AbstractEnhancedDeserializationProxy.java

/*
 *    Copyright 2009-2024 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
 *
 *       https://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.executor.loader;

import java.lang.reflect.Method;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.ibatis.executor.ExecutorException;
import org.apache.ibatis.reflection.ExceptionUtil;
import org.apache.ibatis.reflection.factory.ObjectFactory;
import org.apache.ibatis.reflection.property.PropertyCopier;
import org.apache.ibatis.reflection.property.PropertyNamer;

/**
 * @author Clinton Begin
 */
public abstract class AbstractEnhancedDeserializationProxy {

  protected static final String FINALIZE_METHOD = "finalize";
  protected static final String WRITE_REPLACE_METHOD = "writeReplace";
  private final Class<?> type;
  private final Map<String, ResultLoaderMap.LoadPair> unloadedProperties;
  private final ObjectFactory objectFactory;
  private final List<Class<?>> constructorArgTypes;
  private final List<Object> constructorArgs;
  private final ReentrantLock lock = new ReentrantLock();
  private boolean reloadingProperty;

  protected AbstractEnhancedDeserializationProxy(Class<?> type,
      Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory,
      List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
    this.type = type;
    this.unloadedProperties = unloadedProperties;
    this.objectFactory = objectFactory;
    this.constructorArgTypes = constructorArgTypes;
    this.constructorArgs = constructorArgs;
    this.reloadingProperty = false;
  }

  public final Object invoke(Object enhanced, Method method, Object[] args) throws Throwable {
    final String methodName = method.getName();
    try {
      if (WRITE_REPLACE_METHOD.equals(methodName)) {
        final Object original;
        if (constructorArgTypes.isEmpty()) {
          original = objectFactory.create(type);
        } else {
          original = objectFactory.create(type, constructorArgTypes, constructorArgs);
        }

        PropertyCopier.copyBeanProperties(type, enhanced, original);
        return this.newSerialStateHolder(original, unloadedProperties, objectFactory, constructorArgTypes,
            constructorArgs);
      }
      lock.lock();
      try {
        if (!FINALIZE_METHOD.equals(methodName) && PropertyNamer.isProperty(methodName) && !reloadingProperty) {
          final String property = PropertyNamer.methodToProperty(methodName);
          final String propertyKey = property.toUpperCase(Locale.ENGLISH);
          if (unloadedProperties.containsKey(propertyKey)) {
            final ResultLoaderMap.LoadPair loadPair = unloadedProperties.remove(propertyKey);
            if (loadPair != null) {
              try {
                reloadingProperty = true;
                loadPair.load(enhanced);
              } finally {
                reloadingProperty = false;
              }
            } else {
              /*
               * I'm not sure if this case can really happen or is just in tests - we have an unread property but no
               * loadPair to load it.
               */
              throw new ExecutorException("An attempt has been made to read a not loaded lazy property '" + property
                  + "' of a disconnected object");
            }
          }
        }

        return enhanced;
      } finally {
        lock.unlock();
      }
    } catch (Throwable t) {
      throw ExceptionUtil.unwrapThrowable(t);
    }
  }

  protected abstract AbstractSerialStateHolder newSerialStateHolder(Object userBean,
      Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory,
      List<Class<?>> constructorArgTypes, List<Object> constructorArgs);

}