Spring Framework example source code file (ServletContextResource.java)

This example Spring Framework source code file (ServletContextResource.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

contextresource, file, filenotfoundexception, inputstream, io, ioexception, malformedurlexception, net, network, servlet, servletcontext, servletcontext, servletcontextresource, servletcontextresource, string, string, url, url

The Spring Framework ServletContextResource.java source code

/*
 * Copyright 2002-2008 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.web.context.support;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import javax.servlet.ServletContext;

import org.springframework.core.io.AbstractResource;
import org.springframework.core.io.ContextResource;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.util.WebUtils;

/**
 * {@link org.springframework.core.io.Resource} implementation for
 * {@link javax.servlet.ServletContext} resources, interpreting
 * relative paths within the web application root directory.
 *
 * <p>Always supports stream access and URL access, but only allows
 * <code>java.io.File access when the web application archive
 * is expanded.
 *
 * @author Juergen Hoeller
 * @since 28.12.2003
 * @see javax.servlet.ServletContext#getResourceAsStream
 * @see javax.servlet.ServletContext#getResource
 * @see javax.servlet.ServletContext#getRealPath
 */
public class ServletContextResource extends AbstractResource implements ContextResource {

	private final ServletContext servletContext;

	private final String path;


	/**
	 * Create a new ServletContextResource.
	 * <p>The Servlet spec requires that resource paths start with a slash,
	 * even if many containers accept paths without leading slash too.
	 * Consequently, the given path will be prepended with a slash if it
	 * doesn't already start with one.
	 * @param servletContext the ServletContext to load from
	 * @param path the path of the resource
	 */
	public ServletContextResource(ServletContext servletContext, String path) {
		// check ServletContext
		Assert.notNull(servletContext, "Cannot resolve ServletContextResource without ServletContext");
		this.servletContext = servletContext;

		// check path
		Assert.notNull(path, "Path is required");
		if (!path.startsWith("/")) {
			path = "/" + path;
		}
		this.path = StringUtils.cleanPath(path);
	}

	/**
	 * Return the ServletContext for this resource.
	 */
	public final ServletContext getServletContext() {
		return this.servletContext;
	}

	/**
	 * Return the path for this resource.
	 */
	public final String getPath() {
		return this.path;
	}


	/**
	 * This implementation checks <code>ServletContext.getResource.
	 * @see javax.servlet.ServletContext#getResource(String)
	 */
	public boolean exists() {
		try {
			URL url = this.servletContext.getResource(this.path);
			return (url != null);
		}
		catch (MalformedURLException ex) {
			return false;
		}
	}

	/**
	 * This implementation delegates to <code>ServletContext.getResourceAsStream,
	 * but throws a FileNotFoundException if no resource found.
	 * @see javax.servlet.ServletContext#getResourceAsStream(String)
	 */
	public InputStream getInputStream() throws IOException {
		InputStream is = this.servletContext.getResourceAsStream(this.path);
		if (is == null) {
			throw new FileNotFoundException("Could not open " + getDescription());
		}
		return is;
	}

	/**
	 * This implementation delegates to <code>ServletContext.getResource,
	 * but throws a FileNotFoundException if no resource found.
	 * @see javax.servlet.ServletContext#getResource(String)
	 */
	public URL getURL() throws IOException {
		URL url = this.servletContext.getResource(this.path);
		if (url == null) {
			throw new FileNotFoundException(
					getDescription() + " cannot be resolved to URL because it does not exist");
		}
		return url;
	}

	/**
	 * This implementation delegates to <code>ServletContext.getRealPath,
	 * but throws a FileNotFoundException if not found or not resolvable.
	 * @see javax.servlet.ServletContext#getRealPath(String)
	 */
	public File getFile() throws IOException {
		String realPath = WebUtils.getRealPath(this.servletContext, this.path);
		return new File(realPath);
	}

	/**
	 * This implementation creates a ServletContextResource, applying the given path
	 * relative to the path of the underlying file of this resource descriptor.
	 * @see org.springframework.util.StringUtils#applyRelativePath(String, String)
	 */
	public Resource createRelative(String relativePath) {
		String pathToUse = StringUtils.applyRelativePath(this.path, relativePath);
		return new ServletContextResource(this.servletContext, pathToUse);
	}

	/**
	 * This implementation returns the name of the file that this ServletContext
	 * resource refers to.
	 * @see org.springframework.util.StringUtils#getFilename(String)
	 */
	public String getFilename() {
		return StringUtils.getFilename(this.path);
	}

	/**
	 * This implementation returns a description that includes the ServletContext
	 * resource location.
	 */
	public String getDescription() {
		return "ServletContext resource [" + this.path + "]";
	}

	public String getPathWithinContext() {
		return this.path;
	}


	/**
	 * This implementation compares the underlying ServletContext resource locations.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (obj instanceof ServletContextResource) {
			ServletContextResource otherRes = (ServletContextResource) obj;
			return (this.servletContext.equals(otherRes.servletContext) && this.path.equals(otherRes.path));
		}
		return false;
	}

	/**
	 * This implementation returns the hash code of the underlying
	 * ServletContext resource location.
	 */
	public int hashCode() {
		return this.path.hashCode();
	}

}