Java Permission类代码示例

import java.security.acl.Permission; //导入依赖的package包/类
private AclEntryImpl (AclEntryImpl i) throws UnknownHostException {
      setPrincipal(i.getPrincipal());
      permList = new Vector<Permission>();
      commList = new Vector<String>();

      for (Enumeration<String> en = i.communities(); en.hasMoreElements();){
        addCommunity(en.nextElement());
      }

      for (Enumeration<Permission> en = i.permissions(); en.hasMoreElements();){
        addPermission(en.nextElement());
      }
      if (i.isNegative()) setNegativePermissions();
}
 

import java.security.acl.Permission; //导入依赖的package包/类
/**
 * Returns an enumeration for the set of allowed permissions for
 * the specified principal
 * (representing an entity such as an individual or a group).
 * This set of allowed permissions is calculated as follows:
 * <UL>
 * <LI>If there is no entry in this Access Control List for the specified
 * principal, an empty permission set is returned.</LI>
 * <LI>Otherwise, the principal's group permission sets are determined.
 * (A principal can belong to one or more groups, where a group is a group
 * of principals, represented by the Group interface.)</LI>
 * </UL>
 * @param user the principal whose permission set is to be returned.
 * @return the permission set specifying the permissions the principal
 *     is allowed.
 * @see java.security.Principal
 */
@Override
public Enumeration<Permission> getPermissions(Principal user){
      Vector<Permission> empty = new Vector<>();
      for (Enumeration<AclEntry> e = entryList.elements();e.hasMoreElements();){
        AclEntry ent = e.nextElement();
        if (ent.getPrincipal().equals(user))
              return ent.permissions();
      }
      return empty.elements();
}
 

import java.security.acl.Permission; //导入依赖的package包/类
/**
 * Checks whether or not the specified principal has the specified
 * permission.
 * If it does, true is returned, otherwise false is returned.
 * More specifically, this method checks whether the passed permission
 * is a member of the allowed permission set of the specified principal.
 * The allowed permission set is determined by the same algorithm as is
 * used by the getPermissions method.
 *
 * @param user the principal, assumed to be a valid authenticated Principal.
 * @param perm the permission to be checked for.
 * @return true if the principal has the specified permission,
 *         false otherwise.
 * @see java.security.Principal
 * @see java.security.Permission
 */
@Override
public boolean checkPermission(Principal user,
                               java.security.acl.Permission perm) {
      for (Enumeration<AclEntry> e = entryList.elements();e.hasMoreElements();){
        AclEntry ent = e.nextElement();
        if (ent.getPrincipal().equals(user))
              if (ent.checkPermission(perm)) return true;
      }
      return false;
}