Class Provider

All Implemented Interfaces:
Serializable, Cloneable, Map<Object,Object>
Direct Known Subclasses:
AuthProvider

public abstract class Provider
extends Properties

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()
See Also:
Serialized Form

Nested Classes

Modifier and Type Class and Description
static class  Provider.Service

The description of a security service.

Fields

Fields inherited from class java.util.Properties

defaults

Constructors

Modifier Constructor and Description
protected Provider(String name, double version, String info)

Constructs a provider with the specified name, version number, and information.

Methods

Modifier and Type Method and Description
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,? extends Object> remappingFunction)

Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).
Object computeIfAbsent(Object key, Function<? super Object,? extends 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.
Object computeIfPresent(Object key, BiFunction<? super Object,? super Object,? extends 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<Map.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 null if this map contains no mapping for the key.
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 defaultValue if this map contains no mapping for the key.
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.
Enumeration<Object> keys()

Returns an enumeration of the keys in this hashtable.
Set<Object> keySet()

Returns an unmodifiable Set view of the property keys contained in this provider.
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,? extends 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 key property to have the specified value.
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 null) associates it with the given value and returns null, else returns the current value.
protected void putService(Provider.Service s)

Add a service.
Object remove(Object key)

Removes the key property (and its corresponding value).
boolean remove(Object key, Object value)

Removes the entry for the specified key only if it is currently mapped to the specified value.
protected void removeService(Provider.Service s)

Remove a service previously added using putService().
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,? extends 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.

Methods inherited from class java.util.Properties

getProperty, list, list, load, loadFromXML, propertyNames, save, setProperty, store, store, storeToXML, storeToXML, stringPropertyNames

Methods inherited from class java.util.Hashtable

clone, contains, containsKey, containsValue, equals, hashCode, isEmpty, rehash, size

Methods inherited from class java.lang.Object

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

Constructors

Provider

protected Provider(String name,
                   double version,
                   String info)

Constructs a provider with the specified name, version number, and information.

Parameters:
name - the provider name.
version - the provider version number.
info - a description of the provider and its services.

Methods

getName

public String getName()

Returns the name of this provider.

Returns:
the name of this provider.

getVersion

public double getVersion()

Returns the version number for this provider.

Returns:
the version number for this provider.

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:
a description of the provider and its services.

toString

public String toString()

Returns a string with the name and the version number of this provider.

Overrides:
toString in class Hashtable<Object,Object>
Returns:
the string with the name and the version number for this provider.

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.

Specified by:
clear in interface Map<Object,Object>
Overrides:
clear in class Hashtable<Object,Object>
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to clear this provider
Since:
1.2

load

public void load(InputStream inStream)
          throws IOException

Reads a property list (key and element pairs) from the input stream.

Overrides:
load in class Properties
Parameters:
inStream - the input stream.
Throws:
IOException - if an error occurred when reading from the input stream.
See Also:
Properties.load(java.io.Reader)

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.

Specified by:
putAll in interface Map<Object,Object>
Overrides:
putAll in class Hashtable<Object,Object>
Parameters:
t - mappings to be stored in this map
Since:
1.2

entrySet

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

Returns an unmodifiable Set view of the property entries contained in this Provider.

Specified by:
entrySet in interface Map<Object,Object>
Overrides:
entrySet in class Hashtable<Object,Object>
Returns:
a set view of the mappings contained in this map
Since:
1.2
See Also:
Map.Entry

keySet

public Set<Object> keySet()

Returns an unmodifiable Set view of the property keys contained in this provider.

Specified by:
keySet in interface Map<Object,Object>
Overrides:
keySet in class Hashtable<Object,Object>
Returns:
a set view of the keys contained in this map
Since:
1.2

values

public Collection<Object> values()

Returns an unmodifiable Collection view of the property values contained in this provider.

Specified by:
values in interface Map<Object,Object>
Overrides:
values in class Hashtable<Object,Object>
Returns:
a collection view of the values contained in this map
Since:
1.2

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.

Specified by:
put in interface Map<Object,Object>
Overrides:
put in class Hashtable<Object,Object>
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:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values.
Since:
1.2
See Also:
Object.equals(Object), Hashtable.get(Object)

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.

Specified by:
putIfAbsent in interface Map<Object,Object>
Overrides:
putIfAbsent in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is to be associated
value - value to be associated with the specified key
Returns:
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(java.lang.String) method denies access to set property values.
Since:
1.8

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.

Specified by:
remove in interface Map<Object,Object>
Overrides:
remove in class Hashtable<Object,Object>
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:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to remove this provider's properties.
Since:
1.2

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.

Specified by:
remove in interface Map<Object,Object>
Overrides:
remove in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is associated
value - value expected to be associated with the specified key
Returns:
true if the value was removed
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to remove this provider's properties.
Since:
1.8

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.

