This class is for AWT permissions. An AWTPermission contains a target name but no actions list; you either have the named permission or you don't.

The target name is the name of the AWT permission (see below). The naming convention follows the hierarchical property naming convention. Also, an asterisk could be used to represent all AWT permissions.

The following table lists all the possible AWTPermission target names, and for each provides a description of what the permission allows and a discussion of the risks of granting code the permission.

Permission Target Name What the Permission Allows Risks of Allowing this Permission
accessClipboard Posting and retrieval of information to and from the AWT clipboard This would allow malfeasant code to share potentially sensitive or confidential information.
accessEventQueue Access to the AWT event queue After retrieving the AWT event queue, malicious code may peek at and even remove existing events from its event queue, as well as post bogus events which may purposefully cause the application or applet to misbehave in an insecure manner.
createRobot Create java.awt.Robot objects The java.awt.Robot object allows code to generate native-level mouse and keyboard events as well as read the screen. It could allow malicious code to control the system, run other programs, read the display, and deny mouse and keyboard access to the user.
fullScreenExclusive Enter full-screen exclusive mode Entering full-screen exclusive mode allows direct access to low-level graphics card memory. This could be used to spoof the system, since the program is in direct control of rendering.
listenToAllAWTEvents Listen to all AWT events, system-wide After adding an AWT event listener, malicious code may scan all AWT events dispatched in the system, allowing it to read all user input (such as passwords). Each AWT event listener is called from within the context of that event queue's EventDispatchThread, so if the accessEventQueue permission is also enabled, malicious code could modify the contents of AWT event queues system-wide, causing the application or applet to misbehave in an insecure manner.
readDisplayPixels Readback of pixels from the display screen Interfaces such as the java.awt.Composite interface or the java.awt.Robot class allow arbitrary code to examine pixels on the display enable malicious code to snoop on the activities of the user.
replaceKeyboardFocusManager Sets the KeyboardFocusManager for a particular thread. When SecurityManager is installed, the invoking thread must be granted this permission in order to replace the current KeyboardFocusManager. If permission is not granted, a SecurityException will be thrown.
showWindowWithoutWarningBanner Display of a window without also displaying a banner warning that the window was created by an applet Without this warning, an applet may pop up windows without the user knowing that they belong to an applet. Since users may make security-sensitive decisions based on whether or not the window belongs to an applet (entering a username and password into a dialog box, for example), disabling this warning banner may allow applets to trick the user into entering such information.
watchMousePointer Getting the information about the mouse pointer position at any time Constantly watching the mouse pointer, an applet can make guesses about what the user is doing, i.e. moving the mouse to the lower left corner of the screen most likely means that the user is about to launch an application. If a virtual keypad is used so that keyboard is emulated using the mouse, an applet may guess what is being typed.
setWindowAlwaysOnTop Setting always-on-top property of the window: Window#setAlwaysOnTop The malicious window might make itself look and behave like a real full desktop, so that information entered by the unsuspecting user is captured and subsequently misused
setAppletStub Setting the stub which implements Applet container services Malicious code could set an applet's stub and result in unexpected behavior or denial of service to an applet.

@version
1.28, 04/21/04
@author
Marianne Mueller
@author
Roland Schemers
Creates a new AWTPermission with the specified name. The name is the symbolic name of the AWTPermission, such as "topLevelWindow", "systemClipboard", etc. An asterisk may be used to indicate all AWT permissions.
Parameters
namethe name of the AWTPermission
Creates a new AWTPermission object with the specified name. The name is the symbolic name of the AWTPermission, and the actions string is currently unused and should be null.
Parameters
namethe name of the AWTPermission
actionsshould be null
Implements the guard interface for a permission. The SecurityManager.checkPermission method is called, passing this permission object as the permission to check. Returns silently if access is granted. Otherwise, throws a SecurityException.
Parameters
objectthe object being guarded (currently ignored).
Throws
SecurityException if a security manager exists and its checkPermission method doesn't allow access.
Checks two BasicPermission objects for equality. Checks that obj's class is the same as this object's class and has the same name as this object.

