Name: boT120536 Date: 03/15/2001


java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)

Citing the API documentation of java.security.BasicPermission:
"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.)"
Nevertheless, BasicPermission has two constructors: BasicPermission(String name)
and BasicPermission(String name, String action). The reason for this second
constructor is mentioned in the docs: it is used by the Policy object to
instantiate new Permission objects (while it's not clear to me why the Policy
object can't use the first constructor).

When creating a user defined permission (e.g. TestPermission) that extends
BasicPermission, you _must_ implement a two-parameter constructor, otherwise the
permission remains unresolved forever, thus failing every checkPermission(). It
cost me an entire day to find this out; to the best of my knowledge, this is not
mentioned in any docs.

For clarity, I give some sample code:

public class TestPermissionA extends java.security.BasicPermission {
    public TestPermissionA(String name) {
        super(name);
    }
}

public class TestPermissionB extends java.security.BasicPermission {
    public TestPermissionB(String name) {
        super(name);
    }
    public TestPermissionB(String name, String action) {
        System.out.println("SECOND CONSTRUCTOR CALLED!");
        super(name, action);
    }
}

TestPermissionA seems to remain unresolved after the class has been loaded. Any
checkPermission on TestPermissionA will fail, even if the policy file grants
TestPermissionA to the executing CodeSource.
TestPermissionB works fine. Try it: you will notice that the second constructor
is actually used by the Policy class, while there might be no reason to
implement this constructor!
(Review ID: 114959)
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