| java.lang.Object
 java.security.Permission
java.io.FilePermission
| FilePermission | | final public class FilePermission extends Permission implements Serializable(Code) | | This class represents access to a file or directory. A FilePermission consists
of a pathname and a set of actions valid for that pathname.
Pathname is the pathname of the file or directory granted the specified
actions. A pathname that ends in "/*" (where "/" is
the file separator character, File.separatorChar) indicates
all the files and directories contained in that directory. A pathname
that ends with "/-" indicates (recursively) all files
and subdirectories contained in that directory. A pathname consisting of
the special token "<<ALL FILES>>" matches any file.
Note: A pathname consisting of a single "*" indicates all the files
in the current directory, while a pathname consisting of a single "-"
indicates all the files in the current directory and
(recursively) all files and subdirectories contained in the current
directory.
The actions to be granted are passed to the constructor in a string containing
a list of one or more comma-separated keywords. The possible keywords are
"read", "write", "execute", and "delete". Their meaning is defined as follows:
- read
- read permission
- write
- write permission
- execute
- execute permission. Allows
Runtime.exec to
be called. Corresponds to SecurityManager.checkExec.
- delete
- delete permission. Allows
File.delete to
be called. Corresponds to SecurityManager.checkDelete.
The actions string is converted to lowercase before processing.
Be careful when granting FilePermissions. Think about the implications
of granting read and especially write access to various files and
directories. The "<<ALL FILES>>" permission with write action is
especially dangerous. This grants permission to write to the entire
file system. One thing this effectively allows is replacement of the
system binary, including the JVM runtime environment.
Please note: Code can always read a file from the same
directory it's in (or a subdirectory of that directory); it does not
need explicit permission to do so.
See Also: java.security.Permission
See Also: java.security.Permissions
See Also: java.security.PermissionCollection
version:
1.86 07/05/05
author:
Marianne Mueller
author:
Roland Schemers
since:
1.2 |
| Constructor Summary | |
| public | FilePermission(String path, String actions)
Creates a new FilePermission object with the specified actions.
path is the pathname of a file or directory, and actions
contains a comma-separated list of the desired actions granted on the
file or directory. | | | FilePermission(String path, int mask)
Creates a new FilePermission object using an action mask.
More efficient than the FilePermission(String, String) constructor.
Can be used from within
code that needs to create a FilePermission object to pass into the
implies method. |
| Method Summary | |
| public boolean | equals(Object obj)
Checks two FilePermission objects for equality. | | public String | getActions()
Returns the "canonical string representation" of the actions.
That is, this method always returns present actions in the following order:
read, write, execute, delete. | | int | getMask()
Return the current action mask. | | public int | hashCode()
Returns the hash code value for this object. | | public boolean | implies(Permission p)
Checks if this FilePermission object "implies" the specified permission.
More specifically, this method returns true if:
- p is an instanceof FilePermission,
- p's actions are a proper subset of this
object's actions, and
- p's pathname is implied by this object's
pathname.
| | boolean | impliesIgnoreMask(FilePermission that)
Checks if the Permission's actions are a proper subset of the
this object's actions. | | public PermissionCollection | newPermissionCollection()
Returns a new PermissionCollection object for storing FilePermission
objects.
FilePermission 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.
For example, if you have two FilePermissions:
-
"/tmp/-", "read"
-
"/tmp/scratch/foo", "write"
and you are calling the implies method with the FilePermission:
"/tmp/scratch/foo", "read,write",
then the implies function must
take into account both the "/tmp/-" and "/tmp/scratch/foo"
permissions, so the effective permission is "read,write",
and implies returns true. |
| FilePermission | | public FilePermission(String path, String actions)(Code) | | Creates a new FilePermission object with the specified actions.
path is the pathname of a file or directory, and actions
contains a comma-separated list of the desired actions granted on the
file or directory. Possible actions are
"read", "write", "execute", and "delete".
A pathname that ends in "/*" (where "/" is
the file separator character, File.separatorChar)
indicates all the files and directories contained in that directory.
A pathname that ends with "/-" indicates (recursively) all files and
subdirectories contained in that directory. The special pathname
"<<ALL FILES>>" matches any file.
A pathname consisting of a single "*" indicates all the files
in the current directory, while a pathname consisting of a single "-"
indicates all the files in the current directory and
(recursively) all files and subdirectories contained in the current
directory.
A pathname containing an empty string represents an empty path.
Parameters:
path - the pathname of the file/directory.
Parameters:
actions - the action string.
throws:
IllegalArgumentException - If actions is null, empty or contains an actionother than the specified possible actions. |
| FilePermission | | FilePermission(String path, int mask)(Code) | | Creates a new FilePermission object using an action mask.
More efficient than the FilePermission(String, String) constructor.
Can be used from within
code that needs to create a FilePermission object to pass into the
implies method.
Parameters:
path - the pathname of the file/directory.
Parameters:
mask - the action mask to use. |
| equals | | public boolean equals(Object obj)(Code) | | Checks two FilePermission objects for equality. Checks that obj is
a FilePermission, and has the same pathname and actions as this object.
Parameters:
obj - the object we are testing for equality with this object. true if obj is a FilePermission, and has the samepathname and actions as this FilePermission object,false otherwise. |
| getActions | | public String getActions()(Code) | | Returns the "canonical string representation" of the actions.
That is, this method always returns present actions in the following order:
read, write, execute, delete. For example, if this FilePermission object
allows both write and read actions, a call to getActions
will return the string "read,write".
the canonical string representation of the actions. |
| getMask | | int getMask()(Code) | | Return the current action mask. Used by the FilePermissionCollection.
the actions mask. |
| hashCode | | public int hashCode()(Code) | | Returns the hash code value for this object.
a hash code value for this object. |
| implies | | public boolean implies(Permission p)(Code) | | Checks if this FilePermission object "implies" the specified permission.
More specifically, this method returns true if:
- p is an instanceof FilePermission,
- p's actions are a proper subset of this
object's actions, and
- p's pathname is implied by this object's
pathname. For example, "/tmp/*" implies "/tmp/foo", since
"/tmp/*" encompasses all files in the "/tmp" directory,
including the one named "foo".
Parameters:
p - the permission to check against. true if the specified permission is notnull and is implied by this object,false otherwise. |
| impliesIgnoreMask | | boolean impliesIgnoreMask(FilePermission that)(Code) | | Checks if the Permission's actions are a proper subset of the
this object's actions. Returns the effective mask iff the
this FilePermission's path also implies that FilePermission's path.
Parameters:
that - the FilePermission to check against.
Parameters:
exact - return immediately if the masks are not equal the effective mask |
| newPermissionCollection | | public PermissionCollection newPermissionCollection()(Code) | | Returns a new PermissionCollection object for storing FilePermission
objects.
FilePermission 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.
For example, if you have two FilePermissions:
-
"/tmp/-", "read"
-
"/tmp/scratch/foo", "write"
and you are calling the implies method with the FilePermission:
"/tmp/scratch/foo", "read,write",
then the implies function must
take into account both the "/tmp/-" and "/tmp/scratch/foo"
permissions, so the effective permission is "read,write",
and implies returns true. The "implies" semantics for
FilePermissions are handled properly by the PermissionCollection object
returned by this newPermissionCollection method.
a new PermissionCollection object suitable for storing FilePermissions. |
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