Parameters
objthe object we are testing for equality with this object.
Return
true if obj is a BasicPermission, and has the same name as this BasicPermission object, false otherwise.
Returns the canonical string representation of the actions, which currently is the empty string "", since there are no actions for a BasicPermission.
Return
the empty string "".
Returns the runtime class of an object. That Class object is the object that is locked by static synchronized methods of the represented class.
Return
The java.lang.Class object that represents the runtime class of the object. The result is of type {@code Class} where X is the erasure of the static type of the expression on which getClass is called.
Returns the name of this Permission. For example, in the case of a java.io.FilePermission, the name will be a pathname.
Return
the name of this Permission.
Returns the hash code value for this object. The hash code used is the hash code of the name, that is, getName().hashCode(), where getName is from the Permission superclass.
Return
a hash code value for this object.
Checks if the specified permission is "implied" by this object.

More specifically, this method returns true if:

  • p's class is the same as this object's class, and

  • p's name equals or (in the case of wildcards) is implied by this object's name. For example, "a.b.*" implies "a.b.c".
Parameters
pthe permission to check against.
Return
true if the passed permission is equal to or implied by this permission, false otherwise.
Returns a new PermissionCollection object for storing BasicPermission objects.

A BasicPermissionCollection stores a collection of BasicPermission permissions.

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

Return
a new PermissionCollection object suitable for storing BasicPermissions.
Wakes up a single thread that is waiting on this object's monitor. If any threads are waiting on this object, one of them is chosen to be awakened. The choice is arbitrary and occurs at the discretion of the implementation. A thread waits on an object's monitor by calling one of the wait methods.

The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:

  • By executing a synchronized instance method of that object.
  • By executing the body of a synchronized statement that synchronizes on the object.
  • For objects of type Class, by executing a synchronized static method of that class.

Only one thread at a time can own an object's monitor.

Throws
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
Wakes up all threads that are waiting on this object's monitor. A thread waits on an object's monitor by calling one of the wait methods.

The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Throws
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
Returns a string describing this Permission. The convention is to specify the class name, the permission name, and the actions in the following format: '("ClassName" "name" "actions")'.
Return
information about this Permission.
Causes current thread to wait until another thread invokes the method or the method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method. The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait();
         ... // Perform action appropriate to condition
     }
 
This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.
Throws
IllegalMonitorStateExceptionif the current thread is not the owner of the object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until either another thread invokes the method or the method for this object, or a specified amount of time has elapsed.

The current thread must own this object's monitor.

This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:

  • Some other thread invokes the notify method for this object and thread T happens to be arbitrarily chosen as the thread to be awakened.
  • Some other thread invokes the notifyAll method for this object.
  • Some other thread interrupts thread T.
  • The specified amount of real time has elapsed, more or less. If timeout is zero, however, then real time is not taken into consideration and the thread simply waits until notified.
The thread T is then removed from the wait set for this object and re-enabled for thread scheduling. It then competes in the usual manner with other threads for the right to synchronize on the object; once it has gained control of the object, all its synchronization claims on the object are restored to the status quo ante - that is, to the situation as of the time that the wait method was invoked. Thread T then returns from the invocation of the wait method. Thus, on return from the wait method, the synchronization state of the object and of thread T is exactly as it was when the wait method was invoked.

A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout);
         ... // Perform action appropriate to condition
     }
 
(For more information on this topic, see Section 3.2.3 in Doug Lea's "Concurrent Programming in Java (Second Edition)" (Addison-Wesley, 2000), or Item 50 in Joshua Bloch's "Effective Java Programming Language Guide" (Addison-Wesley, 2001).

If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.

Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Parameters
timeoutthe maximum time to wait in milliseconds.
Throws
IllegalArgumentExceptionif the value of timeout is negative.
IllegalMonitorStateExceptionif the current thread is not the owner of the object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until another thread invokes the method or the method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

This method is similar to the wait method of one argument, but it allows finer control over the amount of time to wait for a notification before giving up. The amount of real time, measured in nanoseconds, is given by:

 1000000*timeout+nanos

In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:

  • Another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method.
  • The timeout period, specified by timeout milliseconds plus nanos nanoseconds arguments, has elapsed.

The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout, nanos);
         ... // Perform action appropriate to condition
     }
 
This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.
Parameters
timeoutthe maximum time to wait in milliseconds.
nanosadditional time, in nanoseconds range 0-999999.
Throws
IllegalArgumentExceptionif the value of timeout is negative or the value of nanos is not in the range 0-999999.
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.