com.aspectran.core.util.ResourceUtils Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2022 The Aspectran Project
*
* 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 com.aspectran.core.util;
import com.aspectran.core.lang.Nullable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
/**
* A class to simplify access to ResourceUtils through the classloader.
*/
public class ResourceUtils {
/** Pseudo URL prefix for loading from the class path: "classpath:". */
public static final String CLASSPATH_URL_PREFIX = "classpath:";
/** URL prefix for loading from the file system: "file:". */
public static final String FILE_URL_PREFIX = "file:";
/** URL prefix for loading from a jar file: "jar:". */
public static final String JAR_URL_PREFIX = "jar:";
/** URL prefix for loading from a war file on Tomcat: "war:". */
public static final String WAR_URL_PREFIX = "war:";
/** URL protocol for a file in the file system: "file". */
public static final String URL_PROTOCOL_FILE = "file";
/** URL protocol for an entry from a jar file: "jar". */
public static final String URL_PROTOCOL_JAR = "jar";
/** URL protocol for an entry from a war file: "war". */
public static final String URL_PROTOCOL_WAR = "war";
/** URL protocol for an entry from a zip file: "zip". */
public static final String URL_PROTOCOL_ZIP = "zip";
/** URL protocol for an entry from a WebSphere jar file: "wsjar". */
public static final String URL_PROTOCOL_WSJAR = "wsjar";
/** URL protocol for an entry from a JBoss jar file: "vfszip". */
public static final String URL_PROTOCOL_VFSZIP = "vfszip";
/** URL protocol for a JBoss file system resource: "vfsfile". */
public static final String URL_PROTOCOL_VFSFILE = "vfsfile";
/** URL protocol for a general JBoss VFS resource: "vfs". */
public static final String URL_PROTOCOL_VFS = "vfs";
/** File extension for a regular jar file: ".jar". */
public static final String JAR_FILE_EXTENSION = ".jar";
/** Separator between JAR URL and file path within the JAR: "!/". */
public static final String JAR_URL_SEPARATOR = "!/";
/** Special separator between WAR URL and jar part on Tomcat. */
public static final String WAR_URL_SEPARATOR = "*/";
public static final String REGULAR_FILE_SEPARATOR = "/";
public static final char REGULAR_FILE_SEPARATOR_CHAR = '/';
/**
* Return whether the given resource location is a URL:
* either a special "classpath" pseudo URL or a standard URL.
* @param resourceLocation the location String to check
* @return whether the location qualifies as a URL
* @see #CLASSPATH_URL_PREFIX
* @see java.net.URL
*/
public static boolean isUrl(@Nullable String resourceLocation) {
if (resourceLocation == null) {
return false;
}
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
return true;
}
try {
new URL(resourceLocation);
return true;
} catch (MalformedURLException ex) {
return false;
}
}
/**
* Resolve the given resource location to a {@code java.net.URL}.
* Does not check whether the URL actually exists; simply returns
* the URL that the given location would correspond to.
* @param resourceLocation the resource location to resolve: either a
* "classpath:" pseudo URL, a "file:" URL, or a plain file path
* @return a corresponding URL object
* @throws FileNotFoundException if the resource cannot be resolved to a URL
*/
public static URL getURL(String resourceLocation) throws FileNotFoundException {
return getURL(resourceLocation, ClassUtils.getDefaultClassLoader());
}
/**
* Resolve the given resource location to a {@code java.net.URL}.
* Does not check whether the URL actually exists; simply returns
* the URL that the given location would correspond to.
* @param resourceLocation the resource location to resolve: either a
* "classpath:" pseudo URL, a "file:" URL, or a plain file path
* @param classLoader the class loader
* @return a corresponding URL object
* @throws FileNotFoundException if the resource cannot be resolved to a URL
*/
public static URL getURL(String resourceLocation, ClassLoader classLoader) throws FileNotFoundException {
Assert.notNull(resourceLocation, "Resource location must not be null");
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());
URL url = (classLoader != null ? classLoader.getResource(path) : ClassLoader.getSystemResource(path));
if (url == null) {
String description = "class path resource [" + path + "]";
throw new FileNotFoundException(description +
" cannot be resolved to URL because it does not exist");
}
return url;
}
try {
// try URL
return new URL(resourceLocation);
} catch (MalformedURLException ex) {
// no URL -> treat as file path
try {
return new File(resourceLocation).toURI().toURL();
} catch (MalformedURLException ex2) {
throw new FileNotFoundException("Resource location [" + resourceLocation +
"] is neither a URL not a well-formed file path");
}
}
}
/**
* Resolve the given resource location to a {@code java.io.File},
* i.e. to a file in the file system.
