/*
* Copyright 2012-2017 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 org.springframework.boot.web.servlet.server;
import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarFile;
/**
* Logic to extract URLs of static resource jars (those containing
* {@code "META-INF/resources"} directories).
*
* @author Andy Wilkinson
* @author Phillip Webb
*/
class StaticResourceJars {
public final List<URL> getUrls() {
ClassLoader classLoader = getClass().getClassLoader();
List<URL> urls = new ArrayList<>();
if (classLoader instanceof URLClassLoader) {
for (URL url : ((URLClassLoader) classLoader).getURLs()) {
addUrl(urls, url);
}
}
return urls;
}
private void addUrl(List<URL> urls, URL url) {
try {
if ("file".equals(url.getProtocol())) {
addUrlFile(urls, url, new File(url.getFile()));
}
else {
addUrlConnection(urls, url, url.openConnection());
}
}
catch (IOException ex) {
throw new IllegalStateException(ex);
}
}
private void addUrlFile(List<URL> urls, URL url, File file) {
if (file.isDirectory() && new File(file, "META-INF/resources").isDirectory()) {
urls.add(url);
}
else if (isResourcesJar(file)) {
urls.add(url);
}
}
private void addUrlConnection(List<URL> urls, URL url, URLConnection connection) {
if (connection instanceof JarURLConnection) {
if (isResourcesJar((JarURLConnection) connection)) {
urls.add(url);
}
}
}
private boolean isResourcesJar(JarURLConnection connection) {
try {
return isResourcesJar(connection.getJarFile());
}
catch (IOException ex) {
return false;
}
}
private boolean isResourcesJar(File file) {
try {
return isResourcesJar(new JarFile(file));
}
catch (IOException ex) {
return false;
}
}
private boolean isResourcesJar(JarFile jar) throws IOException {
try {
return jar.getName().endsWith(".jar")
&& (jar.getJarEntry("META-INF/resources") != null);
}
finally {
jar.close();
}
}
}