the specified name, version number, and information.
Parameters | |
---|---|
name |
String : the provider name. |
version |
double : the provider version number. |
info |
String : a description of the provider and its services. |
Public methods
clear
public void clear ()
Clears this provider so that it no longer contains the properties used to look up facilities implemented by the provider.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "clearProviderProperties."+name
(where name
is the provider name) to see if it's ok to clear
this provider.
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to clear this provider |
compute
public Object compute (Object key, BiFunction<? super Object, ? super Object, ?> remappingFunction)
Attempts to compute a mapping for the specified key and its
current mapped value (or null
if there is no current
mapping).
If a security manager is enabled, its checkSecurityAccess
method is called with the strings "putProviderProperty."+name
and "removeProviderProperty."+name
, where name
is the
provider name, to see if it's ok to set this provider's property values
and remove this provider's properties.
Parameters | |
---|---|
key |
Object : key with which the specified value is to be associated |
remappingFunction |
BiFunction : the remapping function to compute a value |
Returns | |
---|---|
Object |
the new value associated with the specified key, or null if none |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values or remove properties. |
computeIfAbsent
public Object computeIfAbsent (Object key, Function<? super Object, ?> mappingFunction)
If the specified key is not already associated with a value (or
is mapped to null
), attempts to compute its value using
the given mapping function and enters it into this map unless
null
.
If a security manager is enabled, its checkSecurityAccess
method is called with the strings "putProviderProperty."+name
and "removeProviderProperty."+name
, where name
is the
provider name, to see if it's ok to set this provider's property values
and remove this provider's properties.
Parameters | |
---|---|
key |
Object : key with which the specified value is to be associated |
mappingFunction |
Function : the mapping function to compute a value |
Returns | |
---|---|
Object |
the current (existing or computed) value associated with the specified key, or null if the computed value is null |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values and remove properties. |
computeIfPresent
public Object computeIfPresent (Object key, BiFunction<? super Object, ? super Object, ?> remappingFunction)
If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
If a security manager is enabled, its checkSecurityAccess
method is called with the strings "putProviderProperty."+name
and "removeProviderProperty."+name
, where name
is the
provider name, to see if it's ok to set this provider's property values
and remove this provider's properties.
Parameters | |
---|---|
key |
Object : key with which the specified value is to be associated |
remappingFunction |
BiFunction : the remapping function to compute a value |
Returns | |
---|---|
Object |
the new value associated with the specified key, or null if none |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values or remove properties. |
elements
public Enumeration<Object> elements ()
Returns an enumeration of the values in this hashtable. Use the Enumeration methods on the returned object to fetch the elements sequentially. If the hashtable is structurally modified while enumerating over the values then the results of enumerating are undefined.
Returns | |
---|---|
Enumeration<Object> |
an enumeration of the values in this hashtable. |
entrySet
public Set<Entry<Object, Object>> entrySet ()
Returns an unmodifiable Set view of the property entries contained in this Provider.
Returns | |
---|---|
Set<Entry<Object, Object>> |
a set view of the mappings contained in this map |
See also:
forEach
public void forEach (BiConsumer<? super Object, ? super Object> action)
Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. Unless otherwise specified by the implementing class, actions are performed in the order of entry set iteration (if an iteration order is specified.) Exceptions thrown by the action are relayed to the caller.
Parameters | |
---|---|
action |
BiConsumer : The action to be performed for each entry |
get
public Object get (Object key)
Returns the value to which the specified key is mapped,
or null
if this map contains no mapping for the key.
More formally, if this map contains a mapping from a key
k
to a value v
such that (key.equals(k))
,
then this method returns v
; otherwise it returns
null
. (There can be at most one such mapping.)
Parameters | |
---|---|
key |
Object : the key whose associated value is to be returned |
Returns | |
---|---|
Object |
the value to which the specified key is mapped, or
null if this map contains no mapping for the key |
getInfo
public String getInfo ()
Returns a human-readable description of the provider and its services. This may return an HTML page, with relevant links.
Returns | |
---|---|
String |
a description of the provider and its services. |
getName
public String getName ()
Returns the name of this provider.
Returns | |
---|---|
String |
the name of this provider. |
getOrDefault
public Object getOrDefault (Object key, Object defaultValue)
Returns the value to which the specified key is mapped, or
defaultValue
if this map contains no mapping for the key.
Parameters | |
---|---|
key |
Object : the key whose associated value is to be returned |
defaultValue |
Object : the default mapping of the key |
Returns | |
---|---|
Object |
the value to which the specified key is mapped, or
defaultValue if this map contains no mapping for the key |
getProperty
public String getProperty (String key)
Searches for the property with the specified key in this property list.
