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FlexDoc/Javadoc 2.0 Demo Java Doc |
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. Such a pathname is called a wildcard pathname. Otherwise, it's a simple pathname.
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", "delete", and "readlink". Their meaning is defined as follows:
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.
Constructor Summary |
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Creates a new FilePermission object with the specified actions.
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Method Summary |
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boolean |
Checks two FilePermission objects for equality.
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Returns the "canonical string representation" of the actions.
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int |
hashCode()
Returns the hash code value for this object.
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boolean |
Checks if this FilePermission object "implies" the specified permission.
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Returns a new PermissionCollection object for storing FilePermission
objects.
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Methods inherited from class java.security.Permission |
Methods inherited from class java.lang.Object |
public FilePermission |
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.
If the value of the system property is set to true, path is canonicalized and stored as a String object named cpath. This means a relative path is converted to an absolute path, a Windows DOS-style 8.3 path is expanded to a long path, and a symbolic link is resolved to its target, etc.
If the value of the system property is set to false, path is converted to a Path object named npath after normalization. No canonicalization is performed which means the underlying file system is not accessed. If an InvalidPathException is thrown during the conversion, this FilePermission will be labeled as invalid.
In either case, the "*" or "-" character at the end of a wildcard path is removed before canonicalization or normalization. It is stored in a separate wildcard flag field.
The default value of the jdk.io.permissionsUseCanonicalPath system property is false in this implementation.
The value can also be set with a security property using the same name, but setting a system property will override the security property value.
public boolean implies |
(Permission p) |
More specifically, this method returns true if:
Precisely, a simple pathname implies another simple pathname if and only if they are equal. A simple pathname never implies a wildcard pathname. A wildcard pathname implies another wildcard pathname if and only if all simple pathnames implied by the latter are implied by the former. A wildcard pathname implies a simple pathname if and only if
"<<ALL FILES>>" implies every other pathname. No pathname, except for "<<ALL FILES>>" itself, implies "<<ALL FILES>>".
If jdk.io.permissionsUseCanonicalPath is false, a simple npath is inside a wildcard npath if and only if simple_npath.relativize(wildcard_npath) is exactly "..", a simple npath is recursively inside a wildcard npath if and only if simple_npath.relativize(wildcard_npath) is a series of one or more "..". This means "/-" implies "/foo" but not "foo".
An invalid FilePermission does not imply any object except for itself. An invalid FilePermission is not implied by any object except for itself or a FilePermission on "<<ALL FILES>>" whose actions is a superset of this invalid FilePermission. Even if two FilePermission are created with the same invalid path, one does not imply the other.
public boolean equals |
(Object obj) |
When jdk.io.permissionsUseCanonicalPath is false, an invalid FilePermission does not equal to any object except for itself, even if they are created using the same invalid path.
public int hashCode |
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public String getActions |
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public PermissionCollection newPermissionCollection |
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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:
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.
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FlexDoc/Javadoc 2.0 Demo Java Doc |