/*
 *  Copyright 2008 biaoping.yin
 *
 *  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.frameworkset.util.io;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;

/**
 * <p>Title: ByteArrayResource.java</p> 
 * <p>Description: </p>
 * <p>bboss workgroup</p>
 * <p>Copyright (c) 2008</p>
 * @Date 2010-11-24
 * @author biaoping.yin
 * @version 1.0
 */
public class ByteArrayResource  extends AbstractResource {

	private final byte[] byteArray;

	private final String description;


	/**
	 * Create a new ByteArrayResource.
	 * @param byteArray the byte array to wrap
	 */
	public ByteArrayResource(byte[] byteArray) {
		this(byteArray, "resource loaded from byte array");
	}

	/**
	 * Create a new ByteArrayResource.
	 * @param byteArray the byte array to wrap
	 * @param description where the byte array comes from
	 */
	public ByteArrayResource(byte[] byteArray, String description) {
		if (byteArray == null) {
			throw new IllegalArgumentException("Byte array must not be null");
		}
		this.byteArray = byteArray;
		this.description = (description != null ? description : "");
	}

	/**
	 * Return the underlying byte array.
	 */
	public final byte[] getByteArray() {
		return this.byteArray;
	}


	/**
	 * This implementation always returns <code>true</code>.
	 */
	@Override
	public boolean exists() {
		return true;
	}

	/**
	 * This implementation returns a ByteArrayInputStream for the
	 * underlying byte array.
	 * @see java.io.ByteArrayInputStream
	 */
	public InputStream getInputStream() throws IOException {
		return new ByteArrayInputStream(this.byteArray);
	}

	/**
	 * This implementation returns the passed-in description, if any.
	 */
	public String getDescription() {
		return this.description;
	}
	
	/**
	 * This implementation returns the name of the file.
	 * @see java.io.File#getName()
	 */
	public String getFilename() {
		return description;
	}


	/**
	 * This implementation compares the underlying byte array.
	 * @see java.util.Arrays#equals(byte[], byte[])
	 */
	@Override
	public boolean equals(Object obj) {
		return (obj == this ||
		    (obj instanceof ByteArrayResource && Arrays.equals(((ByteArrayResource) obj).byteArray, this.byteArray)));
	}

	/**
	 * This implementation returns the hash code based on the
	 * underlying byte array.
	 */
	@Override
	public int hashCode() {
		return (byte[].class.hashCode() * 29 * this.byteArray.length);
	}

}