org.apache.harmony.security.fortress

Class Engine

java.lang.Object

org.apache.harmony.security.fortress.Engine

public final class Engine
extends Object

This class implements common functionality for Provider supplied classes. The usage pattern is to allocate static Engine instance per service type and synchronize on that instance during calls to getInstance and retrieval of the selected Provider and Service Provider Interface (SPI) results. Retrieving the results with getProvider and getSpi sets the internal Engine values to null to prevent memory leaks.

For example:

   
   public class Foo {

       private static final Engine ENGINE = new Engine("Foo");

       private final FooSpi spi;
       private final Provider provider;
       private final String algorithm;

       protected Foo(FooSpi spi,
                     Provider provider,
                     String algorithm) {
           this.spi = spi;
           this.provider = provider;
           this.algorithm = algorithm;
       }

       public static Foo getInstance(String algorithm) {
           Engine.SpiAndProvider sap = ENGINE.getInstance(algorithm, null);
           return new Foo((FooSpi) sap.spi, sap.provider, algorithm);
       }

       public static Foo getInstance(String algorithm, Provider provider) {
           Object spi = ENGINE.getInstance(algorithm, provider, null);
           return new Foo((FooSpi) spi, provider, algorithm);
       }

       ...

 }

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Engine.SpiAndProvider

Field Summary

Fields

Modifier and Type	Field and Description
static SecurityAccess	door Access to package visible api in java.security

Constructor Summary

Constructors

Constructor and Description
Engine(String serviceName) Creates a Engine object

Method Summary

Modifier and Type	Method and Description
Engine.SpiAndProvider	getInstance(Provider.Service service, String param) Finds the appropriate service implementation and returns an SpiAndProvider instance containing a reference to SPI and its Provider
Engine.SpiAndProvider	getInstance(String algorithm, Object param) Finds the appropriate service implementation and returns an SpiAndProvider instance containing a reference to the first matching SPI and its Provider
Object	getInstance(String algorithm, Provider provider, Object param) Finds the appropriate service implementation and returns and instance of the class that implements corresponding Service Provider Interface.
ArrayList<Provider.Service>	getServices() Returns a list of all providers for this type of service or null if no matches were found.
ArrayList<Provider.Service>	getServices(String algorithm) Returns a list of all possible matches for a given algorithm.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

door

public static SecurityAccess door

Access to package visible api in java.security

Constructor Detail

Engine

public Engine(String serviceName)

Creates a Engine object

Parameters:

serviceName -

Method Detail

getInstance

public Engine.SpiAndProvider getInstance(String algorithm,
                                         Object param)
                                  throws NoSuchAlgorithmException

Finds the appropriate service implementation and returns an SpiAndProvider instance containing a reference to the first matching SPI and its Provider

Throws:

NoSuchAlgorithmException

getInstance

public Engine.SpiAndProvider getInstance(Provider.Service service,
                                         String param)
                                  throws NoSuchAlgorithmException

Finds the appropriate service implementation and returns an SpiAndProvider instance containing a reference to SPI and its Provider

Throws:

NoSuchAlgorithmException

getServices

public ArrayList<Provider.Service> getServices()

Returns a list of all providers for this type of service or null if no matches were found.

getServices

public ArrayList<Provider.Service> getServices(String algorithm)

Returns a list of all possible matches for a given algorithm. Returns null if no matches were found.

getInstance

public Object getInstance(String algorithm,
                          Provider provider,
                          Object param)
                   throws NoSuchAlgorithmException

Finds the appropriate service implementation and returns and instance of the class that implements corresponding Service Provider Interface.

Throws:

NoSuchAlgorithmException