If the key is not found in this property list, the default property list,
and its defaults, recursively, are then checked. The method returns
null
if the property is not found.
Parameters | |
---|---|
key |
String : the property key. |
Returns | |
---|---|
String |
the value in this property list with the specified key value. |
getService
public Provider.Service getService (String type, String algorithm)
Get the service describing this Provider's implementation of the
specified type of this algorithm or alias. If no such
implementation exists, this method returns null. If there are two
matching services, one added to this provider using
putService()
and one added via put()
,
the service added via putService()
is returned.
Parameters | |
---|---|
type |
String : the type of service requested
(for example, MessageDigest ) |
algorithm |
String : the case insensitive algorithm name (or alternate
alias) of the service requested (for example, SHA-1 ) |
Returns | |
---|---|
Provider.Service |
the service describing this Provider's matching service or null if no such service exists |
Throws | |
---|---|
NullPointerException |
if type or algorithm is null |
getServices
public Set<Provider.Service> getServices ()
Get an unmodifiable Set of all services supported by this Provider.
Returns | |
---|---|
Set<Provider.Service> |
an unmodifiable Set of all services supported by this Provider |
getVersion
public double getVersion ()
Returns the version number for this provider.
Returns | |
---|---|
double |
the version number for this provider. |
keySet
public Set<Object> keySet ()
Returns an unmodifiable Set view of the property keys contained in this provider.
Returns | |
---|---|
Set<Object> |
a set view of the keys contained in this map |
keys
public Enumeration<Object> keys ()
Returns an enumeration of the keys in this hashtable. Use the Enumeration methods on the returned object to fetch the keys sequentially. If the hashtable is structurally modified while enumerating over the keys then the results of enumerating are undefined.
Returns | |
---|---|
Enumeration<Object> |
an enumeration of the keys in this hashtable. |
load
public void load (InputStream inStream)
Reads a property list (key and element pairs) from the input stream.
Parameters | |
---|---|
inStream |
InputStream : the input stream. |
Throws | |
---|---|
IOException |
if an error occurred when reading from the input stream. |
See also:
merge
public Object merge (Object key, Object value, BiFunction<? super Object, ? super Object, ?> remappingFunction)
If the specified key is not already associated with a value or is associated with null, associates it with the given value. Otherwise, replaces the value with the results of the given remapping function, or removes if the result is null. This method may be of use when combining multiple mapped values for a key.
If a security manager is enabled, its checkSecurityAccess
method is called with the strings "putProviderProperty."+name
and "removeProviderProperty."+name
, where name
is the
provider name, to see if it's ok to set this provider's property values
and remove this provider's properties.
Parameters | |
---|---|
key |
Object : key with which the resulting value is to be associated |
value |
Object : the non-null value to be merged with the existing value
associated with the key or, if no existing value or a null value
is associated with the key, to be associated with the key |
remappingFunction |
BiFunction : the remapping function to recompute a value if
present |
Returns | |
---|---|
Object |
the new value associated with the specified key, or null if no value is associated with the key |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values or remove properties. |
put
public Object put (Object key, Object value)
Sets the key
property to have the specified
value
.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "putProviderProperty."+name
,
where name
is the provider name, to see if it's ok to set this
provider's property values.
Parameters | |
---|---|
key |
Object : the hashtable key |
value |
Object : the value |
Returns | |
---|---|
Object |
the previous value of the specified key in this hashtable,
or null if it did not have one |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values. |
putAll
public void putAll (Map<?, ?> t)
Copies all of the mappings from the specified Map to this provider. These mappings will replace any properties that this provider had for any of the keys currently in the specified Map.
Parameters | |
---|---|
t |
Map : mappings to be stored in this map |
putIfAbsent
public Object putIfAbsent (Object key, Object value)
If the specified key is not already associated with a value (or is mapped
to null
) associates it with the given value and returns
null
, else returns the current value.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "putProviderProperty."+name
,
where name
is the provider name, to see if it's ok to set this
provider's property values.
Parameters | |
---|---|
key |
Object : key with which the specified value is to be associated |
value |
Object : value to be associated with the specified key |
Returns | |
---|---|
Object |
the previous value associated with the specified key, or
null if there was no mapping for the key.
