org.springframework.boot.devtools.restart.ChangeableUrls Maven / Gradle / Ivy

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/*
 * Copyright 2012-2016 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.devtools.restart;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

import org.springframework.boot.devtools.settings.DevToolsSettings;
import org.springframework.util.StringUtils;

/**
 * A filtered collection of URLs which can change after the application has started.
 *
 * @author Phillip Webb
 * @author Andy Wilkinson
 */
final class ChangeableUrls implements Iterable {

	private final List urls;

	private ChangeableUrls(URL... urls) {
		DevToolsSettings settings = DevToolsSettings.get();
		List reloadableUrls = new ArrayList(urls.length);
		for (URL url : urls) {
			if ((settings.isRestartInclude(url) || isFolderUrl(url.toString()))
					&& !settings.isRestartExclude(url)) {
				reloadableUrls.add(url);
			}
		}
		this.urls = Collections.unmodifiableList(reloadableUrls);
	}

	private boolean isFolderUrl(String urlString) {
		return urlString.startsWith("file:") && urlString.endsWith("/");
	}

	@Override
	public Iterator iterator() {
		return this.urls.iterator();
	}

	public int size() {
		return this.urls.size();
	}

	public URL[] toArray() {
		return this.urls.toArray(new URL[this.urls.size()]);
	}

	public List toList() {
		return Collections.unmodifiableList(this.urls);
	}

	@Override
	public String toString() {
		return this.urls.toString();
	}

	public static ChangeableUrls fromUrlClassLoader(URLClassLoader classLoader) {
		List urls = new ArrayList();
		for (URL url : classLoader.getURLs()) {
			urls.add(url);
			urls.addAll(getUrlsFromClassPathOfJarManifestIfPossible(url));
		}
		return fromUrls(urls);
	}

	private static List getUrlsFromClassPathOfJarManifestIfPossible(URL url) {
		JarFile jarFile = getJarFileIfPossible(url);
		if (jarFile != null) {
			try {
				return getUrlsFromClassPathAttribute(url, jarFile.getManifest());
			}
			catch (IOException ex) {
				throw new IllegalStateException(
						"Failed to read Class-Path attribute from manifest of jar " + url,
						ex);
			}
		}
		return Collections.emptyList();
	}

	private static JarFile getJarFileIfPossible(URL url) {
		try {
			File file = new File(url.toURI());
			if (file.isFile()) {
				return new JarFile(file);
			}
		}
		catch (Exception ex) {
			// Assume it's not a jar and continue
		}
		return null;
	}

	private static List getUrlsFromClassPathAttribute(URL base, Manifest manifest) {
		if (manifest == null) {
			return Collections.emptyList();
		}
		String classPathAttribute = manifest.getMainAttributes()
				.getValue(Attributes.Name.CLASS_PATH);
		if (!StringUtils.hasText(classPathAttribute)) {
			return Collections.emptyList();
		}
		List urls = new ArrayList();
		for (String entry : StringUtils.delimitedListToStringArray(classPathAttribute,
				" ")) {
			try {
				urls.add(new URL(base, entry));
			}
			catch (MalformedURLException ex) {
				throw new IllegalStateException(
						"Class-Path attribute contains malformed URL", ex);
			}
		}
		return urls;
	}

	public static ChangeableUrls fromUrls(Collection urls) {
		return fromUrls(new ArrayList(urls).toArray(new URL[urls.size()]));
	}

	public static ChangeableUrls fromUrls(URL... urls) {
		return new ChangeableUrls(urls);
	}

}