LinkPermission

AI-generated Key Takeaways

LinkPermission controls the creation of hard links and symbolic links in Java.
It has two target permission names: "hard" for creating hard links and "symbolic" for creating symbolic links.
Granting this permission is risky as it could allow unauthorized access to the file system.
LinkPermission inherits methods from BasicPermission, Permission, Object, and Guard for permission management and security checks.
Two constructors allow creating a LinkPermission with just a name or with a name and actions (which should be empty or null).

public final class LinkPermission extends BasicPermission

The Permission class for link creation operations.

The following table provides a summary description of what the permission allows, and discusses the risks of granting code the permission.

Permission Target Name	What the Permission Allows	Risks of Allowing this Permission
hard	Ability to add an existing file to a directory. This is sometimes known as creating a link, or hard link.	Extreme care should be taken when granting this permission. It allows linking to any file or directory in the file system thus allowing the attacker access to all files.
symbolic	Ability to create symbolic links.	Extreme care should be taken when granting this permission. It allows linking to any file or directory in the file system thus allowing the attacker to access to all files.

	LinkPermission(String name) Constructs a `LinkPermission` with the specified name.
	LinkPermission(String name, String actions) Constructs a `LinkPermission` with the specified name.

From class java.security.BasicPermission

String	getActions()
boolean	implies(Permission p)

From class java.security.Permission

void	checkGuard(Object object) Determines whether or not to allow access to the guarded object `object`.
abstract String	getActions()
final String	getName()
abstract boolean	implies(Permission permission)
PermissionCollection	newPermissionCollection()

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

From interface java.security.Guard

abstract void

checkGuard(Object object)

Determines whether or not to allow access to the guarded object object.

Constructs a LinkPermission with the specified name.

name	the name of the permission. It must be "hard" or "symbolic".

IllegalArgumentException	if name is empty or invalid

Constructs a LinkPermission with the specified name.

name	the name of the permission; must be "hard" or "symbolic".
actions	the actions for the permission; must be the empty string or `null`

IllegalArgumentException	if name is empty or invalid, or actions is a non-empty string