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/*
* Copyright 2002-2012 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 spark.resource;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import spark.utils.Assert;
import spark.utils.ClassUtils;
import spark.utils.StringUtils;
/**
* {@link Resource} implementation for class path resources.
* Uses either a given ClassLoader or a given Class for loading resources.
* 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
* @see ClassLoader#getResourceAsStream(String)
* @see Class#getResourceAsStream(String)
* Code copied from Spring source. Modifications made (mostly removal of methods) by Per Wendel.
*/
public class ClassPathResource extends AbstractFileResolvingResource {
private final String path;
private ClassLoader classLoader;
private Class clazz;
/**
* Create a new ClassPathResource for ClassLoader usage.
* A leading slash will be removed, as the ClassLoader
* resource access methods will not accept it.
*
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 spark.utils.ClassUtils#getDefaultClassLoader()
*/
public ClassPathResource(String path) {
this(path, null);
}
/**
* Create a new ClassPathResource for 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, 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 ClassPathResource with optional ClassLoader and 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
*/
protected ClassPathResource(String path, ClassLoader classLoader, 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).
*
* @return the path
*/
public final String getPath() {
return this.path;
}
/**
* This implementation checks for the resolution of a resource URL.
*
* @see java.lang.ClassLoader#getResource(String)
* @see java.lang.Class#getResource(String)
*
* @return if exists.
*/
@Override
public boolean exists() {
URL url;
if (this.clazz != null) {
url = this.clazz.getResource(this.path);
} else {
url = this.classLoader.getResource(this.path);
}
return (url != null);
}
/**
* This implementation opens an InputStream for the given class path resource.
*
* @see java.lang.ClassLoader#getResourceAsStream(String)
* @see java.lang.Class#getResourceAsStream(String)
*
* @return the input stream.
*/
@Override
public InputStream getInputStream() throws IOException {
InputStream is;
if (this.clazz != null) {
is = this.clazz.getResourceAsStream(this.path);
} else {
is = this.classLoader.getResourceAsStream(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.
*
* @see java.lang.ClassLoader#getResource(String)
* @see java.lang.Class#getResource(String)
*
* @return the url.
*/
@Override
public URL getURL() throws IOException {
URL url;
if (this.clazz != null) {
url = this.clazz.getResource(this.path);
} else {
url = this.classLoader.getResource(this.path);
}
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 spark.utils.StringUtils#applyRelativePath(String, String)
*
* @return the resource.
*/
@Override
public Resource createRelative(String relativePath) {
String pathToUse = StringUtils.applyRelativePath(this.path, relativePath);
return new ClassPathResource(pathToUse, this.classLoader, this.clazz);
}
/**
* This implementation returns the name of the file that this class path
* resource refers to.
*
* @see spark.utils.StringUtils#getFilename(String)
*
* @return the file name.
*/
@Override
public String getFilename() {
return StringUtils.getFilename(this.path);
}
/**
* This implementation returns a description that includes the class path location.
*
* @return the description.
*/
@Override
public String getDescription() {
StringBuilder builder = new StringBuilder("class path resource [");
String pathToUse = 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.
*
* @return if equals.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof ClassPathResource) {
ClassPathResource otherRes = (ClassPathResource) obj;
ClassLoader thisLoader = this.classLoader;
ClassLoader otherLoader = otherRes.classLoader;
return (this.path.equals(otherRes.path) &&
thisLoader.equals(otherLoader) &&
this.clazz.equals(otherRes.clazz));
}
return false;
}
/**
* This implementation returns the hash code of the underlying
* class path location.
*
* @return the hash code.
*/
@Override
public int hashCode() {
return this.path.hashCode();
}
}