org.apache.ibatis.cache.TransactionalCacheManager.java Source code

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Here is the source code for org.apache.ibatis.cache.TransactionalCacheManager.java

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/*
 *    Copyright 2009-2011 The MyBatis Team
 *
 *    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.apache.ibatis.cache;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.SerializationException;
import org.apache.commons.lang.SerializationUtils;
import org.apache.ibatis.cache.decorators.TransactionalCache;
import org.apache.ibatis.logging.Log;
import org.apache.ibatis.logging.LogFactory;

public class TransactionalCacheManager {

    private static final Log logger = LogFactory.getLog(TransactionalCacheManager.class);

    private Map<Cache, TransactionalCache> transactionalCaches = new HashMap<Cache, TransactionalCache>();

    public void clear(Cache cache) {
        getTransactionalCache(cache).clear();
    }

    @SuppressWarnings("unchecked")
    public <T> void putObject(Cache cache, CacheKey key, Object value) {
        ArrayList<T> arrayList = new ArrayList<T>();
        boolean flag = true;
        for (Object object : (ArrayList<?>) value)
            try {
                arrayList.add((T) cloneObject(object));
            } catch (CloneNotSupportedException e) {
                logger.error("Encounter CloneNotSupportedException When Cache Object [" + object.toString() + "]");
                flag = false;
                break;
            }
        if (flag)// if false skip cache
            getTransactionalCache(cache).putObject(key, arrayList);
    }

    public void commit() {
        for (TransactionalCache txCache : transactionalCaches.values()) {
            txCache.commit();
        }
    }

    public void rollback() {
        for (TransactionalCache txCache : transactionalCaches.values()) {
            txCache.rollback();
        }
    }

    private TransactionalCache getTransactionalCache(Cache cache) {
        TransactionalCache txCache = transactionalCaches.get(cache);
        if (txCache == null) {
            txCache = new TransactionalCache(cache);
            transactionalCaches.put(cache, txCache);
        }
        return txCache;
    }

    /**
     * ?
     * @param ?
     * @return   ??
     * @throws CloneNotSupportedException
     */
    @SuppressWarnings("unchecked")
    public static <T> T cloneObject(T obj) throws CloneNotSupportedException {
        if (obj == null) {
            return null;
        }
        if (obj instanceof Cloneable) {//implement Cloneable?clone
            Class<? extends Object> clazz = obj.getClass();
            Method m;
            try {
                m = clazz.getMethod("clone", (Class[]) null);
            } catch (NoSuchMethodException ex) {
                throw new NoSuchMethodError(ex.getMessage());
            }
            try {
                Object result = m.invoke(obj, (Object[]) null);
                return (T) result;
            } catch (InvocationTargetException ex) {
                Throwable cause = ex.getCause();
                if (cause instanceof CloneNotSupportedException) {
                    throw ((CloneNotSupportedException) cause);
                }
                throw new Error("Unexpected exception", cause);
            } catch (IllegalAccessException ex) {
                throw new IllegalAccessError(ex.getMessage());
            }
        }
        if (obj instanceof Serializable)//??????
            return (T) SerializationUtils.clone((Serializable) obj);
        throw new SerializationException();
    }

}