subject.java

gcc的组建

          {
            result.add(o);
          }
      }
    return Collections.unmodifiableSet (result);
  }

  public Set getPrivateCredentials()
  {
    return privCred;
  }

  public Set getPrivateCredentials (Class clazz)
  {
    HashSet result = new HashSet (privCred.size());
    for (Iterator it = privCred.iterator(); it.hasNext(); )
      {
        Object o = it.next();
        if (o != null && clazz.isAssignableFrom (o.getClass()))
          {
            result.add(o);
          }
      }
    return Collections.unmodifiableSet (result);
  }

  public Set getPublicCredentials()
  {
    return pubCred;
  }

  public Set getPublicCredentials (Class clazz)
  {
    HashSet result = new HashSet (pubCred.size());
    for (Iterator it = pubCred.iterator(); it.hasNext(); )
      {
        Object o = it.next();
        if (o != null && clazz.isAssignableFrom (o.getClass()))
          {
            result.add(o);
          }
      }
    return Collections.unmodifiableSet (result);
  }

  public int hashCode()
  {
    return principals.hashCode() + privCred.hashCode() + pubCred.hashCode();
  }

  /**
   * <p>Returns whether or not this subject is read-only.</p>
   *
   * @return True is this subject is read-only.
   */
  public boolean isReadOnly()
  {
    return readOnly;
  }

  /**
   * <p>Marks this subject as read-only.</p>
   *
   * @throws SecurityException If the caller does not have permission to
   *  set this subject as read-only (<code>"setReadOnly"</code> target of
   *  {@link AuthPermission}.
   */
  public void setReadOnly()
  {
    final SecurityManager sm = System.getSecurityManager();
    if (sm != null)
      {
        sm.checkPermission (new AuthPermission ("setReadOnly"));
      }
    readOnly = true;
  }

  public String toString()
  {
    return Subject.class.getName() + " [ principals=" + principals +
      ", private credentials=" + privCred + ", public credentials=" +
      pubCred + ", read-only=" + readOnly + " ]";
  }

// Inner class.
  // -------------------------------------------------------------------------

  /**
   * An undocumented inner class that is used for sets in the parent class.
   */
  private static class SecureSet extends AbstractSet implements Serializable
  {
    // Fields.
    // -----------------------------------------------------------------------

    private static final long serialVersionUID = 7911754171111800359L;

    static final int PRINCIPALS = 0;
    static final int PUBLIC_CREDENTIALS = 1;
    static final int PRIVATE_CREDENTIALS = 2;

    private final Subject subject;
    private final LinkedList elements;
    private final transient int type;

    // Constructors.
    // -----------------------------------------------------------------------

    SecureSet (final Subject subject, final int type, final Collection inElements)
    {
      this (subject, type);
      for (Iterator it = inElements.iterator(); it.hasNext(); )
        {
          Object o = it.next();
          if (type == PRINCIPALS && !(o instanceof Principal))
            {
              throw new IllegalArgumentException(o+" is not a Principal");
            }
          if (!this.elements.contains (o))
            {
              this.elements.add (o);
            }
        }
    }

    SecureSet (final Subject subject, final int type)
    {
      this.subject = subject;
      this.type = type;
      this.elements = new LinkedList();
    }

    // Instance methods.
    // -----------------------------------------------------------------------

    public synchronized int size()
    {
      return elements.size();
    }

    public Iterator iterator()
    {
      return elements.iterator();
    }

    public synchronized boolean add(Object element)
    {
      if (subject.isReadOnly())
        {
          throw new IllegalStateException ("subject is read-only");
        }
      final SecurityManager sm = System.getSecurityManager();
      switch (type)
        {
        case PRINCIPALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPrincipals"));
            }
          if (!(element instanceof Principal))
            {
              throw new IllegalArgumentException ("element is not a Principal");
            }
          break;

        case PUBLIC_CREDENTIALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPublicCredentials"));
            }
          break;

        case PRIVATE_CREDENTIALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPrivateCredentials"));
            }
          break;

        default:
          throw new Error ("this statement should be unreachable");
        }

      if (elements.contains (element))
        {
          return false;
        }

      return elements.add (element);
    }

    public synchronized boolean remove (final Object element)
    {
      if (subject.isReadOnly())
        {
          throw new IllegalStateException ("subject is read-only");
        }
      final SecurityManager sm = System.getSecurityManager();
      switch (type)
        {
        case PRINCIPALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPrincipals"));
            }
          if (!(element instanceof Principal))
            {
              throw new IllegalArgumentException ("element is not a Principal");
            }
          break;

        case PUBLIC_CREDENTIALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPublicCredentials"));
            }
          break;

        case PRIVATE_CREDENTIALS:
          if (sm != null)
            {
              sm.checkPermission (new AuthPermission ("modifyPrivateCredentials"));
            }
          break;

        default:
          throw new Error("this statement should be unreachable");
        }

      return elements.remove(element);
    }

    public synchronized boolean contains (final Object element)
    {
      return elements.contains (element);
    }

    public boolean removeAll (final Collection c)
    {
      if (subject.isReadOnly())
        {
          throw new IllegalStateException ("subject is read-only");
        }
      return super.removeAll (c);
    }

    public boolean retainAll (final Collection c)
    {
      if (subject.isReadOnly())
        {
          throw new IllegalStateException ("subject is read-only");
        }
      return super.retainAll (c);
    }

    public void clear()
    {
      if (subject.isReadOnly())
        {
          throw new IllegalStateException ("subject is read-only");
        }
      elements.clear();
    }

    private synchronized void writeObject (ObjectOutputStream out)
      throws IOException
    {
      throw new UnsupportedOperationException ("FIXME: determine serialization");
    }

    private void readObject (ObjectInputStream in)
      throws ClassNotFoundException, IOException
    {
      throw new UnsupportedOperationException ("FIXME: determine serialization");
    }
  }
}