The description of a security service. It encapsulates the properties of a service and contains a factory method to obtain new implementation instances of this service.
Each service has a provider that offers the service, a type, an algorithm name, and the name of the class that implements the service. Optionally, it also includes a list of alternate algorithm names for this service (aliases) and attributes, which are a map of (name, value) String pairs.
This class defines the methods supportsParameter()
and newInstance()
which are used by the Java security framework when it searches for
suitable services and instantiates them. The valid arguments to those
methods depend on the type of service. For the service types defined
within Java SE, see the
Java Cryptography Architecture API Specification & Reference
for the valid values.
Note that components outside of Java SE can define additional types of
services and their behavior.
Instances of this class are immutable.
Public Constructor Summary
Public Method Summary
final String |
getAlgorithm()
Return the name of the algorithm of this service.
|
final String |
getAttribute(String name)
Return the value of the specified attribute or null if this
attribute is not set for this Service.
|
final String |
getClassName()
Return the name of the class implementing this service.
|
final Provider |
getProvider()
Return the Provider of this service.
|
final String |
getType()
Get the type of this service.
|
Object |
newInstance(Object constructorParameter)
Return a new instance of the implementation described by this
service.
|
boolean | |
String |
toString()
Return a String representation of this service.
|
Inherited Method Summary
Public Constructors
public Service (Provider provider, String type, String algorithm, String className, List<String> aliases, Map<String, String> attributes)
Construct a new service.
Parameters
provider | the provider that offers this service |
---|---|
type | the type of this service |
algorithm | the algorithm name |
className | the name of the class implementing this service |
aliases | List of aliases or null if algorithm has no aliases |
attributes | Map of attributes or null if this implementation has no attributes |
Throws
NullPointerException | if provider, type, algorithm, or className is null |
---|
Public Methods
public final String getAlgorithm ()
Return the name of the algorithm of this service. For example,
SHA-1
.
Returns
- the algorithm of this service
public final String getAttribute (String name)
Return the value of the specified attribute or null if this attribute is not set for this Service.
Parameters
name | the name of the requested attribute |
---|
Returns
- the value of the specified attribute or null if the attribute is not present
Throws
NullPointerException | if name is null |
---|
public final String getClassName ()
Return the name of the class implementing this service.
Returns
- the name of the class implementing this service
public final Provider getProvider ()
Return the Provider of this service.
Returns
- the Provider of this service
public final String getType ()
Get the type of this service. For example, MessageDigest
.
Returns
- the type of this service
public Object newInstance (Object constructorParameter)
Return a new instance of the implementation described by this service. The security provider framework uses this method to construct implementations. Applications will typically not need to call it.
The default implementation uses reflection to invoke the standard constructor for this type of service. Security providers can override this method to implement instantiation in a different way. For details and the values of constructorParameter that are valid for the various types of services see the Java Cryptography Architecture API Specification & Reference.
Parameters
constructorParameter | the value to pass to the constructor, or null if this type of service does not use a constructorParameter. |
---|
Returns
- a new implementation of this service
Throws
InvalidParameterException | if the value of constructorParameter is invalid for this type of service. |
---|---|
NoSuchAlgorithmException | if instantiation failed for any other reason. |
public boolean supportsParameter (Object parameter)
Test whether this Service can use the specified parameter. Returns false if this service cannot use the parameter. Returns true if this service can use the parameter, if a fast test is infeasible, or if the status is unknown.
The security provider framework uses this method with some types of services to quickly exclude non-matching implementations for consideration. Applications will typically not need to call it.
For details and the values of parameter that are valid for the various types of services see the top of this class and the Java Cryptography Architecture API Specification & Reference. Security providers can override it to implement their own test.
Parameters
parameter | the parameter to test |
---|
Returns
- false if this this service cannot use the specified parameter; true if it can possibly use the parameter
Throws
InvalidParameterException | if the value of parameter is invalid for this type of service or if this method cannot be used with this type of service |
---|
public String toString ()
Return a String representation of this service.
Returns
- a String representation of this service.