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package sun.misc;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.Enumeration;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.jar.Attributes;
import java.util.jar.Attributes.Name;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;
import java.security.PrivilegedActionException;
import java.net.URL;
import java.net.MalformedURLException;
import sun.net.www.ParseUtil;

This class checks dependent extensions a particular jar file may have declared through its manifest attributes.

Jar file declared dependent extensions through the extension-list attribute. The extension-list contains a list of keys used to fetch the other attributes describing the required extension. If key is the extension key declared in the extension-list attribute, the following describing attribute can be found in the manifest : key-Extension-Name: (Specification package name) key-Specification-Version: (Specification-Version) key-Implementation-Version: (Implementation-Version) key-Implementation-Vendor-Id: (Imlementation-Vendor-Id) key-Implementation-Version: (Implementation version) key-Implementation-URL: (URL to download the requested extension)

This class also maintain versioning consistency of installed extensions dependencies declared in jar file manifest.

Author: Jerome Dochez
/** * <p> * This class checks dependent extensions a particular jar file may have * declared through its manifest attributes. * </p> * Jar file declared dependent extensions through the extension-list * attribute. The extension-list contains a list of keys used to * fetch the other attributes describing the required extension. * If key is the extension key declared in the extension-list * attribute, the following describing attribute can be found in * the manifest : * key-Extension-Name: (Specification package name) * key-Specification-Version: (Specification-Version) * key-Implementation-Version: (Implementation-Version) * key-Implementation-Vendor-Id: (Imlementation-Vendor-Id) * key-Implementation-Version: (Implementation version) * key-Implementation-URL: (URL to download the requested extension) * <p> * This class also maintain versioning consistency of installed * extensions dependencies declared in jar file manifest. * </p> * @author Jerome Dochez */
public class ExtensionDependency { /* Callbak interfaces to delegate installation of missing extensions */ private static Vector<ExtensionInstallationProvider> providers;

Register an ExtensionInstallationProvider. The provider is responsible for handling the installation (upgrade) of any missing extensions.

Params:
  • eip – ExtensionInstallationProvider implementation
/** * <p> * Register an ExtensionInstallationProvider. The provider is responsible * for handling the installation (upgrade) of any missing extensions. * </p> * @param eip ExtensionInstallationProvider implementation */
public synchronized static void addExtensionInstallationProvider (ExtensionInstallationProvider eip) { if (providers == null) { providers = new Vector<>(); } providers.add(eip); }

Unregister a previously installed installation provider

/** * <p> * Unregister a previously installed installation provider * </p> */
public synchronized static void removeExtensionInstallationProvider (ExtensionInstallationProvider eip) { providers.remove(eip); }

Checks the dependencies of the jar file on installed extension.

