resourceloader.java

Java/J2EE application framework based on [Expert One-on-One J2EE Design and Development] by Rod John

/*
 * Copyright 2002-2004 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 org.springframework.core.io;

/**
 * Interface to be implemented by objects that can load resources.
 * An ApplicationContext is required to provide this functionality.
 *
 * <p>DefaultResourceLoader is a standalone implementation that is
 * usable outside an ApplicationContext, also used by ResourceEditor.
 *
 * @author Juergen Hoeller
 * @since 10.03.2004
 * @see DefaultResourceLoader
 * @see ResourceEditor
 * @see org.springframework.context.ApplicationContext
 */
public interface ResourceLoader {

	/** Pseudo URL prefix for loading from the class path */
	String CLASSPATH_URL_PREFIX = "classpath:";

	/**
	 * Return a Resource handle for the specified resource.
	 * The handle should always be a reusable resource descriptor,
	 * allowing for multiple getInputStream calls.
	 * <p><ul>
	 * <li>Must support fully qualified URLs, e.g. "file:C:/test.dat".
	 * <li>Must support classpath pseudo-URLs, e.g. "classpath:test.dat".
	 * <li>Should support relative file paths, e.g. "WEB-INF/test.dat".
	 * (This will be implementation-specific, typically provided by an
	 * ApplicationContext implementation.)
	 * </ul>
	 * <p>Note that a Resource handle does not imply an existing resource;
	 * you need to invoke Resource's "exists" to check for existence.
	 * @param location resource location
	 * @return Resource handle
	 * @see #CLASSPATH_URL_PREFIX
	 * @see org.springframework.core.io.Resource#exists
	 * @see org.springframework.core.io.Resource#getInputStream
	 */
	Resource getResource(String location);

}