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BasicPermission.javaAPI DocJava SE 6 API16014Tue Jun 10 00:25:46 BST 2008java.security

BasicPermission

public abstract class BasicPermission extends Permission implements Serializable
The BasicPermission class extends the Permission class, and can be used as the base class for permissions that want to follow the same naming convention as BasicPermission.

The name for a BasicPermission is the name of the given permission (for example, "exit", "setFactory", "print.queueJob", etc). The naming convention follows the hierarchical property naming convention. An asterisk may appear by itself, or if immediately preceded by a "." may appear at the end of the name, to signify a wildcard match. For example, "*" and "java.*" are valid, while "*java", "a*b", and "java*" are not valid.

The action string (inherited from Permission) is unused. Thus, BasicPermission is commonly used as the base class for "named" permissions (ones that contain a name but no actions list; you either have the named permission or you don't.) Subclasses may implement actions on top of BasicPermission, if desired.

see
java.security.Permission
see
java.security.Permissions
see
java.security.PermissionCollection
see
java.lang.RuntimePermission
see
java.security.SecurityPermission
see
java.util.PropertyPermission
see
java.awt.AWTPermission
see
java.net.NetPermission
see
java.lang.SecurityManager
version
1.44 05/11/17
author
Marianne Mueller
author
Roland Schemers

Fields Summary
private static final long
serialVersionUID
private transient boolean
wildcard
private transient String
path
private transient boolean
exitVM
Constructors Summary
public BasicPermission(String name)
Creates a new BasicPermission with the specified name. Name is the symbolic name of the permission, such as "setFactory", "print.queueJob", or "topLevelWindow", etc.

param
name the name of the BasicPermission.
throws
NullPointerException if name is null.
throws
IllegalArgumentException if name is empty.

	super(name);
	init(name);
    
public BasicPermission(String name, String actions)
Creates a new BasicPermission object with the specified name. The name is the symbolic name of the BasicPermission, and the actions String is currently unused.

param
name the name of the BasicPermission.
param
actions ignored.
throws
NullPointerException if name is null.
throws
IllegalArgumentException if name is empty.

	super(name);
	init(name);
    
Methods Summary
public booleanequals(java.lang.Object obj)
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.

param
obj the 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.

	if (obj == this)
	    return true;

	if ((obj == null) || (obj.getClass() != getClass()))
	    return false;

	BasicPermission bp = (BasicPermission) obj;

	return getCanonicalName().equals(bp.getCanonicalName());
    
public java.lang.StringgetActions()
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 "".

	return "";
    
final java.lang.StringgetCanonicalName()
Returns the canonical name of this BasicPermission. All internal invocations of getName should invoke this method, so that the pre-JDK 1.6 "exitVM" and current "exitVM.*" permission are equivalent in equals/hashCode methods.

return
the canonical name of this BasicPermission.

	return exitVM ? "exitVM.*" : getName();
    
public inthashCode()
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.

	return this.getCanonicalName().hashCode();
    
public booleanimplies(java.security.Permission p)
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".

param
p the permission to check against.
return
true if the passed permission is equal to or implied by this permission, false otherwise.

	if ((p == null) || (p.getClass() != getClass()))
	    return false;

	BasicPermission that = (BasicPermission) p;

	if (this.wildcard) {
	    if (that.wildcard) {
		// one wildcard can imply another
		return that.path.startsWith(path);
	    } else {
		// make sure ap.path is longer so a.b.* doesn't imply a.b
		return (that.path.length() > this.path.length()) &&
		    that.path.startsWith(this.path);
	    }
	} else {
	    if (that.wildcard) {
		// a non-wildcard can't imply a wildcard
		return false;
	    }
	    else {
		return this.path.equals(that.path);
	    }
	}
    
private voidinit(java.lang.String name)
initialize a BasicPermission object. Common to all constructors.


                 

       
    
	if (name == null)
	    throw new NullPointerException("name can't be null");

	int len = name.length();
	    
	if (len == 0) {
	    throw new IllegalArgumentException("name can't be empty");
	}

	char last = name.charAt(len - 1);

	// Is wildcard or ends with ".*"?
	if (last == '*" && (len == 1 || name.charAt(len - 2) == '.")) {
	    wildcard = true;
	    if (len == 1) {
		path = "";
	    } else {
		path = name.substring(0, len - 1);
	    }
	} else {
	    if (name.equals("exitVM")) {
		wildcard = true;
		path = "exitVM.";
		exitVM = true;
	    } else {
		path = name;
	    }
	}
    
public java.security.PermissionCollectionnewPermissionCollection()
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.

	return new BasicPermissionCollection();
    
private voidreadObject(java.io.ObjectInputStream s)
readObject is called to restore the state of the BasicPermission from a stream.

	s.defaultReadObject();
	// init is called to initialize the rest of the values.
	init(getCanonicalName());