Params:
  • jarFile – containing the attriutes declaring the dependencies
/** * <p> * Checks the dependencies of the jar file on installed extension. * </p> * @param jarFile containing the attriutes declaring the dependencies */
public static boolean checkExtensionsDependencies(JarFile jar) { if (providers == null) { // no need to bother, nobody is registered to install missing // extensions return true; } try { ExtensionDependency extDep = new ExtensionDependency(); return extDep.checkExtensions(jar); } catch (ExtensionInstallationException e) { debug(e.getMessage()); } return false; } /* * Check for all declared required extensions in the jar file * manifest. */ protected boolean checkExtensions(JarFile jar) throws ExtensionInstallationException { Manifest man; try { man = jar.getManifest(); } catch (IOException e) { return false; } if (man == null) { // The applet does not define a manifest file, so // we just assume all dependencies are satisfied. return true; } boolean result = true; Attributes attr = man.getMainAttributes(); if (attr != null) { // Let's get the list of declared dependencies String value = attr.getValue(Name.EXTENSION_LIST); if (value != null) { StringTokenizer st = new StringTokenizer(value); // Iterate over all declared dependencies while (st.hasMoreTokens()) { String extensionName = st.nextToken(); debug("The file " + jar.getName() + " appears to depend on " + extensionName); // Sanity Check String extName = extensionName + "-" + Name.EXTENSION_NAME.toString(); if (attr.getValue(extName) == null) { debug("The jar file " + jar.getName() + " appers to depend on " + extensionName + " but does not define the " + extName + " attribute in its manifest "); } else { if (!checkExtension(extensionName, attr)) { debug("Failed installing " + extensionName); result = false; } } } } else { debug("No dependencies for " + jar.getName()); } } return result; } /* * <p> * Check that a particular dependency on an extension is satisfied. * </p> * @param extensionName is the key used for the attributes in the manifest * @param attr is the attributes of the manifest file * * @return true if the dependency is satisfied by the installed extensions */ protected synchronized boolean checkExtension(final String extensionName, final Attributes attr) throws ExtensionInstallationException { debug("Checking extension " + extensionName); if (checkExtensionAgainstInstalled(extensionName, attr)) return true; debug("Extension not currently installed "); ExtensionInfo reqInfo = new ExtensionInfo(extensionName, attr); return installExtension(reqInfo, null); } /* * <p> * Check if a particular extension is part of the currently installed * extensions. * </p> * @param extensionName is the key for the attributes in the manifest * @param attr is the attributes of the manifest * * @return true if the requested extension is already installed */ boolean checkExtensionAgainstInstalled(String extensionName, Attributes attr) throws ExtensionInstallationException { File fExtension = checkExtensionExists(extensionName); if (fExtension != null) { // Extension already installed, just check against this one try { if (checkExtensionAgainst(extensionName, attr, fExtension)) return true; } catch (FileNotFoundException e) { debugException(e); } catch (IOException e) { debugException(e); } return false; } else { // Not sure if extension is already installed, so check all the // installed extension jar files to see if we get a match File[] installedExts; try { // Get the list of installed extension jar files so we can // compare the installed versus the requested extension installedExts = getInstalledExtensions(); } catch(IOException e) { debugException(e); return false; } for (int i=0;i<installedExts.length;i++) { try { if (checkExtensionAgainst(extensionName, attr, installedExts[i])) return true; } catch (FileNotFoundException e) { debugException(e); } catch (IOException e) { debugException(e); // let's continue with the next installed extension } } } return false; } /* * <p> * Check if the requested extension described by the attributes * in the manifest under the key extensionName is compatible with * the jar file. * </p> * * @param extensionName key in the attribute list * @param attr manifest file attributes * @param file installed extension jar file to compare the requested * extension against. */ protected boolean checkExtensionAgainst(String extensionName, Attributes attr, final File file) throws IOException, FileNotFoundException, ExtensionInstallationException { debug("Checking extension " + extensionName + " against " + file.getName()); // Load the jar file ... Manifest man; try { man = AccessController.doPrivileged( new PrivilegedExceptionAction<Manifest>() { public Manifest run() throws IOException, FileNotFoundException { if (!file.exists()) throw new FileNotFoundException(file.getName()); JarFile jarFile = new JarFile(file); return jarFile.getManifest(); } }); } catch(PrivilegedActionException e) { if (e.getException() instanceof FileNotFoundException) throw (FileNotFoundException) e.getException(); throw (IOException) e.getException(); } // Construct the extension information object ExtensionInfo reqInfo = new ExtensionInfo(extensionName, attr); debug("Requested Extension : " + reqInfo); int isCompatible = ExtensionInfo.INCOMPATIBLE; ExtensionInfo instInfo = null; if (man != null) { Attributes instAttr = man.getMainAttributes(); if (instAttr != null) { instInfo = new ExtensionInfo(null, instAttr); debug("Extension Installed " + instInfo); isCompatible = instInfo.isCompatibleWith(reqInfo); switch(isCompatible) { case ExtensionInfo.COMPATIBLE: debug("Extensions are compatible"); return true; case ExtensionInfo.INCOMPATIBLE: debug("Extensions are incompatible"); return false; default: // everything else debug("Extensions require an upgrade or vendor switch"); return installExtension(reqInfo, instInfo); } } } return false; } /* * <p> * An required extension is missing, if an ExtensionInstallationProvider is * registered, delegate the installation of that particular extension to it. * </p> * * @param reqInfo Missing extension information * @param instInfo Older installed version information * * @return true if the installation is successful */ protected boolean installExtension(ExtensionInfo reqInfo, ExtensionInfo instInfo) throws ExtensionInstallationException { Vector<ExtensionInstallationProvider> currentProviders; synchronized(providers) { @SuppressWarnings("unchecked") Vector<ExtensionInstallationProvider> tmp = (Vector<ExtensionInstallationProvider>) providers.clone(); currentProviders = tmp; } for (Enumeration<ExtensionInstallationProvider> e = currentProviders.elements(); e.hasMoreElements();) { ExtensionInstallationProvider eip = e.nextElement(); if (eip!=null) { // delegate the installation to the provider if (eip.installExtension(reqInfo, instInfo)) { debug(reqInfo.name + " installation successful"); Launcher.ExtClassLoader cl = (Launcher.ExtClassLoader) Launcher.getLauncher().getClassLoader().getParent(); addNewExtensionsToClassLoader(cl); return true; } } } // We have tried all of our providers, noone could install this // extension, we just return failure at this point debug(reqInfo.name + " installation failed"); return false; }

Checks if the extension, that is specified in the extension-list in the applet jar manifest, is already installed (i.e. exists in the extension directory).

