bruteforcepropertydescriptor.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.propertydescriptor;

import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;

import net.sf.dozer.util.mapping.MappingException;
import net.sf.dozer.util.mapping.fieldmap.ClassMap;
import net.sf.dozer.util.mapping.fieldmap.Field;
import net.sf.dozer.util.mapping.fieldmap.Hint;
import net.sf.dozer.util.mapping.util.CollectionUtils;
import net.sf.dozer.util.mapping.util.DestBeanCreator;
import net.sf.dozer.util.mapping.util.MapperConstants;
import net.sf.dozer.util.mapping.util.MappingUtils;
import net.sf.dozer.util.mapping.util.ReflectionUtils;

import org.apache.log4j.Logger;

/**
 * @author garsombke.franz
 */
public class BruteForcePropertyDescriptor implements DozerPropertyDescriptorIF {

  private static final Logger log = Logger.getLogger(BruteForcePropertyDescriptor.class);

  private Method readMethod;
  private Method writeMethod;
  private PropertyDescriptor[] hierarchy;
  private final Class clazz;
  private final Field field;
  private Class returnType;
  private final ReflectionUtils reflectionUtils = new ReflectionUtils();
  private final CollectionUtils collectionUtils = new CollectionUtils();
  private final DestBeanCreator destBeanCreator = new DestBeanCreator(MappingUtils.storedFactories);//only temp use the public static factories.  The factories data needs to be relocated to a better place

  public BruteForcePropertyDescriptor(Class clazz, Field field) {
    this.field = field;
    this.clazz = clazz;
  }

  public Class getPropertyType() {
    if (returnType == null) {
      try {
        returnType = getReadMethod().getReturnType();
      } catch (Exception e) {
        log.debug("Read method exception:" + e);
        // let us try the set method - the field might not have a 'get' method
        returnType = getWriteMethod().getParameterTypes()[0];
      }
    }
    return returnType;
  }

  public void setPropertyValue(Object bean, Object value, Hint hint, ClassMap classMap) {
    try {
      if (field.getName().indexOf(MapperConstants.DEEP_FIELD_DELIMITOR) < 0) {
        if (getPropertyType().isPrimitive() && value == null) {
          // do nothing
        } else {
          //Check if dest value is already set and is equal to src value.  If true, no need to rewrite the dest value
          try {
            if (getPropertyValue(bean) == value) {
              return;
            }
          } catch (Exception e) {
            //if we failed to read the value, assume we must write, and continue...
          }  
          if (!field.isIndexed()) {
            getWriteMethod().invoke(bean, new Object[] { value });
          } else {
            writeIndexedValue(null, bean, value);
          }
        }
      } else {
        writeDeepDestinationValue(bean, value, hint, classMap);
      }
    } catch (Exception e) {
      throw new MappingException(e);
    }
  }

  public Object getPropertyValue(Object bean) {
    Object o = null;
    try {
      if (field.getName().indexOf(MapperConstants.DEEP_FIELD_DELIMITOR) < 0) {
        o = getReadMethod(clazz).invoke(bean, null);
        if (field.isIndexed()) {
          return getValueOfIndexedField(o, field.getIndex());
        } else {
          return o;
        }
      } else {
        return getDeepSrcFieldValue(bean);
      }
    } catch (Exception e) {
      throw new MappingException(e);
    }
  }

  protected Method findAMethod(Class parentDestClass, String methodName) throws NoSuchMethodException,
      ClassNotFoundException {
    // TODO USE HELPER from bean utils to find method w/ params
    StringTokenizer tokenizer = new StringTokenizer(methodName, "(");
    String m = tokenizer.nextToken();
    // If tokenizer has more elements, it mean that parameters may have been specified
    if (tokenizer.hasMoreElements()) {
      StringTokenizer tokens = new StringTokenizer(tokenizer.nextToken(), ")");
      String params = (tokens.hasMoreTokens() ? tokens.nextToken() : null);
      return findMethodWithParam(parentDestClass, m, params);
    }
    Method[] methods = parentDestClass.getMethods();
    Method result = null;
    for (int i = 0; i < methods.length; i++) {
      Method method = methods[i];
      if (method.getName().equals(methodName)) {
        // Return the first method find
        return method;
      }
    }
    return result;
  }

  private Method findMethodWithParam(Class parentDestClass, String methodName, String params)
      throws NoSuchMethodException, ClassNotFoundException {
    // TODO USE HELPER from bean utils to find method w/ params
    List list = new ArrayList();
    if (params != null) {
      StringTokenizer tokenizer = new StringTokenizer(params, ",");
      while (tokenizer.hasMoreTokens()) {
        String token = tokenizer.nextToken();
        list.add(Class.forName(token));
      }
    }
    return parentDestClass.getMethod(methodName, (Class[]) list.toArray(new Class[0]));
  }

  protected Object getDeepSrcFieldValue(Object srcObj) throws InvocationTargetException, IllegalAccessException {
    // follow deep field hierarchy. If any values are null along the way, then return null
    Object parentObj = srcObj;
    Object hierarchyValue = null;
    PropertyDescriptor[] hierarchy = getHierarchy(srcObj);
    for (int i = 0; i < hierarchy.length; i++) {
      PropertyDescriptor pd = hierarchy[i];
      hierarchyValue = pd.getReadMethod().invoke(parentObj, null);
      parentObj = hierarchyValue;
      if (hierarchyValue == null) {
        break;
      }
    }
    return hierarchyValue;
  }

  protected Method getReadMethod(Class objectClass, String fieldName) {
    PropertyDescriptor pd = reflectionUtils.getPropertyDescriptor(objectClass, fieldName);
    if ((pd == null || pd.getReadMethod() == null)) {
      throw new MappingException("Unable to determine read method for field: " + fieldName + " class: " + objectClass);
    }
    return pd.getReadMethod();
  }

  protected Method getWriteMethod(Class objectClass, String fieldName) {
    PropertyDescriptor pd = reflectionUtils.getPropertyDescriptor(objectClass, fieldName);
    if ((pd == null || pd.getWriteMethod() == null)) {
      throw new MappingException("Unable to determine write method for field: " + fieldName + " class: " + objectClass);
    }
    return pd.getWriteMethod();
  }

  protected Object getDeepDestinationValue(Object destObj) throws IllegalAccessException, InvocationTargetException,
      InstantiationException {
    // follow deep field hierarchy. If any values are null along the way, then create a new instance
    PropertyDescriptor[] hierarchy = getHierarchy(destObj);
    // first, iteratate through hierarchy and instantiate any objects that are null
    Object parentObj = destObj;
    for (int i = 0; i < hierarchy.length - 1; i++) {
      PropertyDescriptor pd = hierarchy[i];
      Object value = pd.getReadMethod().invoke(parentObj, null);
      if (value == null) {
        pd.getWriteMethod().invoke(parentObj, new Object[] { pd.getPropertyType().newInstance() });
        value = pd.getReadMethod().invoke(parentObj, null);
      }
      parentObj = value;
    }
    return parentObj;
  }