org.springframework.core.io.UrlResource Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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.io.UncheckedIOException;
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 java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
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
* @author Sam Brannen
* @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 String (with normalized path), used for comparisons.
*/
@Nullable
private volatile String cleanedUrl;
/**
* Create a new {@code UrlResource} based on the given URL object.
* @param url a URL
* @see #UrlResource(URI)
* @see #UrlResource(String)
*/
public UrlResource(URL url) {
Assert.notNull(url, "URL must not be null");
this.uri = null;
this.url = url;
}
/**
* 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();
}
/**
* 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");
// Equivalent without java.net.URL constructor - for building on JDK 20+
/*
try {
String cleanedPath = StringUtils.cleanPath(path);
this.uri = ResourceUtils.toURI(cleanedPath);
this.url = this.uri.toURL();
this.cleanedUrl = cleanedPath;
}
catch (URISyntaxException | IllegalArgumentException ex) {
MalformedURLException exToThrow = new MalformedURLException(ex.getMessage());
exToThrow.initCause(ex);
throw exToThrow;
}
*/
this.uri = null;
this.url = ResourceUtils.toURL(path);
this.cleanedUrl = StringUtils.cleanPath(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();
}
catch (URISyntaxException ex) {
MalformedURLException exToThrow = new MalformedURLException(ex.getMessage());
exToThrow.initCause(ex);
throw exToThrow;
}
}
/**
* Create a new {@code UrlResource} from the given {@link URI}.
*
This factory method is a convenience for {@link #UrlResource(URI)} that
* catches any {@link MalformedURLException} and rethrows it wrapped in an
* {@link UncheckedIOException}; suitable for use in {@link java.util.stream.Stream}
* and {@link java.util.Optional} APIs or other scenarios when a checked
* {@link IOException} is undesirable.
* @param uri a URI
* @throws UncheckedIOException if the given URL path is not valid
* @since 6.0
* @see #UrlResource(URI)
*/
public static UrlResource from(URI uri) throws UncheckedIOException {
try {
return new UrlResource(uri);
}
catch (MalformedURLException ex) {
throw new UncheckedIOException(ex);
}
}
/**
* Create a new {@code UrlResource} from the given URL path.
*
This factory method is a convenience for {@link #UrlResource(String)}
* that catches any {@link MalformedURLException} and rethrows it wrapped in an
* {@link UncheckedIOException}; suitable for use in {@link java.util.stream.Stream}
* and {@link java.util.Optional} APIs or other scenarios when a checked
* {@link IOException} is undesirable.
* @param path a URL path
* @throws UncheckedIOException if the given URL path is not valid
* @since 6.0
* @see #UrlResource(String)
*/
public static UrlResource from(String path) throws UncheckedIOException {
try {
return new UrlResource(path);
}
catch (MalformedURLException ex) {
throw new UncheckedIOException(ex);
}
}
/**
* Lazily determine a cleaned URL for the given original URL.
*/
private String getCleanedUrl() {
String cleanedUrl = this.cleanedUrl;
if (cleanedUrl != null) {
return cleanedUrl;
}
String originalPath = (this.uri != null ? this.uri : this.url).toString();
cleanedUrl = StringUtils.cleanPath(originalPath);
this.cleanedUrl = cleanedUrl;
return cleanedUrl;
}
/**
* 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();
customizeConnection(con);
try {
return con.getInputStream();
}
catch (IOException ex) {
// Close the HTTP connection (if applicable).
if (con instanceof HttpURLConnection httpConn) {
httpConn.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}, delegating to
* {@link #createRelativeURL(String)} for adapting the relative path.
* @see #createRelativeURL(String)
*/
@Override
public Resource createRelative(String relativePath) throws MalformedURLException {
return new UrlResource(createRelativeURL(relativePath));
}
/**
* This delegate creates a {@code java.net.URL}, applying the given path
* relative to the path of the underlying URL of this resource descriptor.
* A leading slash will get dropped; a "#" symbol will get encoded.
* @since 5.2
* @see #createRelative(String)
* @see ResourceUtils#toRelativeURL(URL, String)
*/
protected URL createRelativeURL(String relativePath) throws MalformedURLException {
if (relativePath.startsWith("/")) {
relativePath = relativePath.substring(1);
}
return ResourceUtils.toRelativeURL(this.url, relativePath);
}
/**
* This implementation returns the URL-decoded name of the file that this URL
* refers to.
* @see java.net.URL#getPath()
* @see java.net.URLDecoder#decode(String, java.nio.charset.Charset)
*/
@Override
@Nullable
public String getFilename() {
if (this.uri != null) {
// URI path is decoded and has standard separators
return StringUtils.getFilename(this.uri.getPath());
}
else {
String filename = StringUtils.getFilename(StringUtils.cleanPath(this.url.getPath()));
return (filename != null ? URLDecoder.decode(filename, StandardCharsets.UTF_8) : null);
}
}
/**
* This implementation returns a description that includes the URL.
*/
@Override
public String getDescription() {
return "URL [" + (this.uri != null ? this.uri : this.url) + "]";
}
/**
* This implementation compares the underlying URL references.
*/
@Override
public boolean equals(@Nullable Object other) {
return (this == other || (other instanceof UrlResource resource &&
getCleanedUrl().equals(resource.getCleanedUrl())));
}
/**
* This implementation returns the hash code of the underlying URL reference.
*/
@Override
public int hashCode() {
return getCleanedUrl().hashCode();
}
}