(A null return can also indicate that the map
previously associated null with the key,
if the implementation supports null values.) |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values. |
remove
public boolean remove (Object key, Object value)
Removes the entry for the specified key only if it is currently mapped to the specified value.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "removeProviderProperty."+name
,
where name
is the provider name, to see if it's ok to remove this
provider's properties.
Parameters | |
---|---|
key |
Object : key with which the specified value is associated |
value |
Object : value expected to be associated with the specified key |
Returns | |
---|---|
boolean |
true if the value was removed |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to remove this provider's properties. |
remove
public Object remove (Object key)
Removes the key
property (and its corresponding
value
).
If a security manager is enabled, its checkSecurityAccess
method is called with the string "removeProviderProperty."+name
,
where name
is the provider name, to see if it's ok to remove this
provider's properties.
Parameters | |
---|---|
key |
Object : the key that needs to be removed |
Returns | |
---|---|
Object |
the value to which the key had been mapped in this hashtable,
or null if the key did not have a mapping |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to remove this provider's properties. |
replace
public Object replace (Object key, Object value)
Replaces the entry for the specified key only if it is currently mapped to some value.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "putProviderProperty."+name
,
where name
is the provider name, to see if it's ok to set this
provider's property values.
Parameters | |
---|---|
key |
Object : key with which the specified value is associated |
value |
Object : value to be associated with the specified key |
Returns | |
---|---|
Object |
the previous value associated with the specified key, or
null if there was no mapping for the key.
(A null return can also indicate that the map
previously associated null with the key,
if the implementation supports null values.) |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values. |
replace
public boolean replace (Object key, Object oldValue, Object newValue)
Replaces the entry for the specified key only if currently mapped to the specified value.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "putProviderProperty."+name
,
where name
is the provider name, to see if it's ok to set this
provider's property values.
Parameters | |
---|---|
key |
Object : key with which the specified value is associated |
oldValue |
Object : value expected to be associated with the specified key |
newValue |
Object : value to be associated with the specified key |
Returns | |
---|---|
boolean |
true if the value was replaced |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values. |
replaceAll
public void replaceAll (BiFunction<? super Object, ? super Object, ?> function)
Replaces each entry's value with the result of invoking the given function on that entry, in the order entries are returned by an entry set iterator, until all entries have been processed or the function throws an exception.
If a security manager is enabled, its checkSecurityAccess
method is called with the string "putProviderProperty."+name
,
where name
is the provider name, to see if it's ok to set this
provider's property values.
Parameters | |
---|---|
function |
BiFunction : the function to apply to each entry |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method
denies access to set property values. |
toString
public String toString ()
Returns a string with the name and the version number of this provider.
Returns | |
---|---|
String |
the string with the name and the version number for this provider. |
values
public Collection<Object> values ()
Returns an unmodifiable Collection view of the property values contained in this provider.
Returns | |
---|---|
Collection<Object> |
a collection view of the values contained in this map |
Protected methods
putService
protected void putService (Provider.Service s)
Add a service. If a service of the same type with the same algorithm
name exists and it was added using putService()
,
it is replaced by the new service.
This method also places information about this service
in the provider's Hashtable values in the format described in the
Java Cryptography Architecture API Specification & Reference .
Also, if there is a security manager, its
checkSecurityAccess
method is called with the string
"putProviderProperty."+name
, where name
is
the provider name, to see if it's ok to set this provider's property
values. If the default implementation of checkSecurityAccess
is used (that is, that method is not overriden), then this results in
a call to the security manager's checkPermission
method with
a SecurityPermission("putProviderProperty."+name)
permission.
Parameters | |
---|---|
s |
Provider.Service : the Service to add |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method denies
access to set property values. |
NullPointerException |
if s is null |
removeService
protected void removeService (Provider.Service s)
Remove a service previously added using
putService()
. The specified service is removed from
this provider. It will no longer be returned by
getService()
and its information will be removed
from this provider's Hashtable.
Also, if there is a security manager, its
checkSecurityAccess
method is called with the string
"removeProviderProperty."+name
, where name
is
the provider name, to see if it's ok to remove this provider's
properties. If the default implementation of
checkSecurityAccess
is used (that is, that method is not
overriden), then this results in a call to the security manager's
checkPermission
method with a
SecurityPermission("removeProviderProperty."+name)
permission.
Parameters | |
---|---|
s |
Provider.Service : the Service to be removed |
Throws | |
---|---|
SecurityException |
if a security manager exists and its SecurityManager.checkSecurityAccess(String) method denies
access to remove this provider's properties. |
NullPointerException |
if s is null |
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Last updated 2024-06-18 UTC.