Serializable, Guard
public final class SocketPermission extends Permission implements Serializable
host = (hostname | IPv4address | iPv6reference) [:portrange]
portrange = portnumber | -portnumber | portnumber-[portnumber]
The host is expressed as a DNS name, as a numerical IP address, or as "localhost" (for the local machine). The wildcard "*" may be included once in a DNS name host specification. If it is included, it must be in the leftmost position, as in "*.example.com". The format of the IPv6reference should follow that specified in RFC 2732: Format for Literal IPv6 Addresses in URLs:
ipv6reference = "[" IPv6address "]"
For example, you can construct a SocketPermission instance as the following:
String hostAddress = inetaddress.getHostAddress();
if (inetaddress instanceof Inet6Address) {
sp = new SocketPermission("[" + hostAddress + "]:" + port, action);
} else {
sp = new SocketPermission(hostAddress + ":" + port, action);
}
or
String host = url.getHost();
sp = new SocketPermission(host + ":" + port, action);
The full uncompressed form of an IPv6 literal address is also valid.
The port or portrange is optional. A port 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. The special port value 0 refers to the entire ephemeral port range. This is a fixed range of ports a system may use to allocate dynamic ports from. The actual range may be system dependent.
The possible ways to connect to the host are
accept connect listen resolveThe "listen" action is only meaningful when used with "localhost" and means the ability to bind to a specified port. The "resolve" action is implied when any of the other actions are present. The action "resolve" refers to host/ip name service lookups.
The actions string is converted to lowercase before processing.
As an example of the creation and meaning of SocketPermissions, note that if the following permission:
p1 = new SocketPermission("foo.example.com:7777", "connect,accept");
is granted to some code, it allows that code to connect to port 7777 on foo.example.com, and to accept connections on that port. Similarly, if the following permission:
p2 = new SocketPermission("localhost:1024-", "accept,connect,listen");
is granted to some code, it allows that code to accept connections on, connect to, or listen on any port between 1024 and 65535 on the local host. Note: Granting code permission to accept or make connections to remote hosts may be dangerous because malevolent code can then more easily transfer and share confidential data among parties who may not otherwise have access to the data.
| Constructor | Description |
|---|---|
SocketPermission |
Creates a new SocketPermission object with the specified actions. |
| Modifier and Type | Method | Description |
|---|---|---|
boolean |
equals |
Checks two SocketPermission objects for equality. |
String |
getActions() |
Returns the canonical string representation of the actions. |
int |
hashCode() |
Returns the hash code value for this object. |
boolean |
implies |
Checks if this socket permission object "implies" the specified permission. |
PermissionCollection |
newPermissionCollection() |
Returns a new PermissionCollection object for storing SocketPermission objects. |
checkGuard, getName, toString
public SocketPermission(String host, String action)
To specify the local machine, use "localhost" as the host. Also note: An empty host String ("") is equivalent to "localhost".
The actions parameter contains a comma-separated list of the actions granted for the specified host (and port(s)). Possible actions are "connect", "listen", "accept", "resolve", or any combination of those. "resolve" is automatically added when any of the other three are specified.
Examples of SocketPermission instantiation are the following:
nr = new SocketPermission("www.example.com", "connect");
nr = new SocketPermission("www.example.com:80", "connect");
nr = new SocketPermission("*.example.com", "connect");
nr = new SocketPermission("*.edu", "resolve");
nr = new SocketPermission("204.160.241.0", "connect");
nr = new SocketPermission("localhost:1024-65535", "listen");
nr = new SocketPermission("204.160.241.0:1024-65535", "connect");
host - the hostname or IP address of the computer, optionally including a colon followed by a port or port range.action - the action string.NullPointerException - if any parameters are nullIllegalArgumentException - if the format of host is invalid, or if the action string is empty, malformed, or contains an action other than the specified possible actionspublic boolean implies(Permission p)
More specifically, this method first ensures that all of the following are true (and returns false if any of them are not):
implies checks each of the following, in order, and for each returns true if the stated condition is true: implies returns false.implies in class Permission
p - the permission to check against.public boolean equals(Object obj)
equals in class Permission
obj - the object to test for equality with this object.public int hashCode()
hashCode in class Permission
public String getActions()
getActions in class Permission
public PermissionCollection newPermissionCollection()
SocketPermission 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.
newPermissionCollection in class Permission
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/net/SocketPermission.html