* Providers are installed by name and version number. See the static
* initializer of the {@link java.security.Security} class for the default
* security providers installed by this class library.
*
* @author Aaron M. Renn (arenn@urbanophile.com)
*/
public abstract class Provider
extends Properties
implements Serializable
{
private static final long serialVersionUID = -4298000515446427739L;
/**
* This is a textual description of the provider
*/
private String info;
/**
* This is the name of the provider
*/
private String name;
/**
* This is the version number of the provider
*/
private double version;
/**
* This method initializes a new instance of Provider to have
* the specified name, version, and description information.
*
* @param name The name to assign to this Provider.
* @param version The version number for this Provider.
* @param info A textual description of this provider.
*/
protected Provider(String name, double version, String info)
{
this.name = name;
this.version = version;
this.info = info;
}
/**
* This method returns the name assigned to this Provider.
*
* @return The Provider's name.
*/
public String getName()
{
return (name);
}
/**
* This method retunrs the version number of this Provider.
*
* @return The Provider's version number.
*/
public double getVersion()
{
return (version);
}
/**
* This method returns a textual description of the Provider.
*
* @return A description of the Provider.
*/
public String getInfo()
{
return (info);
}
/**
* Maps a key property to a designated value.
*
* If there is an installed {@link SecurityManager} object in the underlying
* VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
* called with the string "putProviderProperty." + name, where
* name is this provider's name. For the default implementation
* this translates into a {@link SecurityManager#checkPermission(Permission)}
* for a SecurityPermission("putProviderProperty." + name).
*
* @param key The property key.
* @param value The property value.
* @return The previous value of the specified property (key),
* or null if it did not have one.
* @throws SecurityException If a security manager is installed and its
* {@link SecurityManager#checkSecurityAccess(String)} method
* disallows adding properties at run-time.
* @since Classpath 0.4+cvs, JDK 1.2
* @see java.lang.Object#equals(Object)
* @see java.util.Hashtable#get(Object)
*/
public Object put(Object key, Object value)
{
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkSecurityAccess("putProviderProperty." + this.name);
return super.put(toCanonicalKey(key), value);
}
// overrides same in java.util.Hashtable
public Object get(Object key)
{
return super.get(toCanonicalKey(key));
}
/**
* This method removes the specified key entry (and its associated value)
* from the property mapping collection.
*
* If there is an installed {@link SecurityManager} object in the underlying
* VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
* called with the string "removeProviderProperty." + name, where
* name is this provider's name. For the default implementation
* this translates into a {@link SecurityManager#checkPermission(Permission)}
* for a SecurityPermission("removeProviderProperty." + name).
*
* @param key The key to remove
* @return The previous value for this key, or null if no
* previous value.
*/
public Object remove(Object key)
{
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkSecurityAccess("removeProviderProperty." + this.name);
return super.remove(toCanonicalKey(key));
}
/**
* This method clears the entire property collection such that it no longer
* contains the properties used to look up the services provided by
* this Provider.
*
* If there is an installed {@link SecurityManager} object in the underlying
* VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
* called with the string "clearProviderProperties." + name,
* where name is this provider's name. For the default
* implementation this translates into a
* {@link SecurityManager#checkPermission(Permission)} for a
* SecurityPermission("clearProviderProperties." + name).
*/
public void clear()
{
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkSecurityAccess("clearProviderProperties." + this.name);
super.clear();
}
/**
* This method returns a String representation of this
* object. This will include the Provider name and
* version number.
*
* @return A String representation of this object.
*/
public String toString()
{
return (getClass().getName() + ": name=" + getName() + " version=" +
version);
}
private Object toCanonicalKey(Object key)
{
if (key.getClass().isAssignableFrom(String.class)) // is it ours?
return ((String) key).toUpperCase(); // use default locale
return key;
}
}