Spring Framework example source code file (SpringResourceLoader.java)

This example Spring Framework source code file (SpringResourceLoader.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

could, could, illegalargumentexception, io, ioexception, name, resourcenotfoundexception, spring_resource_loader, spring_resource_loader_class, springresourceloader, springresourceloader, string, string, util, velocity, velocity

The Spring Framework SpringResourceLoader.java source code

/*
 * Copyright 2002-2006 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.ui.velocity;

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

import org.apache.commons.collections.ExtendedProperties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.resource.Resource;
import org.apache.velocity.runtime.resource.loader.ResourceLoader;

import org.springframework.util.StringUtils;

/**
 * Velocity ResourceLoader adapter that loads via a Spring ResourceLoader.
 * Used by VelocityEngineFactory for any resource loader path that cannot
 * be resolved to a <code>java.io.File.
 *
 * <p>Note that this loader does not allow for modification detection:
 * Use Velocity's default FileResourceLoader for <code>java.io.File
 * resources.
 *
 * <p>Expects "spring.resource.loader" and "spring.resource.loader.path"
 * application attributes in the Velocity runtime: the former of type
 * <code>org.springframework.core.io.ResourceLoader, the latter a String.
 *
 * @author Juergen Hoeller
 * @since 14.03.2004
 * @see VelocityEngineFactory#setResourceLoaderPath
 * @see org.springframework.core.io.ResourceLoader
 * @see org.apache.velocity.runtime.resource.loader.FileResourceLoader
 */
public class SpringResourceLoader extends ResourceLoader {

	public static final String NAME = "spring";

	public static final String SPRING_RESOURCE_LOADER_CLASS = "spring.resource.loader.class";

	public static final String SPRING_RESOURCE_LOADER_CACHE = "spring.resource.loader.cache";

	public static final String SPRING_RESOURCE_LOADER = "spring.resource.loader";

	public static final String SPRING_RESOURCE_LOADER_PATH = "spring.resource.loader.path";


	protected final Log logger = LogFactory.getLog(getClass());

	private org.springframework.core.io.ResourceLoader resourceLoader;

	private String[] resourceLoaderPaths;


	public void init(ExtendedProperties configuration) {
		this.resourceLoader = (org.springframework.core.io.ResourceLoader)
				this.rsvc.getApplicationAttribute(SPRING_RESOURCE_LOADER);
		String resourceLoaderPath = (String) this.rsvc.getApplicationAttribute(SPRING_RESOURCE_LOADER_PATH);
		if (this.resourceLoader == null) {
			throw new IllegalArgumentException(
					"'resourceLoader' application attribute must be present for SpringResourceLoader");
		}
		if (resourceLoaderPath == null) {
			throw new IllegalArgumentException(
					"'resourceLoaderPath' application attribute must be present for SpringResourceLoader");
		}
		this.resourceLoaderPaths = StringUtils.commaDelimitedListToStringArray(resourceLoaderPath);
		for (int i = 0; i < this.resourceLoaderPaths.length; i++) {
			String path = this.resourceLoaderPaths[i];
			if (!path.endsWith("/")) {
				this.resourceLoaderPaths[i] = path + "/";
			}
		}
		if (logger.isInfoEnabled()) {
			logger.info("SpringResourceLoader for Velocity: using resource loader [" + this.resourceLoader +
					"] and resource loader paths " + Arrays.asList(this.resourceLoaderPaths));
		}
	}

	public InputStream getResourceStream(String source) throws ResourceNotFoundException {
		if (logger.isDebugEnabled()) {
			logger.debug("Looking for Velocity resource with name [" + source + "]");
		}
		for (int i = 0; i < this.resourceLoaderPaths.length; i++) {
			org.springframework.core.io.Resource resource =
					this.resourceLoader.getResource(this.resourceLoaderPaths[i] + source);
			try {
				return resource.getInputStream();
			}
			catch (IOException ex) {
				if (logger.isDebugEnabled()) {
					logger.debug("Could not find Velocity resource: " + resource);
				}
			}
		}
		throw new ResourceNotFoundException(
				"Could not find resource [" + source + "] in Spring resource loader path");
	}

	public boolean isSourceModified(Resource resource) {
		return false;
	}

	public long getLastModified(Resource resource) {
		return 0;
	}

}