Marco Zanini

I probably found out why WatchDog is missing some events when I add a directory containing a bunch of files, the problem is that the new directory has to be registered and in the meantime some events are gone. What can I do?

Hi to all, I'm using jsch to operate on remote filesystems with sftp. The only problem is that I have to cancel a directory that have files in it but jsch (sftp?) cannot cancel non-empty directories. Is there a way to do it or do I have to memorize the entire remote filesystem in order to be able to cancel contained files?

Any hints?

Thank you

Hi to all, I'm developing a program in order to recursively watch a directory for changes. The program works fine but when I copy a directory with a lot of files inside some of them are just missed and the overflow event is never raised. Here's my code, the watchDog puts every event in a blockinQueue read by the farmer.

/** * Recursively watches a directory for changes, notifies the server when a change happens. * @author Marco * */ public class WatchDog implements Runnable{ private boolean run; private WatchService watcher; private Path baseDir; private boolean trace; private HashMap<WatchKey,Path> keys; private HashSet<Path> directories; private BlockingQueue<UpdateEvent> queue; public WatchDog(BlockingQueue<UpdateEvent> q , Path baseDir) throws InstantiationException { this.baseDir = baseDir; System.out.println("[WD] The base directory is: " + this.baseDir); this.keys = new HashMap<WatchKey, Path>(); this.directories = new HashSet<Path>(); this.queue = q; this.run = true; } public void run() { System.out.println("[WD] Starting..."); try { this.watchChanges(); } catch (InterruptedException e1) { System.out.println("[WD] Interrupted"); e1.printStackTrace(); } while (this.run) { synchronized(this){ try { this.wait(); } catch (InterruptedException e) { e.printStackTrace(); System.out.println("[WD] Interrupted"); return; } } } System.out.println("[WD] Shutting down."); } //Recursively register baseDir then look for changes private void watchChanges() throws InterruptedException{ System.out.println("[WD] Watching directory " + this.baseDir + " for changes"); this.watcher = null; // 1) Create a WatchService for the file system System.out.println("[WD] Initializing watcher..."); try { this.watcher = FileSystems.getDefault().newWatchService(); } catch (IOException e) {e.printStackTrace();} if(watcher==null){ System.out.println("[WD] Ops something went wrong: watcher is null!"); return; } try { this.registerAll(this.baseDir); } catch (IOException e) {e.printStackTrace();} //Enable trace after initial registration this.trace = true; // 3) Infinite loop to wait for incoming events. When an event occurs, the key is signaled and // placed into the Watcher's queue. while (this.run) { // 4) Retrieve the key from the watcher's queue //wait for key to be signaled WatchKey key; try { key = watcher.take(); } catch (InterruptedException x) {return;} // Retrieves the directory associated with this key Path dir = keys.get(key); if (dir == null) { System.out.println("WatchKey not recognized!!"); continue; } // 5) Retrieve each pending event for the key for (WatchEvent<?> event: key.pollEvents()) { WatchEvent.Kind<?> kind = event.kind(); //The fileName is the context of the event WatchEvent<Path> ev = cast(event); Path filename = ev.context(); if (kind == ENTRY_CREATE && filename!=null) { if(Files.isDirectory(dir.resolve(filename) ) ){ try { this.register( dir.resolve(filename) ); } catch (IOException e) { e.printStackTrace(); } this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_DIRECTORY_ADDED)); } else { this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_FILE_ADDED)); } continue; } else if (kind == ENTRY_DELETE && filename!=null) { System.out.println("[WD] Control if it's a directory"); Iterator<Path> itr = this.directories.iterator(); boolean directory = false; while(itr.hasNext()){ Path item = itr.next(); if( item.compareTo(dir.resolve(filename))==0 ){ System.out.println("[WD] Deleted file is a directory!"); directory=true; } } if( directory ){ this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_DIRECTORY_DELETED)); } else { this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_FILE_DELETED)); } continue; } else if (kind == ENTRY_MODIFY && filename!=null) { if(Files.isDirectory( dir.resolve(filename) ) ){ this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_DIRECTORY_CHANGED)); } else { this.queue.put(new UpdateEvent(dir.resolve(filename), CommandProtocol.MESSAGE_FILE_CHANGED)); } continue; } if (kind == OVERFLOW) { System.out.println("[WD] Ops, maybe I lost some events!"); continue; } } // 6) Reset the key -- this step is critical if you want to receive //further watch events. If the key is no longer valid, the directory //is inaccessible so exit the loop. boolean valid = key.reset(); if (!valid) { keys.remove(key); // all directories are inaccessible if (keys.isEmpty()) { break; } } } } /**Register the given directory, and all its sub-directories, with the * WatchService. * * @param start Root path to start from * @throws IOException */ private void registerAll(final Path start) throws IOException { // register directory and sub-directories SimpleFileVisitor<Path> directoryRegister = new SimpleFileVisitor<Path>() { @Override public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attr) throws IOException { System.out.println("[WD] Calling register..."); register(dir); return FileVisitResult.CONTINUE; } }; System.out.println("[WD] Calling walkFileTree..."); Files.walkFileTree(start, directoryRegister); } /**Register the given directory with the WatchService * * @param dir Absolute Path of the directory to register * @throws IOException */ private void register(Path dir) throws IOException { if(watcher==null) System.out.println("[WD] Ops something went wrong: watcher is null!"); // 2) For each directory that you want to be monitored, register it with the watcher. You receive a WatchKey // instance for each directory that you register. WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY); this.directories.add(dir); if (trace) { Path prev = keys.get(key); if (prev == null) { System.out.println("[WD] Registering new directory: " + dir); } else { if (!dir.equals(prev)) { System.out.println("Update registration: from " + prev + " to " + dir); } } } System.out.println("[WD] Registering directory: " + dir); keys.put(key, dir); } @SuppressWarnings("unchecked") private static WatchEvent<Path> cast(WatchEvent<?> event) { return (WatchEvent<Path>)event; } //Method to stop the thread public void shutdown() { this.run = false; synchronized (this){ this.notifyAll(); } } }

