org.springframework.boot.devtools.restart.server.RestartServer.java Source code

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Here is the source code for org.springframework.boot.devtools.restart.server.RestartServer.java

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/*
 * Copyright 2012-2015 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.server;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.LinkedHashSet;
import java.util.Map.Entry;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.boot.devtools.restart.Restarter;
import org.springframework.boot.devtools.restart.classloader.ClassLoaderFile;
import org.springframework.boot.devtools.restart.classloader.ClassLoaderFile.Kind;
import org.springframework.boot.devtools.restart.classloader.ClassLoaderFiles;
import org.springframework.boot.devtools.restart.classloader.ClassLoaderFiles.SourceFolder;
import org.springframework.util.Assert;
import org.springframework.util.FileCopyUtils;
import org.springframework.util.ResourceUtils;

/**
 * Server used to {@link Restarter restart} the current application with updated
 * {@link ClassLoaderFiles}.
 *
 * @author Phillip Webb
 * @since 1.3.0
 */
public class RestartServer {

    private static final Log logger = LogFactory.getLog(RestartServer.class);

    private final SourceFolderUrlFilter sourceFolderUrlFilter;

    private final ClassLoader classLoader;

    /**
     * Create a new {@link RestartServer} instance.
     * @param sourceFolderUrlFilter the source filter used to link remote folder to the
     * local classpath
     */
    public RestartServer(SourceFolderUrlFilter sourceFolderUrlFilter) {
        this(sourceFolderUrlFilter, Thread.currentThread().getContextClassLoader());
    }

    /**
     * Create a new {@link RestartServer} instance.
     * @param sourceFolderUrlFilter the source filter used to link remote folder to the
     * local classpath
     * @param classLoader the application classloader
     */
    public RestartServer(SourceFolderUrlFilter sourceFolderUrlFilter, ClassLoader classLoader) {
        Assert.notNull(sourceFolderUrlFilter, "SourceFolderUrlFilter must not be null");
        Assert.notNull(classLoader, "ClassLoader must not be null");
        this.sourceFolderUrlFilter = sourceFolderUrlFilter;
        this.classLoader = classLoader;
    }

    /**
     * Update the current running application with the specified {@link ClassLoaderFiles}
     * and trigger a reload.
     * @param files updated class loader files
     */
    public void updateAndRestart(ClassLoaderFiles files) {
        Set<URL> urls = new LinkedHashSet<URL>();
        Set<URL> classLoaderUrls = getClassLoaderUrls();
        for (SourceFolder folder : files.getSourceFolders()) {
            for (Entry<String, ClassLoaderFile> entry : folder.getFilesEntrySet()) {
                for (URL url : classLoaderUrls) {
                    if (updateFileSystem(url, entry.getKey(), entry.getValue())) {
                        urls.add(url);
                    }
                }
            }
            urls.addAll(getMatchingUrls(classLoaderUrls, folder.getName()));
        }
        updateTimeStamp(urls);
        restart(urls, files);
    }

    private boolean updateFileSystem(URL url, String name, ClassLoaderFile classLoaderFile) {
        if (!isFolderUrl(url.toString())) {
            return false;
        }
        try {
            File folder = ResourceUtils.getFile(url);
            File file = new File(folder, name);
            if (file.exists() && file.canWrite()) {
                if (classLoaderFile.getKind() == Kind.DELETED) {
                    return file.delete();
                }
                FileCopyUtils.copy(classLoaderFile.getContents(), file);
                return true;
            }
        } catch (IOException ex) {
            // Ignore
        }
        return false;
    }

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

    private Set<URL> getMatchingUrls(Set<URL> urls, String sourceFolder) {
        Set<URL> matchingUrls = new LinkedHashSet<URL>();
        for (URL url : urls) {
            if (this.sourceFolderUrlFilter.isMatch(sourceFolder, url)) {
                if (logger.isDebugEnabled()) {
                    logger.debug("URL " + url + " matched against source folder " + sourceFolder);
                }
                matchingUrls.add(url);
            }
        }
        return matchingUrls;
    }

    private Set<URL> getClassLoaderUrls() {
        Set<URL> urls = new LinkedHashSet<URL>();
        ClassLoader classLoader = this.classLoader;
        while (classLoader != null) {
            if (classLoader instanceof URLClassLoader) {
                for (URL url : ((URLClassLoader) classLoader).getURLs()) {
                    urls.add(url);
                }
            }
            classLoader = classLoader.getParent();
        }
        return urls;

    }

    private void updateTimeStamp(Iterable<URL> urls) {
        for (URL url : urls) {
            updateTimeStamp(url);
        }
    }

    private void updateTimeStamp(URL url) {
        try {
            URL actualUrl = ResourceUtils.extractJarFileURL(url);
            File file = ResourceUtils.getFile(actualUrl, "Jar URL");
            file.setLastModified(System.currentTimeMillis());
        } catch (Exception ex) {
            // Ignore
        }
    }

    /**
     * Called to restart the application.
     * @param urls the updated URLs
     * @param files the updated files
     */
    protected void restart(Set<URL> urls, ClassLoaderFiles files) {
        Restarter restarter = Restarter.getInstance();
        restarter.addUrls(urls);
        restarter.addClassLoaderFiles(files);
        restarter.restart();
    }

}