com.boylesoftware.web.impl.auth.AbstractUserRecordHandler.java Source code

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Here is the source code for com.boylesoftware.web.impl.auth.AbstractUserRecordHandler.java

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/*
 * Copyright 2013 Boyle Software, Inc.
 *
 * Licensed 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.
 */
package com.boylesoftware.web.impl.auth;

import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.boylesoftware.web.spi.UserRecordHandler;
import com.boylesoftware.web.util.Hex;

/**
 * Simple abstract implementation of {@link UserRecordHandler} that looks up
 * user record in the database.
 *
 * @param <T> User record type. Must be a JPA entity.
 *
 * @author Lev Himmelfarb
 */
public abstract class AbstractUserRecordHandler<T> implements UserRecordHandler<T> {

    /**
     * The log.
     */
    private final Log log = LogFactory.getLog(AbstractUserRecordHandler.class);

    /**
     * User record class.
     */
    private final Class<T> userRecordClass;

    /**
     * Create new handler.
     *
     * @param userRecordClass User record class.
     */
    public AbstractUserRecordHandler(final Class<T> userRecordClass) {

        this.userRecordClass = userRecordClass;
    }

    /* (non-Javadoc)
     * @see com.boylesoftware.web.spi.UserRecordHandler#getUserObjectClass()
     */
    @Override
    public Class<T> getUserObjectClass() {

        return this.userRecordClass;
    }

    /* (non-Javadoc)
     * @see com.boylesoftware.web.spi.UserRecordHandler#getUser(int, int, javax.persistence.EntityManagerFactory)
     */
    @Override
    public T getUser(final int id, final int salt, final EntityManagerFactory emf) {

        final boolean debug = this.log.isDebugEnabled();

        if (debug) {
            this.log.debug("looking up user id " + id + ", salt " + salt + " in the database");
            this.log.debug("creating entity manager");
        }
        final EntityManager em = emf.createEntityManager();
        try {
            final T user = em.find(this.userRecordClass, Integer.valueOf(id));

            if ((user == null) || (this.getUserSalt(user) != salt)) {
                if (debug)
                    this.log.debug("user not found or salt does not match");
                return null;
            }

            if (debug)
                this.log.debug("user found");
            return user;

        } finally {
            if (debug)
                this.log.debug("closing entity manager");
            em.close();
        }
    }

    /**
     * Digest password. This is a convenience method for some implementations.
     *
     * @param password The password.
     * @param algorithm Digest algorithm (see {@link MessageDigest}).
     *
     * @return Password digest in hexadecimal encoding.
     */
    protected String digestPassword(final String password, final String algorithm) {

        try {
            final MessageDigest digester = MessageDigest.getInstance(algorithm);

            return Hex.encode(digester.digest(password.getBytes(Charset.forName("UTF-8"))));

        } catch (final NoSuchAlgorithmException e) {
            throw new IllegalArgumentException("Invalid digest algorithm.", e);
        }
    }
}