Java tutorial
/* * Copyright 2002-2003,2009 The Apache Software Foundation. * * 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.opensymphony.xwork2.util; import com.opensymphony.xwork2.util.logging.Logger; import com.opensymphony.xwork2.util.logging.LoggerFactory; import org.apache.commons.io.FileUtils; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.net.URISyntaxException; import java.net.URL; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.jar.JarFile; import java.util.zip.ZipEntry; /** * FileManager * <p/> * This class was brought in from oscore trunk revision 147. * * @author Jason Carreira * Created May 7, 2003 8:44:26 PM */ public class FileManager { //~ Static fields/initializers ///////////////////////////////////////////// private static Logger LOG = LoggerFactory.getLogger(FileManager.class); private static Map<String, Revision> files = Collections.synchronizedMap(new HashMap<String, Revision>()); protected static boolean reloadingConfigs = true; private static final String JAR_FILE_NAME_SEPARATOR = "!/"; private static final String JAR_FILE_EXTENSION_END = ".jar/"; //~ Constructors /////////////////////////////////////////////////////////// private FileManager() { } //~ Methods //////////////////////////////////////////////////////////////// public static void setReloadingConfigs(boolean reloadingConfigs) { FileManager.reloadingConfigs = reloadingConfigs; } public static boolean isReloadingConfigs() { return reloadingConfigs; } public static boolean fileNeedsReloading(String fileName, Class clazz) { URL fileUrl = ClassLoaderUtil.getResource(fileName, clazz); return fileUrl != null && fileNeedsReloading(fileUrl.toString()); } public static boolean fileNeedsReloading(String fileName) { Revision revision = files.get(fileName); if (revision == null) { // no revision yet and we keep the revision history, so // return whether the file needs to be loaded for the first time return reloadingConfigs; } return revision.needsReloading(); } /** * Loads opens the named file and returns the InputStream * * @param fileName - the name of the file to open * @return an InputStream of the file contents or null * @throws IllegalArgumentException if there is no file with the given file name */ public static InputStream loadFile(String fileName, Class clazz) { URL fileUrl = ClassLoaderUtil.getResource(fileName, clazz); return loadFile(fileUrl); } /** * Loads opens the named file and returns the InputStream * * @param fileUrl - the URL of the file to open * @return an InputStream of the file contents or null * @throws IllegalArgumentException if there is no file with the given file name */ public static InputStream loadFile(URL fileUrl) { return loadFile(fileUrl, true); } /** * Loads opens the named file and returns the InputStream * * @param fileUrl - the URL of the file to open * @param openStream - if true, open an InputStream to the file and return it * @return an InputStream of the file contents or null * @throws IllegalArgumentException if there is no file with the given file name */ public static InputStream loadFile(URL fileUrl, boolean openStream) { if (fileUrl == null) { return null; } String fileName = fileUrl.toString(); InputStream is = null; if (openStream) { try { is = fileUrl.openStream(); if (is == null) { throw new IllegalArgumentException("No file '" + fileName + "' found as a resource"); } } catch (IOException e) { throw new IllegalArgumentException("No file '" + fileName + "' found as a resource"); } } if (isReloadingConfigs()) { Revision revision; if (LOG.isDebugEnabled()) { LOG.debug("Creating revision for URL: " + fileName); } if (URLUtil.isJBoss5Url(fileUrl)) { revision = JBossFileRevision.build(fileUrl); } else if (URLUtil.isJarURL(fileUrl)) { revision = JarEntryRevision.build(fileUrl); } else { revision = FileRevision.build(fileUrl); } if (revision == null) { files.put(fileName, Revision.build(fileUrl)); } else { files.put(fileName, revision); } } return is; } //~ Inner Classes ////////////////////////////////////////////////////////// /** * Class represents common revsion resource, should be used as default class when no other option exists */ private static class Revision { public Revision() { } public boolean needsReloading() { return false; } public static Revision build(URL fileUrl) { return new Revision(); } } /** * Represents file resource revision, used for file://* resources */ private static class FileRevision extends Revision { private File file; private long lastModified; public FileRevision(File file, long lastUpdated) { if (file == null) { throw new IllegalArgumentException("File cannot be null"); } this.file = file; this.lastModified = lastUpdated; } public File getFile() { return file; } public void setLastModified(long lastModified) { this.lastModified = lastModified; } public long getLastModified() { return lastModified; } public boolean needsReloading() { return this.lastModified < this.file.lastModified(); } public static Revision build(URL fileUrl) { File file; try { file = new File(fileUrl.toURI()); } catch (URISyntaxException e) { file = new File(fileUrl.getPath()); } catch (Throwable t) { return null; } if (file.exists() && file.canRead()) { long lastModified = file.lastModified(); return new FileRevision(file, lastModified); } return null; } } /** * Represents file resource revision, used for vfszip://* resources */ private static class JBossFileRevision extends FileRevision { public JBossFileRevision(File file, long lastUpdated) { super(file, lastUpdated); } public static Revision build(URL fileUrl) { File file; URL url = URLUtil.normalizeToFileProtocol(fileUrl); try { if (url != null) { file = new File(url.toURI()); } else { return null; } } catch (URISyntaxException e) { file = new File(url.getPath()); } if (file.exists() && file.canRead()) { long lastModified = file.lastModified(); return new FileRevision(file, lastModified); } return null; } } /** * Represents jar resurce revision, used for jar://* resource */ private static class JarEntryRevision extends Revision { private String jarFileName; private String fileNameInJar; private long lastModified; public JarEntryRevision(String jarFileName, String fileNameInJar, long lastModified) { if ((jarFileName == null) || (fileNameInJar == null)) { throw new IllegalArgumentException("JarFileName and FileNameInJar cannot be null"); } this.jarFileName = jarFileName; this.fileNameInJar = fileNameInJar; this.lastModified = lastModified; } public boolean needsReloading() { ZipEntry entry; try { JarFile jarFile = new JarFile(this.jarFileName); entry = jarFile.getEntry(this.fileNameInJar); } catch (IOException e) { entry = null; } return entry != null && (lastModified < entry.getTime()); } public static Revision build(URL fileUrl) { // File within a Jar // Find separator index of jar filename and filename within jar String jarFileName = ""; try { String fileName = fileUrl.toString(); int separatorIndex = fileName.indexOf(JAR_FILE_NAME_SEPARATOR); if (separatorIndex == -1) { separatorIndex = fileName.lastIndexOf(JAR_FILE_EXTENSION_END); } if (separatorIndex == -1) { if (LOG.isWarnEnabled()) { LOG.warn("Could not find end of jar file!"); } return null; } // Split file name jarFileName = fileName.substring(0, separatorIndex); int index = separatorIndex + JAR_FILE_NAME_SEPARATOR.length(); String fileNameInJar = fileName.substring(index).replaceAll("%20", " "); URL url = URLUtil.normalizeToFileProtocol(fileUrl); if (url != null) { JarFile jarFile = new JarFile(FileUtils.toFile(url)); ZipEntry entry = jarFile.getEntry(fileNameInJar); return new JarEntryRevision(jarFileName.toString(), fileNameInJar, entry.getTime()); } else { return null; } } catch (Throwable e) { if (LOG.isWarnEnabled()) { LOG.warn("Could not create JarEntryRevision for [" + jarFileName + "]!", e); } return null; } } } }