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/* * Copyright 2002-2018 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 * * https://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.AbstractFileResolvingResource; import org.springframework.core.io.ContextResource; import org.springframework.core.io.Resource; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.ResourceUtils; 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 AbstractFileResolvingResource 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"); String pathToUse = StringUtils.cleanPath(path); if (!pathToUse.startsWith("/")) { pathToUse = "/" + pathToUse; } this.path = pathToUse; } /** * 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) */ @Override 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}, * which returns {@code null} in case of a non-readable resource (e.g. a directory). * @see javax.servlet.ServletContext#getResourceAsStream(String) */ @Override public boolean isReadable() { InputStream is = this.servletContext.getResourceAsStream(this.path); if (is != null) { try { is.close(); } catch (IOException ex) { // ignore } return true; } else { return false; } } @Override public boolean isFile() { try { URL url = this.servletContext.getResource(this.path); if (url != null && ResourceUtils.isFileURL(url)) { return true; } else { return (this.servletContext.getRealPath(this.path) != 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) */ @Override 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) */ @Override 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 resolves "file:" URLs or alternatively delegates to * {@code ServletContext.getRealPath}, throwing a FileNotFoundException * if not found or not resolvable. * @see javax.servlet.ServletContext#getResource(String) * @see javax.servlet.ServletContext#getRealPath(String) */ @Override public File getFile() throws IOException { URL url = this.servletContext.getResource(this.path); if (url != null && ResourceUtils.isFileURL(url)) { // Proceed with file system resolution... return super.getFile(); } else { 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) */ @Override 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) */ @Override @Nullable public String getFilename() { return StringUtils.getFilename(this.path); } /** * This implementation returns a description that includes the ServletContext * resource location. */ @Override public String getDescription() { return "ServletContext resource [" + this.path + "]"; } @Override public String getPathWithinContext() { return this.path; } /** * This implementation compares the underlying ServletContext resource locations. */ @Override public boolean equals(@Nullable Object other) { if (this == other) { return true; } if (!(other instanceof ServletContextResource)) { return false; } ServletContextResource otherRes = (ServletContextResource) other; return (this.servletContext.equals(otherRes.servletContext) && this.path.equals(otherRes.path)); } /** * This implementation returns the hash code of the underlying * ServletContext resource location. */ @Override public int hashCode() { return this.path.hashCode(); } }