* Does not check whether the file actually exists; simply returns
* the File that the given location would correspond to.
* @param resourceLocation the resource location to resolve: either a
* "classpath:" pseudo URL, a "file:" URL, or a plain file path
* @return a corresponding File object
* @throws FileNotFoundException if the resource cannot be resolved to
* a file in the file system
*/
public static File getFile(String resourceLocation) throws FileNotFoundException {
return getFile(resourceLocation, ClassUtils.getDefaultClassLoader());
}
/**
* Resolve the given resource location to a {@code java.io.File},
* i.e. to a file in the file system.
* Does not check whether the file actually exists; simply returns
* the File that the given location would correspond to.
* @param resourceLocation the resource location to resolve: either a
* "classpath:" pseudo URL, a "file:" URL, or a plain file path
* @param classLoader the class loader
* @return a corresponding File object
* @throws FileNotFoundException if the resource cannot be resolved to
* a file in the file system
*/
public static File getFile(String resourceLocation, ClassLoader classLoader) throws FileNotFoundException {
Assert.notNull(resourceLocation, "Resource location must not be null");
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());
String description = "class path resource [" + path + "]";
URL url = (classLoader != null ? classLoader.getResource(path) : ClassLoader.getSystemResource(path));
if (url == null) {
throw new FileNotFoundException(description +
" cannot be resolved to absolute file path because it does not exist");
}
return getFile(url, description);
}
try {
// try URL
return getFile(new URL(resourceLocation));
} catch (MalformedURLException ex) {
// no URL -> treat as file path
return new File(resourceLocation);
}
}
/**
* Resolve the given resource URL to a {@code java.io.File},
* i.e. to a file in the file system.
* @param resourceUrl the resource URL to resolve
* @return a corresponding File object
* @throws FileNotFoundException if the URL cannot be resolved to
* a file in the file system
*/
public static File getFile(URL resourceUrl) throws FileNotFoundException {
return getFile(resourceUrl, "URL");
}
/**
* Resolve the given resource URL to a {@code java.io.File},
* i.e. to a file in the file system.
* @param resourceUrl the resource URL to resolve
* @param description a description of the original resource that
* the URL was created for (for example, a class path location)
* @return a corresponding File object
* @throws FileNotFoundException if the URL cannot be resolved to
* a file in the file system
*/
public static File getFile(URL resourceUrl, String description) throws FileNotFoundException {
Assert.notNull(resourceUrl, "Resource URL must not be null");
if (!URL_PROTOCOL_FILE.equals(resourceUrl.getProtocol())) {
throw new FileNotFoundException(
description + " cannot be resolved to absolute file path " +
"because it does not reside in the file system: " + resourceUrl);
}
try {
return new File(toURI(resourceUrl).getSchemeSpecificPart());
} catch (URISyntaxException ex) {
// Fallback for URLs that are not valid URIs (should hardly ever happen).
return new File(resourceUrl.getFile());
}
}
/**
* Resolve the given resource URI to a {@code java.io.File},
* i.e. to a file in the file system.
* @param resourceUri the resource URI to resolve
* @return a corresponding File object
* @throws FileNotFoundException if the URL cannot be resolved to
* a file in the file system
*/
public static File getFile(URI resourceUri) throws FileNotFoundException {
return getFile(resourceUri, "URI");
}
/**
* Resolve the given resource URI to a {@code java.io.File},
* i.e. to a file in the file system.
* @param resourceUri the resource URI to resolve
* @param description a description of the original resource that
* the URI was created for (for example, a class path location)
* @return a corresponding File object
* @throws FileNotFoundException if the URL cannot be resolved to
* a file in the file system
*/
public static File getFile(URI resourceUri, String description) throws FileNotFoundException {
Assert.notNull(resourceUri, "Resource URI must not be null");
if (!URL_PROTOCOL_FILE.equals(resourceUri.getScheme())) {
throw new FileNotFoundException(
description + " cannot be resolved to absolute file path " +
"because it does not reside in the file system: " + resourceUri);
}
return new File(resourceUri.getSchemeSpecificPart());
}
/**
* Determine whether the given URL points to a resource in the file system,
* i.e. has protocol "file", "vfsfile" or "vfs".
