com.expedia.seiso.domain.meta.DynaItem.java Source code

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Here is the source code for com.expedia.seiso.domain.meta.DynaItem.java

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/* 
 * Copyright 2013-2015 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 com.expedia.seiso.domain.meta;

import java.beans.PropertyDescriptor;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;

import lombok.Getter;
import lombok.NonNull;
import lombok.SneakyThrows;
import lombok.val;

import org.springframework.beans.BeanUtils;

import com.expedia.seiso.core.ann.Key;
import com.expedia.seiso.domain.entity.Item;

/**
 * {@link Item} wrapper to support dynamic access to a given item's properties and metamodel.
 * 
 * @author Willie Wheeler
 */
public class DynaItem {
    @Getter
    private final Class<?> itemClass;
    @Getter
    private final Item item;
    @Getter
    private PropertyDescriptor metaKeyProperty;
    @Getter
    private Serializable metaKey;

    public DynaItem(@NonNull Item item) {
        this.item = item;
        this.itemClass = item.getClass();

        String metaKeyFieldName = null;

        // Use currClass to search up the inheritance hierarchy. We need this for example to find the @Key for Vip
        // subclasses, since the @Key is defined in Vip.
        Class<?> currClass = itemClass;
        do {
            val fields = currClass.getDeclaredFields();
            for (val field : fields) {
                val anns = field.getAnnotations();
                for (val ann : anns) {
                    if (ann.annotationType() == Key.class) {
                        metaKeyFieldName = field.getName();
                    }
                }
            }
        } while (metaKeyFieldName == null && (currClass = currClass.getSuperclass()) != null);

        // FIXME This doesn't handle compound keys. Use the ItemKey instead! [WLW]
        // If there's no explicit @Key, then use the ID by default.
        if (metaKeyFieldName == null) {
            metaKeyFieldName = "id";
        }

        this.metaKeyProperty = BeanUtils.getPropertyDescriptor(itemClass, metaKeyFieldName);
        val metaKeyGetter = metaKeyProperty.getReadMethod();

        try {
            this.metaKey = (Serializable) metaKeyGetter.invoke(item);
        } catch (IllegalAccessException | InvocationTargetException e) {
            throw new RuntimeException(e);
        }

        // log.trace("Using key {}={} for itemClass={}", metaKeyFieldName, metaKey, itemClass.getSimpleName());
    }

    /**
     * Returns the specified property value for the underlying item.
     * 
     * @param propertyName
     *            Property name
     * @return Property value
     */
    @SneakyThrows
    public Object getPropertyValue(@NonNull String propertyName) {
        val desc = BeanUtils.getPropertyDescriptor(itemClass, propertyName);
        val getter = desc.getReadMethod();
        return getter.invoke(item);
    }

    /**
     * Sets the specified property value on the underlying item.
     * 
     * @param propertyName
     *            Property name
     * @param propertyValue
     *            Property value
     */
    @SneakyThrows
    public void setPropertyValue(@NonNull String propertyName, Object propertyValue) {
        val desc = BeanUtils.getPropertyDescriptor(itemClass, propertyName);
        val setter = desc.getWriteMethod();
        setter.invoke(item, propertyValue);
    }
}