javax.microedition.io

Class MulticastProtocolPermission

java.lang.Object

java.security.Permission

javax.microedition.io.GCFPermission

javax.microedition.io.MulticastProtocolPermission

public final class MulticastProtocolPermission
extends GCFPermission

This class represents access rights to connections via the "multicast" protocol. A MulticastProtocolPermission consists of a URI string but no actions list.

The URI string specifies a connection for sending and receiving multicast datagrams. It takes the following general form:

 multicast://{host}:{portspec}
 

The exact syntax for the MulticastProtocolPermission URI is provided by the BNF rule multicast_permission. The value of the {host} field must be a symbolic hostname, a literal IPv4 multicast address or a literal IPv6 address surrounded by square brackets ("[", "]"), as specified by RFC 3986. The hostspec may be "*" to allow connection to any multicast host group.

The {hostspec} field is omitted to indicate an inbound, "server mode" connection.

Server-mode URIs may also omit the <portspec> field to request a system-assigned port number. In such a case, the MulticastProtocolPermission is normalized to the equivalent URI "multicast://:1024-65535".

The <portspec> string takes the following form:

 portnumber | -portnumber | portnumber-[portnumber] | "*"
 

A <portspec> specification of the form "N-" (where N is a port number) signifies all ports numbered N and above, while a specification of the form "-N" indicates all ports numbered N and below. A single asterisk in the place of the <portspec> field matches all ports. Therefore, the URI "multicast://<ipaddr>:*" matches multicast a host group to all ports, and the URI "multicast://*:*" matches multicast connections to all host groups on all ports.

See Also:

UDPMulticastConnection, Connector.open(java.lang.String)

Constructor Summary

Constructors

Constructor and Description
MulticastProtocolPermission(java.lang.String uri) Creates a new MulticastProtocolPermission with the specified URI as its name.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj) Checks two MulticastProtocolPermission objects for equality.
java.lang.String	getActions() Returns the canonical string representation of the actions, which currently is the empty string "", since there are no actions defined for MulticastProtocolPermission.
int	hashCode() Returns the hash code value for this object.
boolean	implies(java.security.Permission p) Checks if this MulticastProtocolPermission object "implies" the specified permission.
java.security.PermissionCollection	newPermissionCollection() Returns a new PermissionCollection for storing MulticastProtocolPermission objects.

Methods inherited from class javax.microedition.io.GCFPermission

getProtocol, getURI

Methods inherited from class java.security.Permission

getName, toString

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MulticastProtocolPermission

public MulticastProtocolPermission(java.lang.String uri)

Creates a new MulticastProtocolPermission with the specified URI as its name. The URI string must conform to the specification given above, and is normalized to facilitate subsequent comparisons.

Parameters:

uri - the URI string.

Throws:

java.lang.IllegalArgumentException - if uri is malformed.

java.lang.NullPointerException - if uri is null.

See Also:

Permission.getName()

Method Detail

equals

public boolean equals(java.lang.Object obj)

Checks two MulticastProtocolPermission objects for equality.

Specified by:

equals in class java.security.Permission

Parameters:

obj - the object we are testing for equality with this object.

Returns:

true if obj is a MulticastProtocolPermission and has the same URI string as this MulticastProtocolPermission object.

See Also:

Object.hashCode(), HashMap

getActions

public java.lang.String getActions()

Returns the canonical string representation of the actions, which currently is the empty string "", since there are no actions defined for MulticastProtocolPermission.

Specified by:

getActions in class java.security.Permission

Returns:

the empty string "".

hashCode

public int hashCode()

Returns the hash code value for this object.

Specified by:

hashCode in class java.security.Permission

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

implies

public boolean implies(java.security.Permission p)

Checks if this MulticastProtocolPermission object "implies" the specified permission.

To determine whether this object implies another permission, p, this method first ensures that all of the following are true (and returns false if any of them are not):

• p is an instanceof MulticastProtocolPermission, and
• p's port range is included in this port range.

Then implies checks each of the following, in order, and for each returns true if the stated condition is true:

• If this object has a single multicast IP address and p's IP address is equal to this object's multicast IP address.
• If this object has a wildcard ("*"), or p's ipaddr is equal to this object's ipaddr.

If none of the above are true, implies returns false.

Specified by:

implies in class java.security.Permission

Parameters:

p - the permission to check against.

Returns:

true if the specified permission is implied by this object, false if not.

newPermissionCollection

public java.security.PermissionCollection newPermissionCollection()

Returns a new PermissionCollection for storing MulticastProtocolPermission objects.

MulticastProtocolPermission objects must be stored in a manner that allows them to be inserted into the collection in any order, but that also enables the PermissionCollection implies method to be implemented in an efficient (and consistent) manner.

If null is returned, then the caller of this method is free to store permissions of this type in any PermissionCollection they choose (one that uses a Hashtable, one that uses a Vector, etc).

Overrides:

newPermissionCollection in class java.security.Permission

Returns:

a new PermissionCollection suitable for storing MulticastProtocolPermission objects, or null if one is not defined.