This class represents a security provider. It specifies class names for implementations of one or more algorithms for message digests, digital signatures, key generation, key conversion, key management, secure random number generation, certificate conversion, and algorithm parameter management. The getName( ), getVersion( ), and getInfo( ) methods return information about the provider. Provider inherits from Properties and maintains a mapping of property names to property values. These name/value pairs specify the capabilities of the Provider implementation. Each property name has the form:

service_type.algorithm_name

The corresponding property value is the name of the class that implements the named algorithm. For example, say a Provider defines properties named "Signature.DSA", "MessageDigest.MD5", and "KeyStore.JKS". The values of these properties are the class names of SignatureSpi, MessageDigestSpi, and KeyStoreSpi implementations. Other properties defined by a Provider are used to provide aliases for algorithm names. For example, the property Alg.Alias.MessageDigest.SHA1 might have the value "SHA", meaning that the algorithm name "SHA1" is an alias for "SHA".

In Java 5.0, the individual services provided by a Provider are described by the nested Service class, and various methods for querying and setting the Service objects of a Provider are available.

Security providers are installed in an implementation-dependent way. For Sun's implementation, the ${java.home}/lib/security/java.security file specifies the class names of all installed Provider implementations. An application can also install its own custom Provider with the addProvider( ) and insertProviderAt( ) methods of the Security class. Most applications do not need to use the Provider class directly. Typically, only security-provider implementors need to use the Provider class. Some applications may explicitly specify the name of a desired Provider when calling a static getInstance( ) factory method, however. Only applications with the most demanding cryptographic needs require custom providers.

Figure 14-32. java.security.Provider

public abstract class Provider extends java.util.Properties {
// Protected Constructors
     protected Provider(String name, double version, String info);  
// Nested Types
5.0  public static class Service; 
// Public Instance Methods
     public String getInfo( );  
     public String getName( );  
5.0  public Provider.Service getService(String type, 
        String algorithm);     synchronized
5.0  public java.util.Set<Provider.Service> getServices( );     synchronized
     public double getVersion( );  
// Public Methods Overriding Properties
1.2  public void load(java.io.InputStream inStream) throws java.io.IOException;     synchronized
// Public Methods Overriding Hashtable
1.2  public void clear( );     synchronized
1.2  public java.util.Set<java.util.Map.Entry<Object,
        Object>> entrySet( );     synchronized
1.2  public java.util.Set<Object> keySet( );  
1.2  public Object put(Object key, Object value);       synchronized
1.2  public void putAll(java.util.Map<?,?> t);              synchronized
1.2  public Object remove(Object key);              synchronized
     public String toString( );  
1.2  public java.util.Collection<Object> values( );  
// Protected Instance Methods
5.0  protected void putService(Provider.Service s);        synchronized
5.0  protected void removeService(Provider.Service s);      synchronized
}

Subclasses

AuthProvider

Passed To

Too many methods to list.

Returned By

Too many methods to list.