destbeancreator.java

一个javabean的转换与copy非常的好用希望大家好好研究一下

/*
 * Copyright 2005-2007 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 net.sf.dozer.util.mapping.util;

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

import org.apache.log4j.Logger;

import net.sf.dozer.util.mapping.BeanFactoryIF;
import net.sf.dozer.util.mapping.MappingException;
import net.sf.dozer.util.mapping.fieldmap.ClassMap;
import net.sf.dozer.util.mapping.fieldmap.DozerClass;
import net.sf.dozer.util.mapping.fieldmap.FieldMap;

/**
 * @author tierney.matt
 * @author garsombke.franz
 */
public class DestBeanCreator {
  private static final Logger log = Logger.getLogger(DestBeanCreator.class);
  
  private final Map factories;
  private final MappingUtils mappingUtils = new MappingUtils();
  
  public DestBeanCreator(Map factories) {
    this.factories = factories;
  }

  public Object create(Object srcObject, ClassMap classMap, Class destClass) 
      throws InstantiationException, IllegalAccessException, ClassNotFoundException, 
      NoSuchMethodException, InvocationTargetException {
    return create(srcObject, classMap, null, destClass);
  }

  public Object create(Object srcObject, ClassMap classMap, FieldMap fieldMap, Class destClass)
      throws InstantiationException, IllegalAccessException, ClassNotFoundException, NoSuchMethodException, InvocationTargetException {
    Object rvalue = null;
    DozerClass destClassObj = classMap.getDestClass();
    String factoryName = destClassObj.getBeanFactory();
    // see if there are any static createMethods
    if (fieldMap != null) {
      if (fieldMap.getDestField().getCreateMethod() != null) {
        return destClassObj.getClassToMap().getMethod(fieldMap.getDestField().getCreateMethod(), null).invoke(null, null);
      }
    }
    if (classMap.getDestClass().getCreateMethod() != null) {
      return destClassObj.getClassToMap().getMethod(
          classMap.getDestClass().getCreateMethod(), null).invoke(null, null);
    }
    // If factory name wasn't specified, just create new instance. Otherwise use
    // the specified custom bean factory
    if (mappingUtils.isBlankOrNull(factoryName)) {
      try {
        rvalue = destClassObj.getClassToMap().newInstance();
      } catch (InstantiationException e) {
        if (destClass != null) {
          return destClass.newInstance();
        }
        // we could be dealing with an Interface or Abstract Class which was
        // mapped using a Class Level mapId
        // try to see if the parentFieldMap dest field has a hint...
        if (fieldMap != null && fieldMap.getDestinationTypeHint() != null) {
          return fieldMap.getDestinationTypeHint().getHint().newInstance();
        } else {
          throw e;
        }
      }
    } else {
      rvalue = createFromFactory(srcObject, classMap.getSourceClass()
          .getClassToMap(), factoryName, destClassObj.getFactoryBeanId(),
          destClassObj.getClassToMap());
      // verify factory returned expected dest object type
      if (!classMap.getDestClass().getClassToMap().isAssignableFrom(
          rvalue.getClass())) {
        throw new MappingException(
            "Custom bean factory did not return correct type of destination data object.  Expected: "
                + classMap.getDestClass().getClassToMap()
                + ", Actual: "
                + rvalue.getClass());
      }
    }
    return rvalue;
  }
  
  public Object createFromFactory(Object srcObject, Class srcObjectClass, String factoryName, String factoryBeanId,
      Class destClass) throws ClassNotFoundException, IllegalAccessException, InstantiationException {

    // By default, use dest object class name for factory bean id
    String beanId = !mappingUtils.isBlankOrNull(factoryBeanId) ? factoryBeanId : destClass.getName();

    BeanFactoryIF factory = (BeanFactoryIF) factories.get(factoryName);

    if (factory == null) {
      Class factoryClass = Class.forName(factoryName);
      if (!BeanFactoryIF.class.isAssignableFrom(factoryClass)) {
        throw new MappingException("Custom bean factory must implement the BeanFactoryIF interface.");
      }
      factory = (BeanFactoryIF) factoryClass.newInstance();
      // put the created factory in our factory map
      factories.put(factoryName, factory);
    }
    Object rvalue = factory.createBean(srcObject, srcObjectClass, beanId);

    log.debug("Bean instance created with custom factory -->" + "\n  Bean Type: " + rvalue.getClass().getName()
        + "\n  Factory Name: " + factoryName);
    return rvalue;
  }

  

}