This example shows the ability of Java to declaratively restrict access to certain packages when run with SecurityManager.



By default, access to classes in "sun.*" packages is restricted. However, since Java runs without SecurityManager by default, these checks may not be always performed.







An explanation of example:







1. RestrictedPackageAccess class creates and calls sun.misc.BASE64Encoder



2. First, the default execution happens without SecurityManager, and everything is permitted



3. Secondly, SecurityManager is enabled, and the code doesn t pass the security check



4. However, when the code is run with a different policy, that allows access, the excution goes fine again.