* @param url the URL to check
* @return whether the URL has been identified as a file system URL
*/
public static boolean isFileURL(URL url) {
String protocol = url.getProtocol();
return (URL_PROTOCOL_FILE.equals(protocol) || URL_PROTOCOL_VFSFILE.equals(protocol) ||
URL_PROTOCOL_VFS.equals(protocol));
}
/**
* Determine whether the given URL points to a resource in a jar file.
* i.e. has protocol "jar", "war, ""zip", "vfszip" or "wsjar".
* @param url the URL to check
* @return whether the URL has been identified as a JAR URL
*/
public static boolean isJarURL(URL url) {
String protocol = url.getProtocol();
return (URL_PROTOCOL_JAR.equals(protocol) || URL_PROTOCOL_WAR.equals(protocol) ||
URL_PROTOCOL_ZIP.equals(protocol) || URL_PROTOCOL_VFSZIP.equals(protocol) ||
URL_PROTOCOL_WSJAR.equals(protocol));
}
/**
* Determine whether the given URL points to a jar file itself,
* that is, has protocol "file" and ends with the ".jar" extension.
* @param url the URL to check
* @return whether the URL has been identified as a JAR file URL
*/
public static boolean isJarFileURL(URL url) {
return (URL_PROTOCOL_FILE.equals(url.getProtocol()) &&
url.getPath().toLowerCase().endsWith(JAR_FILE_EXTENSION));
}
/**
* Extract the URL for the actual jar file from the given URL
* (which may point to a resource in a jar file or to a jar file itself).
* @param jarUrl the original URL
* @return the URL for the actual jar file
* @throws MalformedURLException if no valid jar file URL could be extracted
*/
public static URL extractJarFileURL(URL jarUrl) throws MalformedURLException {
String urlFile = jarUrl.getFile();
int separatorIndex = urlFile.indexOf(JAR_URL_SEPARATOR);
if (separatorIndex != -1) {
String jarFile = urlFile.substring(0, separatorIndex);
try {
return new URL(jarFile);
} catch (MalformedURLException ex) {
// Probably no protocol in original jar URL, like "jar:C:/mypath/myjar.jar".
// This usually indicates that the jar file resides in the file system.
if (!jarFile.startsWith("/")) {
jarFile = "/" + jarFile;
}
return new URL(FILE_URL_PREFIX + jarFile);
}
} else {
return jarUrl;
}
}
/**
* Extract the URL for the outermost archive from the given jar/war URL
* (which may point to a resource in a jar file or to a jar file itself).
* In the case of a jar file nested within a war file, this will return
* a URL to the war file since that is the one resolvable in the file system.
* @param jarUrl the original URL
* @return the URL for the actual jar file
* @throws MalformedURLException if no valid jar file URL could be extracted
* @see #extractJarFileURL(URL)
*/
public static URL extractArchiveURL(URL jarUrl) throws MalformedURLException {
String urlFile = jarUrl.getFile();
int endIndex = urlFile.indexOf(WAR_URL_SEPARATOR);
if (endIndex != -1) {
// Tomcat's "war:file:...mywar.war*/WEB-INF/lib/myjar.jar!/myentry.txt"
String warFile = urlFile.substring(0, endIndex);
if (URL_PROTOCOL_WAR.equals(jarUrl.getProtocol())) {
return new URL(warFile);
}
int startIndex = warFile.indexOf(WAR_URL_PREFIX);
if (startIndex != -1) {
return new URL(warFile.substring(startIndex + WAR_URL_PREFIX.length()));
}
}
// Regular "jar:file:...myjar.jar!/myentry.txt"
return extractJarFileURL(jarUrl);
}
/**
* Create a URI instance for the given URL,
* replacing spaces with "%20" URI encoding first.
* @param url the URL to convert into a URI instance
* @return the URI instance
* @throws URISyntaxException if the URL wasn't a valid URI
* @see java.net.URL#toURI()
*/
public static URI toURI(URL url) throws URISyntaxException {
return toURI(url.toString());
}
/**
* Create a URI instance for the given location String,
* replacing spaces with "%20" URI encoding first.
* @param location the location String to convert into a URI instance
* @return the URI instance
* @throws URISyntaxException if the location wasn't a valid URI
*/
public static URI toURI(String location) throws URISyntaxException {
return new URI(StringUtils.replace(location, " ", "%20"));
}
/**
* Returns the URL of the resource on the classpath.
* @param resource the resource to find
* @return {@code URL} object for reading the resource;
* {@code null} if the resource could not be found
* @throws IOException if the resource cannot be found or read
*/
public static URL getResource(String resource) throws IOException {
return getResource(resource, ClassUtils.getDefaultClassLoader());
}
/**
* Returns the URL of the resource on the classpath.
