limit user's permission to read only

[Cheng Zhang]

Hi, 

I'm new to Jackrabbit. Can anybody share me a piece of code about how to limit 
user's repository permission to read-only? My code below doesn't work.

            Repository repo = 
RepositoryAccessServlet.getRepository(pageContext.getServletContext());
            SessionImpl jcrsession = (SessionImpl) repo.login(new 
SimpleCredentials("admin", "admin".toCharArray()));
            UserManager userManager = jcrsession.getUserManager();
            User user = (User) userManager.getAuthorizable("anonymous"); 
            AccessControlManager accessControlManager = 
jcrsession.getAccessControlManager(); 
            String restrictedArea = "/"; 
            
org.apache.jackrabbit.api.jsr283.security.AccessControlPolicyIterator 
restrictedPolicies =
                accessControlManager.getApplicablePolicies(restrictedArea);
            
org.apache.jackrabbit.core.security.authorization.JackrabbitAccessControlList 
restrictedPolicy =
                
(org.apache.jackrabbit.core.security.authorization.JackrabbitAccessControlList) 
restrictedPolicies.nextAccessControlPolicy();
            Privilege[] readonlyPrivileges = { 
                    accessControlManager.privilegeFromName(Privilege.JCR_READ),
                    
accessControlManager.privilegeFromName(Privilege.JCR_READ_ACCESS_CONTROL),
            };
            
            restrictedPolicy.addEntry(user.getPrincipal(), readonlyPrivileges, 
true);
            accessControlManager.setPolicy(restrictedArea, restrictedPolicy);
                            
            jcrsession.save();
            jcrsession.logout();


Your kind help is appreciated greatly.

Thanks a lot,
Kevin