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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.core.io; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.net.URL; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.ClassUtils; import org.springframework.util.ObjectUtils; import org.springframework.util.StringUtils; /** * {@link Resource} implementation for class path resources. Uses either a * given {@link ClassLoader} or a given {@link Class} for loading resources. * * <p>Supports resolution as {@code java.io.File} if the class path * resource resides in the file system, but not for resources in a JAR. * Always supports resolution as URL. * * @author Juergen Hoeller * @author Sam Brannen * @since 28.12.2003 * @see ClassLoader#getResourceAsStream(String) * @see Class#getResourceAsStream(String) */ public class ClassPathResource extends AbstractFileResolvingResource { private final String path; @Nullable private ClassLoader classLoader; @Nullable private Class<?> clazz; /** * Create a new {@code ClassPathResource} for {@code ClassLoader} usage. * A leading slash will be removed, as the ClassLoader resource access * methods will not accept it. * <p>The thread context class loader will be used for * loading the resource. * @param path the absolute path within the class path * @see java.lang.ClassLoader#getResourceAsStream(String) * @see org.springframework.util.ClassUtils#getDefaultClassLoader() */ public ClassPathResource(String path) { this(path, (ClassLoader) null); } /** * Create a new {@code ClassPathResource} for {@code ClassLoader} usage. * A leading slash will be removed, as the ClassLoader resource access * methods will not accept it. * @param path the absolute path within the classpath * @param classLoader the class loader to load the resource with, * or {@code null} for the thread context class loader * @see ClassLoader#getResourceAsStream(String) */ public ClassPathResource(String path, @Nullable ClassLoader classLoader) { Assert.notNull(path, "Path must not be null"); String pathToUse = StringUtils.cleanPath(path); if (pathToUse.startsWith("/")) { pathToUse = pathToUse.substring(1); } this.path = pathToUse; this.classLoader = (classLoader != null ? classLoader : ClassUtils.getDefaultClassLoader()); } /** * Create a new {@code ClassPathResource} for {@code Class} usage. * The path can be relative to the given class, or absolute within * the classpath via a leading slash. * @param path relative or absolute path within the class path * @param clazz the class to load resources with * @see java.lang.Class#getResourceAsStream */ public ClassPathResource(String path, @Nullable Class<?> clazz) { Assert.notNull(path, "Path must not be null"); this.path = StringUtils.cleanPath(path); this.clazz = clazz; } /** * Create a new {@code ClassPathResource} with optional {@code ClassLoader} * and {@code Class}. Only for internal usage. * @param path relative or absolute path within the classpath * @param classLoader the class loader to load the resource with, if any * @param clazz the class to load resources with, if any * @deprecated as of 4.3.13, in favor of selective use of * {@link #ClassPathResource(String, ClassLoader)} vs {@link #ClassPathResource(String, Class)} */ @Deprecated protected ClassPathResource(String path, @Nullable ClassLoader classLoader, @Nullable Class<?> clazz) { this.path = StringUtils.cleanPath(path); this.classLoader = classLoader; this.clazz = clazz; } /** * Return the path for this resource (as resource path within the class path). */ public final String getPath() { return this.path; } /** * Return the ClassLoader that this resource will be obtained from. */ @Nullable public final ClassLoader getClassLoader() { return (this.clazz != null ? this.clazz.getClassLoader() : this.classLoader); } /** * This implementation checks for the resolution of a resource URL. * @see java.lang.ClassLoader#getResource(String) * @see java.lang.Class#getResource(String) */ @Override public boolean exists() { return (resolveURL() != null); } /** * Resolves a URL for the underlying class path resource. * @return the resolved URL, or {@code null} if not resolvable */ @Nullable protected URL resolveURL() { if (this.clazz != null) { return this.clazz.getResource(this.path); } else if (this.classLoader != null) { return this.classLoader.getResource(this.path); } else { return ClassLoader.getSystemResource(this.path); } } /** * This implementation opens an InputStream for the given class path resource. * @see java.lang.ClassLoader#getResourceAsStream(String) * @see java.lang.Class#getResourceAsStream(String) */ @Override public InputStream getInputStream() throws IOException { InputStream is; if (this.clazz != null) { is = this.clazz.getResourceAsStream(this.path); } else if (this.classLoader != null) { is = this.classLoader.getResourceAsStream(this.path); } else { is = ClassLoader.getSystemResourceAsStream(this.path); } if (is == null) { throw new FileNotFoundException(getDescription() + " cannot be opened because it does not exist"); } return is; } /** * This implementation returns a URL for the underlying class path resource, * if available. * @see java.lang.ClassLoader#getResource(String) * @see java.lang.Class#getResource(String) */ @Override public URL getURL() throws IOException { URL url = resolveURL(); if (url == null) { throw new FileNotFoundException( getDescription() + " cannot be resolved to URL because it does not exist"); } return url; } /** * This implementation creates a ClassPathResource, applying the given path * relative to the path of the underlying resource of this descriptor. * @see org.springframework.util.StringUtils#applyRelativePath(String, String) */ @Override public Resource createRelative(String relativePath) { String pathToUse = StringUtils.applyRelativePath(this.path, relativePath); return (this.clazz != null ? new ClassPathResource(pathToUse, this.clazz) : new ClassPathResource(pathToUse, this.classLoader)); } /** * This implementation returns the name of the file that this class path * 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 class path location. */ @Override public String getDescription() { StringBuilder builder = new StringBuilder("class path resource ["); String pathToUse = this.path; if (this.clazz != null && !pathToUse.startsWith("/")) { builder.append(ClassUtils.classPackageAsResourcePath(this.clazz)); builder.append('/'); } if (pathToUse.startsWith("/")) { pathToUse = pathToUse.substring(1); } builder.append(pathToUse); builder.append(']'); return builder.toString(); } /** * This implementation compares the underlying class path locations. */ @Override public boolean equals(@Nullable Object other) { if (this == other) { return true; } if (!(other instanceof ClassPathResource)) { return false; } ClassPathResource otherRes = (ClassPathResource) other; return (this.path.equals(otherRes.path) && ObjectUtils.nullSafeEquals(this.classLoader, otherRes.classLoader) && ObjectUtils.nullSafeEquals(this.clazz, otherRes.clazz)); } /** * This implementation returns the hash code of the underlying * class path location. */ @Override public int hashCode() { return this.path.hashCode(); } }