org.springframework.core.io.UrlResource Maven / Gradle / Ivy
/*
* 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.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ResourceUtils;
import org.springframework.util.StringUtils;
/**
* {@link Resource} implementation for {@code java.net.URL} locators.
* Supports resolution as a {@code URL} and also as a {@code File} in
* case of the {@code "file:"} protocol.
*
* @author Juergen Hoeller
* @since 28.12.2003
* @see java.net.URL
*/
public class UrlResource extends AbstractFileResolvingResource {
/**
* Original URI, if available; used for URI and File access.
*/
@Nullable
private final URI uri;
/**
* Original URL, used for actual access.
*/
private final URL url;
/**
* Cleaned URL (with normalized path), used for comparisons.
*/
private final URL cleanedUrl;
/**
* Create a new {@code UrlResource} based on the given URI object.
* @param uri a URI
* @throws MalformedURLException if the given URL path is not valid
* @since 2.5
*/
public UrlResource(URI uri) throws MalformedURLException {
Assert.notNull(uri, "URI must not be null");
this.uri = uri;
this.url = uri.toURL();
this.cleanedUrl = getCleanedUrl(this.url, uri.toString());
}
/**
* Create a new {@code UrlResource} based on the given URL object.
* @param url a URL
*/
public UrlResource(URL url) {
Assert.notNull(url, "URL must not be null");
this.url = url;
this.cleanedUrl = getCleanedUrl(this.url, url.toString());
this.uri = null;
}
/**
* Create a new {@code UrlResource} based on a URL path.
* Note: The given path needs to be pre-encoded if necessary.
* @param path a URL path
* @throws MalformedURLException if the given URL path is not valid
* @see java.net.URL#URL(String)
*/
public UrlResource(String path) throws MalformedURLException {
Assert.notNull(path, "Path must not be null");
this.uri = null;
this.url = new URL(path);
this.cleanedUrl = getCleanedUrl(this.url, path);
}
/**
* Create a new {@code UrlResource} based on a URI specification.
*
The given parts will automatically get encoded if necessary.
* @param protocol the URL protocol to use (e.g. "jar" or "file" - without colon);
* also known as "scheme"
* @param location the location (e.g. the file path within that protocol);
* also known as "scheme-specific part"
* @throws MalformedURLException if the given URL specification is not valid
* @see java.net.URI#URI(String, String, String)
*/
public UrlResource(String protocol, String location) throws MalformedURLException {
this(protocol, location, null);
}
/**
* Create a new {@code UrlResource} based on a URI specification.
*
The given parts will automatically get encoded if necessary.
* @param protocol the URL protocol to use (e.g. "jar" or "file" - without colon);
* also known as "scheme"
* @param location the location (e.g. the file path within that protocol);
* also known as "scheme-specific part"
* @param fragment the fragment within that location (e.g. anchor on an HTML page,
* as following after a "#" separator)
* @throws MalformedURLException if the given URL specification is not valid
* @see java.net.URI#URI(String, String, String)
*/
public UrlResource(String protocol, String location, @Nullable String fragment) throws MalformedURLException {
try {
this.uri = new URI(protocol, location, fragment);
this.url = this.uri.toURL();
this.cleanedUrl = getCleanedUrl(this.url, this.uri.toString());
}
catch (URISyntaxException ex) {
MalformedURLException exToThrow = new MalformedURLException(ex.getMessage());
exToThrow.initCause(ex);
throw exToThrow;
}
}
/**
* Determine a cleaned URL for the given original URL.
* @param originalUrl the original URL
* @param originalPath the original URL path
* @return the cleaned URL
* @see org.springframework.util.StringUtils#cleanPath
*/
private URL getCleanedUrl(URL originalUrl, String originalPath) {
try {
return new URL(StringUtils.cleanPath(originalPath));
}
catch (MalformedURLException ex) {
// Cleaned URL path cannot be converted to URL
// -> take original URL.
return originalUrl;
}
}
/**
* This implementation opens an InputStream for the given URL.
*
It sets the {@code useCaches} flag to {@code false},
* mainly to avoid jar file locking on Windows.
* @see java.net.URL#openConnection()
* @see java.net.URLConnection#setUseCaches(boolean)
* @see java.net.URLConnection#getInputStream()
*/
@Override
public InputStream getInputStream() throws IOException {
URLConnection con = this.url.openConnection();
ResourceUtils.useCachesIfNecessary(con);
try {
return con.getInputStream();
}
catch (IOException ex) {
// Close the HTTP connection (if applicable).
if (con instanceof HttpURLConnection) {
((HttpURLConnection) con).disconnect();
}
throw ex;
}
}
/**
* This implementation returns the underlying URL reference.
*/
@Override
public URL getURL() {
return this.url;
}
/**
* This implementation returns the underlying URI directly,
* if possible.
*/
@Override
public URI getURI() throws IOException {
if (this.uri != null) {
return this.uri;
}
else {
return super.getURI();
}
}
@Override
public boolean isFile() {
if (this.uri != null) {
return super.isFile(this.uri);
}
else {
return super.isFile();
}
}
/**
* This implementation returns a File reference for the underlying URL/URI,
* provided that it refers to a file in the file system.
* @see org.springframework.util.ResourceUtils#getFile(java.net.URL, String)
*/
@Override
public File getFile() throws IOException {
if (this.uri != null) {
return super.getFile(this.uri);
}
else {
return super.getFile();
}
}
/**
* This implementation creates a {@code UrlResource}, applying the given path
* relative to the path of the underlying URL of this resource descriptor.
* @see java.net.URL#URL(java.net.URL, String)
*/
@Override
public Resource createRelative(String relativePath) throws MalformedURLException {
if (relativePath.startsWith("/")) {
relativePath = relativePath.substring(1);
}
return new UrlResource(new URL(this.url, relativePath));
}
/**
* This implementation returns the name of the file that this URL refers to.
* @see java.net.URL#getPath()
*/
@Override
public String getFilename() {
return StringUtils.getFilename(this.cleanedUrl.getPath());
}
/**
* This implementation returns a description that includes the URL.
*/
@Override
public String getDescription() {
return "URL [" + this.url + "]";
}
/**
* This implementation compares the underlying URL references.
*/
@Override
public boolean equals(Object other) {
return (this == other || (other instanceof UrlResource &&
this.cleanedUrl.equals(((UrlResource) other).cleanedUrl)));
}
/**
* This implementation returns the hash code of the underlying URL reference.
*/
@Override
public int hashCode() {
return this.cleanedUrl.hashCode();
}
}