* @param classLoader the class loader used to load the resource
* @param resource the resource to find
* @return {@code URL} object for reading the resource;
* {@code null} if the resource could not be found
* @throws IOException if the resource cannot be found or read
*/
public static URL getResource(String resource, ClassLoader classLoader) throws IOException {
URL url = null;
if (classLoader != null) {
url = classLoader.getResource(resource);
}
if (url == null) {
url = ClassLoader.getSystemResource(resource);
}
if (url == null) {
throw new IOException("Could not find resource '" + resource + "'");
}
return url;
}
public static File getResourceAsFile(String resource) throws IOException {
return getFile(getResource(resource));
}
public static File getResourceAsFile(String resource, ClassLoader classLoader) throws IOException {
return getFile(getResource(resource, classLoader));
}
/**
* Returns a resource on the classpath as a Stream object.
* @param resource the resource to find
* @return an input stream for reading the resource;
* {@code null} if the resource could not be found
* @throws IOException if the resource cannot be found or read
*/
public static InputStream getResourceAsStream(String resource) throws IOException {
return getResourceAsStream(resource, ClassUtils.getDefaultClassLoader());
}
/**
* Returns a resource on the classpath as a Stream object.
* @param resource the resource to find
* @param classLoader the class loader
* @return an input stream for reading the resource;
* {@code null} if the resource could not be found
* @throws IOException if the resource cannot be found or read
*/
public static InputStream getResourceAsStream(String resource, ClassLoader classLoader) throws IOException {
InputStream stream = null;
if (classLoader != null) {
stream = classLoader.getResourceAsStream(resource);
}
if (stream == null) {
stream = ClassLoader.getSystemResourceAsStream(resource);
}
if (stream == null) {
throw new IOException("Could not find resource " + resource);
}
return stream;
}
/**
* Returns a Reader for reading the specified file.
* @param file the file
* @param encoding the encoding
* @return the reader instance
* @throws IOException if an error occurred when reading resources using any I/O operations
*/
public static Reader getReader(final File file, String encoding) throws IOException {
InputStream stream;
try {
stream = AccessController.doPrivileged((PrivilegedExceptionAction)()
-> new FileInputStream(file));
} catch (PrivilegedActionException e) {
throw (IOException)e.getException();
}
Reader reader;
if (encoding != null) {
reader = new InputStreamReader(stream, encoding);
} else {
reader = new InputStreamReader(stream);
}
return reader;
}
/**
* Returns a Reader for reading the specified url.
* @param url the url
* @param encoding the encoding
* @return the reader instance
* @throws IOException if an error occurred when reading resources using any I/O operations
*/
public static Reader getReader(final URL url, String encoding) throws IOException {
InputStream stream;
try {
stream = AccessController.doPrivileged((PrivilegedExceptionAction)() -> {
InputStream is = null;
if (url != null) {
URLConnection connection = url.openConnection();
if (connection != null) {
// Disable caches to get fresh data for reloading.
connection.setUseCaches(false);
is = connection.getInputStream();
}
}
return is;
});
} catch (PrivilegedActionException e) {
throw (IOException)e.getException();
}
Reader reader;
if (encoding != null) {
reader = new InputStreamReader(stream, encoding);
} else {
reader = new InputStreamReader(stream);
}
return reader;
}
/**
* Returns a string from the specified file.
* @param file the file
* @param encoding the encoding
* @return the reader instance
* @throws IOException if an error occurred when reading resources using any I/O operations
*/
public static String read(File file, String encoding) throws IOException {
Reader reader = getReader(file, encoding);
String source;
try {
source = read(reader);
} finally {
reader.close();
}
return source;
}
/**
* Returns a string from the specified url.
* @param url the url
* @param encoding the encoding
* @return the string
* @throws IOException if an error occurred when reading resources using any I/O operations
*/
public static String read(URL url, String encoding) throws IOException {
Reader reader = getReader(url, encoding);
String source;
try {
source = read(reader);
} finally {
reader.close();
}
return source;
}
/**
* Returns a string from the specified Reader object.
* @param reader the reader
* @return the string
* @throws IOException if an error occurred when reading resources using any I/O operations
*/
public static String read(Reader reader) throws IOException {
final char[] buffer = new char[1024];
StringBuilder sb = new StringBuilder();
int len;
while ((len = reader.read(buffer)) != -1) {
sb.append(buffer, 0, len);
}
return sb.toString();
}
}