Java ArrayBlockingQueue getArrayBlockingQueue(final Object o, final Class clazz, final int capacity)

Description

Cast an object into a typed ArrayBlockingQueue .

License

Apache License

Parameter

Parameter	Description
o	The input object
clazz	The output class
capacity	The initial capacity
T	The type of the output

Return

The casted object

Declaration

public static <T> BlockingQueue<T> getArrayBlockingQueue(final Object o, final Class<T> clazz,
        final int capacity) 

Method Source Code

//package com.java2s;
/*/* ww  w  . j a v a 2s  .  co m*/
 * #%L
 * utils-commons
 * %%
 * Copyright (C) 2016 - 2018 Gilles Landel
 * %%
 * 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.
 * #L%
 */

import java.util.Queue;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;

public class Main {
    /**
     * Cast an object into a typed {@link ArrayBlockingQueue}.
     * 
     * @param o
     *            The input object
     * @param clazz
     *            The output class
     * @param capacity
     *            The initial capacity
     * @return The casted object
     * @param <T>
     *            The type of the output
     */
    public static <T> BlockingQueue<T> getArrayBlockingQueue(final Object o, final Class<T> clazz,
            final int capacity) {
        final BlockingQueue<T> queue = new ArrayBlockingQueue<>(capacity);

        queue(queue, o, clazz, true);

        return queue;
    }

    /**
     * Cast the object and feel the queue.
     * 
     * @param queue
     *            The output queue
     * @param o
     *            The input object
     * @param classElement
     *            The typed class
     * @param removeNull
     *            If null has to be removed
     */
    private static <T> void queue(final Queue<T> queue, final Object o, final Class<T> clazz,
            final boolean removeNull) {
        if (o != null && Queue.class.isAssignableFrom(o.getClass())) {
            Queue<?> mObj = (Queue<?>) o;
            for (Object obj : mObj) {
                setQueueValue(queue, obj, clazz, removeNull);
            }
        }
    }

    /**
     * Get the class of the object ({@code null} safe).
     * 
     * @param object
     *            The object (required)
     * @param <T>
     *            The object type
     * @return The class of the object or null
     */
    @SuppressWarnings("unchecked")
    public static <T> Class<T> getClass(final T object) {
        if (object != null) {
            return (Class<T>) object.getClass();
        }
        return null;
    }

    /**
     * Set the queue value.
     * 
     * @param queue
     *            the queue
     * @param obj
     *            the object
     * @param clazz
     *            the class
     * @param removeNull
     *            If null has to be removed
     * @param <T>
     *            The type of the element
     */
    private static <T> void setQueueValue(final Queue<T> queue, final Object obj, final Class<T> clazz,
            final boolean removeNull) {
        if (obj != null && clazz.isAssignableFrom(obj.getClass())) {
            queue.add(clazz.cast(obj));
        } else if (obj == null && !removeNull) {
            queue.add(null);
        }
    }

    /**
     * Auto cast an object.
     * 
     * @param object
     *            The object (required)
     * @param <T>
     *            The object type
     * @return The casted object
     * @throws ClassCastException
     *             on cast failure
     */
    @SuppressWarnings("unchecked")
    public static <T> T cast(final Object object) {
        return (T) object;
    }

    /**
     * Cast an object into the specified class (null safe).
     * 
     * @param o
     *            The input object (required)
     * @param clazz
     *            The output class (required)
     * @return The casted object or {@code null}
     * @param <T>
     *            The type of the output
     */
    public static <T> T cast(final Object o, final Class<T> clazz) {
        if (o != null && clazz != null && clazz.isAssignableFrom(o.getClass())) {
            return clazz.cast(o);
        }
        return null;
    }
}

Related

1. createUniqueHelperParamQueue(String uniqueQueueName, int size)
2. getParameterQueueSize(String queueName)
3. newArrayBlockingQueue()
4. newArrayBlockingQueue(final int capacity)
5. newArrayBlockingQueue(int capacity)