org.jdbcluster.dao.Dao.java Source code

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Here is the source code for org.jdbcluster.dao.Dao.java

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/*
 * Copyright 2002-2005 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 org.jdbcluster.dao;

import java.util.HashMap;

import org.jdbcluster.JDBClusterUtil;
import org.jdbcluster.exception.ConfigurationException;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.PropertyValue;

/**
 * Basic Dao class
 * @author FaKod
 */
public abstract class Dao {

    private static DaoConfig daoConfig;

    static private HashMap<Class<?>, HashMap<String, String>> classToPropsMap = new HashMap<Class<?>, HashMap<String, String>>();

    /**
     * gets configuration class for Daos
     * @return config object
     */
    public static DaoConfig getDaoConfig() {
        return daoConfig;
    }

    /**
     * sets configuration class for Daos
     * @param daoConfig config object
     */
    public static void setDaoConfig(DaoConfig daoConfig) {
        Dao.daoConfig = daoConfig;
    }

    /**
     * creates new instance of a Dao using given Dao class
     * @param daoClass class of Object to create
     * @return created dao instance
     */
    public static Object newInstance(Class<?> daoClass) {
        Object dao = JDBClusterUtil.createClassObject(daoClass);
        //get property of DAO and initial value from jdbcluster.dao.conf.xml
        HashMap<String, String> hm;
        synchronized (classToPropsMap) {
            hm = classToPropsMap.get(daoClass);
            if (hm == null)
                hm = putCacheMap(daoClass);
        }

        BeanWrapper beanWrapper = new BeanWrapperImpl();
        beanWrapper.setWrappedInstance(dao);

        for (String prop : hm.keySet()) {
            String value = hm.get(prop);
            //get property of DAO
            Class<?> propClass = beanWrapper.getPropertyType(prop);
            //convert to Type if necessary
            Object o = beanWrapper.convertIfNecessary(value, propClass);
            //set the value of the predefined property read from jdbcluster.dao.conf.xml
            beanWrapper.setPropertyValue(new PropertyValue(prop, o));
        }
        return dao;
    }

    /**
     * caches dao configurations
     * @param daoClass class of dao object
     * @return map element
     */
    private static HashMap<String, String> putCacheMap(Class<?> daoClass) {
        DaoConfig daoConfig = Dao.getDaoConfig();
        if (daoConfig == null)
            throw new ConfigurationException("No Dao configuration present. Call Dao.setDaoConfig first");
        String daoId = daoConfig.getDaoId(daoClass.getName());
        HashMap<String, String> hm = new HashMap<String, String>();
        classToPropsMap.put(daoClass, hm);

        String[] props = daoConfig.getPropertyName(daoId);
        for (String prop : props) {
            String value = daoConfig.getPropertieValue(daoId, prop);
            hm.put(prop, value);
        }
        return hm;
    }

}