Specified by:
replace in interface Map<Object,Object>
Overrides:
replace in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is associated
oldValue - value expected to be associated with the specified key
newValue - value to be associated with the specified key
Returns:
true if the value was replaced
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values.
Since:
1.8

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.

Specified by:
replace in interface Map<Object,Object>
Overrides:
replace in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is associated
value - value to be associated with the specified key
Returns:
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(java.lang.String) method denies access to set property values.
Since:
1.8

replaceAll

public void replaceAll(BiFunction<? super Object,? super Object,? extends 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.

Specified by:
replaceAll in interface Map<Object,Object>
Overrides:
replaceAll in class Hashtable<Object,Object>
Parameters:
function - the function to apply to each entry
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values.
Since:
1.8

compute

public Object compute(Object key,
                      BiFunction<? super Object,? super Object,? extends 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.

Specified by:
compute in interface Map<Object,Object>
Overrides:
compute in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is to be associated
remappingFunction - the function to compute a value
Returns:
the new value associated with the specified key, or null if none
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values or remove properties.
Since:
1.8

computeIfAbsent

public Object computeIfAbsent(Object key,
                              Function<? super Object,? extends 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.

Specified by:
computeIfAbsent in interface Map<Object,Object>
Overrides:
computeIfAbsent in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is to be associated
mappingFunction - the function to compute a value
Returns:
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(java.lang.String) method denies access to set property values and remove properties.
Since:
1.8

computeIfPresent

public Object computeIfPresent(Object key,
                               BiFunction<? super Object,? super Object,? extends 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.

Specified by:
computeIfPresent in interface Map<Object,Object>
Overrides:
computeIfPresent in class Hashtable<Object,Object>
Parameters:
key - key with which the specified value is to be associated
remappingFunction - the function to compute a value
Returns:
the new value associated with the specified key, or null if none
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values or remove properties.
Since:
1.8

merge

public Object merge(Object key,
                    Object value,
                    BiFunction<? super Object,? super Object,? extends 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.

Specified by:
merge in interface Map<Object,Object>
Overrides:
merge in class Hashtable<Object,Object>
Parameters:
key - key with which the resulting value is to be associated
value - 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 - the function to recompute a value if present
Returns:
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(java.lang.String) method denies access to set property values or remove properties.
Since:
1.8

get

public Object get(Object key)

Description copied from class: Hashtable

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.)

Specified by:
get in interface Map<Object,Object>
Overrides:
get in class Hashtable<Object,Object>
Parameters:
key - the key whose associated value is to be returned
Returns:
the value to which the specified key is mapped, or null if this map contains no mapping for the key
See Also:
Hashtable.put(Object, Object)

getOrDefault

public Object getOrDefault(Object key,
                           Object defaultValue)

Description copied from interface: Map

Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.

Specified by:
getOrDefault in interface Map<Object,Object>
Overrides:
getOrDefault in class Hashtable<Object,Object>
Parameters:
key - the key whose associated value is to be returned
defaultValue - the default mapping of the key
Returns:
the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key
Since:
1.8

forEach

public void forEach(BiConsumer<? super Object,? super Object> action)

Description copied from interface: Map

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.

Specified by:
forEach in interface Map<Object,Object>
Overrides:
forEach in class Hashtable<Object,Object>
Parameters:
action - The action to be performed for each entry
Since:
1.8

keys

public Enumeration<Object> keys()

Description copied from class: Hashtable

Returns an enumeration of the keys in this hashtable.

Overrides:
keys in class Hashtable<Object,Object>
Returns:
an enumeration of the keys in this hashtable.
See Also:
Enumeration, Hashtable.elements(), Hashtable.keySet(), Map

elements

public Enumeration<Object> elements()

Description copied from class: Hashtable

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

Overrides:
elements in class Hashtable<Object,Object>
Returns:
an enumeration of the values in this hashtable.
See Also:
Enumeration, Hashtable.keys(), Hashtable.values(), Map

getProperty

public String getProperty(String key)

Description copied from class: Properties

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.

Overrides:
getProperty in class Properties
Parameters:
key - the property key.
Returns:
the value in this property list with the specified key value.
See Also:
Properties.setProperty(java.lang.String, java.lang.String), Properties.defaults

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 - the type of service requested (for example, MessageDigest)
algorithm - the case insensitive algorithm name (or alternate alias) of the service requested (for example, SHA-1)
Returns:
the service describing this Provider's matching service or null if no such service exists
Throws:
NullPointerException - if type or algorithm is null
Since:
1.5

getServices

public Set<Provider.Service> getServices()

Get an unmodifiable Set of all services supported by this Provider.

Returns:
an unmodifiable Set of all services supported by this Provider
Since:
1.5

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 - the Service to add
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to set property values.
NullPointerException - if s is null
Since:
1.5

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 - the Service to be removed
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkSecurityAccess(java.lang.String) method denies access to remove this provider's properties.
NullPointerException - if s is null
Since:
1.5

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https://docs.oracle.com/javase/8/docs/api/java/security/Provider.html