com.avego.oauth.migration.OauthMigrationDaoFactory.java Source code

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Here is the source code for com.avego.oauth.migration.OauthMigrationDaoFactory.java

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/*
 * Copyright 2013 the original author or authors.
 * 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.avego.oauth.migration;

import java.lang.reflect.Constructor;
import java.util.Map;

import org.apache.commons.lang3.reflect.ConstructorUtils;

/**
 * The TokenDaoFactory represents a factory for a token DAO
 * It looks for a system property com.avego.oauth.migration.OauthMigrationDao
 * and uses that for the implementation
 * @version $Id: OauthMigrationDaoFactory.java 66251 2013-05-14 13:56:07Z conor.roche $
 * @author conorroche
 */
public class OauthMigrationDaoFactory {

    /**
     * This is the system property for the migration dao implementation also can be a param
     * in the map in which case the map param takes precedence
     */
    public static final String MIGRATION_DAO_PROPERTY = "com.avego.oauth.migration.OauthMigrationDao";
    /**
     * This is the default implementation of the migration dao
     */
    public static final String DEFAULT_MIGRATION_DAO = MysqlOauthMigrationDao.class.getName();

    /**
     * This creates an instance of a token dao
     * @param params The dao params
     * @return The token dao instance
     * @throws DaoCreationException If it failed to instantiate the dao
     */
    public static OauthMigrationDao newInstance(Map<String, Object> params) throws DaoCreationException {

        OauthMigrationDao dao = null;
        String className = System.getProperty(MIGRATION_DAO_PROPERTY, DEFAULT_MIGRATION_DAO);
        if (params != null && params.containsKey(MIGRATION_DAO_PROPERTY)) {
            String paramClassName = (String) params.get(MIGRATION_DAO_PROPERTY);
            if (paramClassName != null && paramClassName.length() > 0) {
                className = paramClassName;
            }
        }
        Constructor<OauthMigrationDao> constructor = null;
        try {
            @SuppressWarnings("unchecked")
            Class<OauthMigrationDao> clazz = (Class<OauthMigrationDao>) Class.forName(className);

            // look for a constructor that takes the jdbc template
            constructor = ConstructorUtils.getAccessibleConstructor(clazz, Map.class);
            if (constructor == null) {
                // use default no arg constructor
                constructor = ConstructorUtils.getAccessibleConstructor(clazz);
                if (constructor != null) {
                    dao = constructor.newInstance();
                }
            } else {
                dao = constructor.newInstance(params);
            }
        } catch (Exception ex) {
            throw new DaoCreationException(
                    "Failed to create the dao with the class: " + className + ", msg; " + ex.getMessage(), ex);
        }
        if (constructor == null) {
            throw new DaoCreationException("The class: " + className
                    + " Did not have a no args constructor nor a constructor taking a Map<String, Object>");
        }
        return dao;
    }

}