org.onebusaway.csv_entities.schema.BeanWrapperFactory Maven / Gradle / Ivy

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/**
 * Copyright (C) 2011 Brian Ferris 
 *
 * 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.onebusaway.csv_entities.schema;

import java.beans.BeanInfo;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.onebusaway.csv_entities.exceptions.IntrospectionException;
import org.onebusaway.csv_entities.exceptions.MethodInvocationException;
import org.onebusaway.csv_entities.exceptions.NoSuchPropertyException;

public class BeanWrapperFactory {

  private static Map, BeanClassWrapperImpl> _classWrappers = new HashMap, BeanClassWrapperImpl>();

  public static BeanWrapper wrap(Object object) {
    Class c = object.getClass();
    BeanClassWrapperImpl classWrapper = _classWrappers.get(c);
    if (classWrapper == null) {
      try {
        BeanInfo beanInfo = java.beans.Introspector.getBeanInfo(c);
        classWrapper = new BeanClassWrapperImpl(beanInfo);
        _classWrappers.put(c, classWrapper);
      } catch (Exception ex) {
        throw new IntrospectionException(c);
      }
    }

    return new BeanWrapperImpl(classWrapper, object);
  }

  private static class BeanClassWrapperImpl {

    private Map _readMethods = new HashMap();

    private Map _writeMethods = new HashMap();

    public BeanClassWrapperImpl(BeanInfo info) {
      PropertyDescriptor[] properties = info.getPropertyDescriptors();
      for (PropertyDescriptor property : properties) {
        String name = property.getName();
        _readMethods.put(name, property.getReadMethod());
        _writeMethods.put(name, property.getWriteMethod());
      }
    }

    public Class getPropertyType(Object object, String propertyName) {
      Method method = _readMethods.get(propertyName);
      if (method == null)
        throw new NoSuchPropertyException(object.getClass(), propertyName);
      return method.getReturnType();
    }

    public Object getPropertyValue(Object object, String propertyName) {
      Method method = _readMethods.get(propertyName);
      if (method == null)
        throw new NoSuchPropertyException(object.getClass(), propertyName);
      try {
        return method.invoke(object);
      } catch (Exception ex) {
        throw new MethodInvocationException(object.getClass(), method, ex);
      }
    }

    public void setPropertyValue(Object object, String propertyName,
        Object value) {
      Method method = _writeMethods.get(propertyName);
      if (method == null)
        throw new NoSuchPropertyException(object.getClass(), propertyName);
      try {
        method.invoke(object, value);
      } catch (Exception ex) {
        throw new MethodInvocationException(object.getClass(), method, ex);
      }
    }
  }

  private static class BeanWrapperImpl implements BeanWrapper {

    private BeanClassWrapperImpl _classWrapper;

    private Object _wrappedInstance;

    public BeanWrapperImpl(BeanClassWrapperImpl classWrapper,
        Object wrappedInstance) {
      _classWrapper = classWrapper;
      _wrappedInstance = wrappedInstance;
    }

    @SuppressWarnings("unchecked")
    public  T getWrappedInstance(Class type) {
      return (T) _wrappedInstance;
    }

    public Class getPropertyType(String propertyName) {
      return _classWrapper.getPropertyType(_wrappedInstance, propertyName);
    }

    public Object getPropertyValue(String propertyName) {
      return _classWrapper.getPropertyValue(_wrappedInstance, propertyName);
    }

    public void setPropertyValue(String propertyName, Object value) {
      _classWrapper.setPropertyValue(_wrappedInstance, propertyName, value);
    }

  }
}