org.apache.juneau.objecttools.ObjectViewer Maven / Gradle / Ivy

Go to download
// ***************************************************************************************************************************
// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
// * to you 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.apache.juneau.objecttools;

import static org.apache.juneau.internal.CollectionUtils.*;

import java.lang.reflect.*;
import java.util.*;

import org.apache.juneau.*;
import org.apache.juneau.internal.*;

/**
 * POJO model viewer.
 *
 * 
 * 	This class is designed to extract properties from collections of maps or beans.
 * 
 *
 * Example:
 * 
 * 	MyBean[] arrayOfBeans = ...;
 * 	ObjectViewer viewer = ObjectViewer.create();
 *
 * 	// Returns the 'foo' and 'bar' properties extracted into a list of maps.
 * 	List<Map> result = viewer.run(arrayOfBeans, "foo,bar");
 * 
 * 
 * 	The tool can be used against the following data types:
 * 
 * 
 * 	Arrays/collections of maps or beans.
 * 	
Singular maps or beans.
 * 
 *
 * See Also:

 * 	Overview > juneau-marshall > Object Tools

 * 
 */
@SuppressWarnings({"unchecked","rawtypes"})
public final class ObjectViewer implements ObjectTool {

	//-----------------------------------------------------------------------------------------------------------------
	// Static
	//-----------------------------------------------------------------------------------------------------------------

	/**
	 * Default reusable searcher.
	 */
	public static final ObjectViewer DEFAULT = new ObjectViewer();

	/**
	 * Static creator.
	 *
	 * @return A new {@link ObjectViewer} object.
	 */
	public static ObjectViewer create() {
		return new ObjectViewer();
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Instance
	//-----------------------------------------------------------------------------------------------------------------

	/**
	 * Runs this viewer on the specified collection or array of objects.
	 *
	 * @param input The input.  Must be an array or collection.
	 * @param args The view args.  See {@link ViewArgs} for format.
	 * @return The extracted properties from the collection of objects.
	 */
	public List run(Object input, String args) {
		return (List)run(BeanContext.DEFAULT_SESSION, input, ViewArgs.create(args));
	}

	/**
	 * Runs this viewer on a singleton object.
	 *
	 * @param input The input.  Must be a singleton object.
	 * @param args The view args.  See {@link ViewArgs} for format.
	 * @return The extracted properties from the object.
	 */
	public Map runSingle(Object input, String args) {
		return (Map)run(BeanContext.DEFAULT_SESSION, input, ViewArgs.create(args));
	}

	@Override /* ObjectTool */
	public Object run(BeanSession session, Object input, ViewArgs args) {

		if (input == null)
			return null;

		List view = args.getView();
		ClassMeta type = session.getClassMetaForObject(input);

		if (type.isBeanMap())
			return new DelegateBeanMap(((BeanMap)input).getBean(), session).filterKeys(view);
		if (type.isMap())
			return new DelegateMap((Map)input, session).filterKeys(view);
		if (type.isBean())
			return new DelegateBeanMap(input, session).filterKeys(view);

		ArrayList