15.11. Run As

Users sometimes need to perform certain operations with elevated privileges — for example, an unauthenticated user may need to create a new user account. Seam Security provides support in this situation with the RunAsOperation class. This class allows either the Principal or Subject, or the user's roles, to be overridden for a single set of operations.

The following code demonstrates RunAsOperation usage. The addRole() method is called to provide a set of roles to 'borrow' for the duration of the operation. The execute() method contains the code that will be executed with the elevated privileges.

new RunAsOperation() {       
  public void execute() {
    executePrivilegedOperation();
  }         
}.addRole("admin")
 .run();

Similarly, the getPrincipal() or getSubject() methods can also be overriden to specify the Principal and Subject instances to use for the duration of the operation. Finally, the run() method is used to carry out the RunAsOperation.