Params:
  • extensionName – extension name in the extension-list
Returns:the extension if it exists in the extension directory
/** * <p> * Checks if the extension, that is specified in the extension-list in * the applet jar manifest, is already installed (i.e. exists in the * extension directory). * </p> * * @param extensionName extension name in the extension-list * * @return the extension if it exists in the extension directory */
private File checkExtensionExists(String extensionName) { // Function added to fix bug 4504166 final String extName = extensionName; final String[] fileExt = {".jar", ".zip"}; return AccessController.doPrivileged( new PrivilegedAction<File>() { public File run() { try { File fExtension; File[] dirs = getExtDirs(); // Search the extension directories for the extension that is specified // in the attribute extension-list in the applet jar manifest for (int i=0;i<dirs.length;i++) { for (int j=0;j<fileExt.length;j++) { if (extName.toLowerCase().endsWith(fileExt[j])) { fExtension = new File(dirs[i], extName); } else { fExtension = new File(dirs[i], extName+fileExt[j]); } debug("checkExtensionExists:fileName " + fExtension.getName()); if (fExtension.exists()) { return fExtension; } } } return null; } catch(Exception e) { debugException(e); return null; } } }); }

Returns:the java.ext.dirs property as a list of directory

/** * <p> * @return the java.ext.dirs property as a list of directory * </p> */
private static File[] getExtDirs() { String s = java.security.AccessController.doPrivileged( new sun.security.action.GetPropertyAction("java.ext.dirs")); File[] dirs; if (s != null) { StringTokenizer st = new StringTokenizer(s, File.pathSeparator); int count = st.countTokens(); debug("getExtDirs count " + count); dirs = new File[count]; for (int i = 0; i < count; i++) { dirs[i] = new File(st.nextToken()); debug("getExtDirs dirs["+i+"] "+ dirs[i]); } } else { dirs = new File[0]; debug("getExtDirs dirs " + dirs); } debug("getExtDirs dirs.length " + dirs.length); return dirs; } /* * <p> * Scan the directories and return all files installed in those * </p> * @param dirs list of directories to scan * * @return the list of files installed in all the directories */ private static File[] getExtFiles(File[] dirs) throws IOException { Vector<File> urls = new Vector<File>(); for (int i = 0; i < dirs.length; i++) { String[] files = dirs[i].list(new JarFilter()); if (files != null) { debug("getExtFiles files.length " + files.length); for (int j = 0; j < files.length; j++) { File f = new File(dirs[i], files[j]); urls.add(f); debug("getExtFiles f["+j+"] "+ f); } } } File[] ua = new File[urls.size()]; urls.copyInto(ua); debug("getExtFiles ua.length " + ua.length); return ua; } /* * <p> * @return the list of installed extensions jar files * </p> */ private File[] getInstalledExtensions() throws IOException { return AccessController.doPrivileged( new PrivilegedAction<File[]>() { public File[] run() { try { return getExtFiles(getExtDirs()); } catch(IOException e) { debug("Cannot get list of installed extensions"); debugException(e); return new File[0]; } } }); } /* * <p> * Add the newly installed jar file to the extension class loader. * </p> * * @param cl the current installed extension class loader * * @return true if successful */ private Boolean addNewExtensionsToClassLoader(Launcher.ExtClassLoader cl) { try { File[] installedExts = getInstalledExtensions(); for (int i=0;i<installedExts.length;i++) { final File instFile = installedExts[i]; URL instURL = AccessController.doPrivileged( new PrivilegedAction<URL>() { public URL run() { try { return ParseUtil.fileToEncodedURL(instFile); } catch (MalformedURLException e) { debugException(e); return null; } } }); if (instURL != null) { URL[] urls = cl.getURLs(); boolean found=false; for (int j = 0; j<urls.length; j++) { debug("URL["+j+"] is " + urls[j] + " looking for "+ instURL); if (urls[j].toString().compareToIgnoreCase( instURL.toString())==0) { found=true; debug("Found !"); } } if (!found) { debug("Not Found ! adding to the classloader " + instURL); cl.addExtURL(instURL); } } } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); // let's continue with the next installed extension } return Boolean.TRUE; } // True to display all debug and trace messages static final boolean DEBUG = false; private static void debug(String s) { if (DEBUG) { System.err.println(s); } } private void debugException(Throwable e) { if (DEBUG) { e.printStackTrace(); } } }