api/src/java/org/apache/fulcrum/security/spi/AbstractRoleManager.java

package org.apache.fulcrum.security.spi;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import org.apache.commons.lang3.StringUtils;
import org.apache.fulcrum.security.RoleManager;
import org.apache.fulcrum.security.entity.Role;
import org.apache.fulcrum.security.util.DataBackendException;
import org.apache.fulcrum.security.util.EntityExistsException;
import org.apache.fulcrum.security.util.UnknownEntityException;

/**
 *
 * This implementation keeps all objects in memory. This is mostly meant to help
 * with testing and prototyping of ideas.
 *
 * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
 * @version $Id$
 */
public abstract class AbstractRoleManager extends AbstractEntityManager implements RoleManager
{
    /** default serial id */
	private static final long serialVersionUID = 1L;

	/**
	 * @param <T>
	 * @param role to persist
	 * @return the Role object
	 * @throws DataBackendException if fail to connect to datasource
	 */
	protected abstract <T extends Role> T persistNewRole(T role) throws DataBackendException;

    /**
     * Construct a blank Role object.
     *
     * This method calls getRoleClass, and then creates a new object using the
     * default constructor.
     *
     * @param <T>
     * @return an object implementing Role interface.
     * @throws DataBackendException
     *             if the object could not be instantiated.
     */
    @Override
	public <T extends Role> T getRoleInstance() throws DataBackendException
    {
        try
        {
            @SuppressWarnings("unchecked")
			T role = (T) Class.forName(getClassName()).newInstance();
            return role;
        }
        catch (Exception e)
        {
            throw new DataBackendException("Problem creating instance of class " + getClassName(), e);
        }
    }

    /**
     * Construct a blank Role object.
     *
     * This method calls getRoleClass, and then creates a new object using the
     * default constructor.
     * 
     * @param <T>
     *
     * @param roleName
     *            The name of the role.
     *
     * @return an object implementing Role interface.
     *
     * @throws DataBackendException
     *             if the object could not be instantiated.
     */
    @Override
	public <T extends Role> T getRoleInstance(String roleName) throws DataBackendException
    {
        T role = getRoleInstance();
        role.setName(roleName);
        return role;
    }

    /**
     * Retrieve a Role object with specified name.
     *
     * @see org.apache.fulcrum.security.RoleManager#getRoleByName(java.lang.String)
     * 
     * @param <T>
     *
     * @param name
     *            the name of the Role.
     * @return an object representing the Role with specified name.
     * @throws DataBackendException
     *             if there was an error accessing the data backend.
     * @throws UnknownEntityException
     *             if the role does not exist.
     * 
     */
    @Override
	public <T extends Role> T getRoleByName(String name) throws DataBackendException, UnknownEntityException
    {
        @SuppressWarnings("unchecked")
		T role = (T) getAllRoles().getByName(name);
        if (role == null)
        {
            throw new UnknownEntityException("The specified role does not exist");
        }
        return role;
    }

    /**
     * Retrieve a Role object with specified Id.
     * 
     * @param <T>
     *
     * @param id
     *            the ID of the Role.
     *
     * @return an object representing the Role with specified name.
     *
     * @throws UnknownEntityException
     *             if the permission does not exist in the database.
     * @throws DataBackendException
     *             if there is a problem accessing the storage.
     */
    @Override
	public <T extends Role> T getRoleById(Object id) throws DataBackendException, UnknownEntityException
    {
        @SuppressWarnings("unchecked")
		T role = (T) getAllRoles().getById(id);
        if (role == null)
        {
            throw new UnknownEntityException("The specified role does not exist");
        }
        return role;
    }

    /**
     * Creates a new role with specified attributes.
     * 
     * @param <T>
     *
     * @param role
     *            the object describing the role to be created.
     * @return a new Role object that has id set up properly.
     * @throws DataBackendException
     *             if there was an error accessing the data backend.
     * @throws EntityExistsException
     *             if the role already exists.
     */
    @Override
	public synchronized <T extends Role> T addRole(T role) throws DataBackendException, EntityExistsException
    {
        boolean roleExists = false;
        if (StringUtils.isEmpty(role.getName()))
        {
            throw new DataBackendException("Could not create a role with empty name!");
        }
//        if (role.getId() == null)
//        {
//            throw new DataBackendException("Could not create a role with an id of null!");
//        }
        try
        {
            roleExists = checkExists(role);
            if (!roleExists)
            {
                return persistNewRole(role);
            }
        }
        catch (Exception e)
        {
            throw new DataBackendException("addRole(Role) failed", e);
        }

        // the only way we could get here without return/throw triggered
        // is that the roleExists was true.
        throw new EntityExistsException("Role '" + role + "' already exists");
    }

    /**
     * Check whether a specified role exists.
     *
     * The name is used for looking up the role
     *
     * @param role
     *            The role to be checked.
     * @return true if the specified role exists
     * @throws DataBackendException
     *             if there was an error accessing the data backend.
     */
    @Override
	public boolean checkExists(Role role) throws DataBackendException
    {
        return checkExists(role.getName());
    }
}