This is the Farmer:
public class Farmer { private BlockingQueue<UpdateEvent> q; public Farmer(){ System.out.println("Creation of the farmer...."); } public boolean lookFor(String dir){ System.out.println("Initialize WatchDog with directory: " + dir); Path dirPath = Paths.get(dir); //Create the Queue this.q = new LinkedBlockingQueue<UpdateEvent>(); try { WatchDog wd = new WatchDog(this, this.q, dirPath); System.out.println("Starting WatchDog!"); new Thread(wd).start(); this.waitForChanges(); } catch (InstantiationException e) { System.out.println("Error creating the WatchDog!"); e.printStackTrace(); } return false; } private void waitForChanges(){ while(true){ try { UpdateEvent item = (UpdateEvent) this.q.take(); if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_DIRECTORY_ADDED)){ System.out.println("[Farmer] Directory " + item.getFile() + " added, propagating change..."); } else if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_FILE_ADDED)){ System.out.println("[Farmer] File " + item.getFile() + " added, propagating change..."); }else if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_DIRECTORY_DELETED)){ System.out.println("[Farmer] Directory " + item.getFile() + " deleted, propagating change..."); } else if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_FILE_DELETED)){ System.out.println("[Farmer] File " + item.getFile() + " deleted, propagating change..."); } else if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_DIRECTORY_CHANGED)){ System.out.println("[Farmer] Directory " + item.getFile() + " modified, propagating change..."); } else if(item.getType().equalsIgnoreCase(CommandProtocol.MESSAGE_FILE_CHANGED)){ System.out.println("[Farmer] File " + item.getFile() + " modified, propagating change..."); } } catch (InterruptedException e) { System.out.println("[Farmer] Interrupted!"); e.printStackTrace(); } } } }

Has anyone tried to use this service and had similar problems? I searched trough the internet but wasn't able to find anything.

Thanks

Hi to all, I'm experiencing problems building a jar file with maven using Eclipse plugin, this is the log:

[DEBUG] After assembly is interpolated:

<?xml version="1.0"?>
<assembly xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd"
xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<id>bin</id>
<formats>
<format>zip</format>
</formats>
<fileSets>
<fileSet>
<outputDirectory>/doc</outputDirectory>
<directory>doc/</directory>
</fileSet>
<fileSet>
<outputDirectory>/doc/api</outputDirectory>
<directory>target/site/apidocs</directory>
</fileSet>
</fileSets>
</assembly>



[DEBUG] All known ContainerDescriptorHandler components: [plexus, metaInf-spring, file-aggregator, metaInf-services]
[DEBUG] FileSet[doc/] dir perms: -1 file perms: -1
[DEBUG] The archive base directory is 'null'
[DEBUG] FileSet[doc/api/] dir perms: -1 file perms: -1
[DEBUG] The archive base directory is 'null'
[DEBUG] Cannot find ArtifactResolver with hint: project-cache-aware
org.codehaus.plexus.component.repository.exception.ComponentLookupException: java.util.NoSuchElementException
role: org.apache.maven.artifact.resolver.ArtifactResolver
roleHint: project-cache-aware
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:253)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:229)
at org.apache.maven.shared.repository.DefaultRepositoryAssembler.contextualize(DefaultRepositoryAssembler.java:721)
at org.codehaus.plexus.PlexusLifecycleManager.contextualize(PlexusLifecycleManager.java:264)
at org.codehaus.plexus.PlexusLifecycleManager.manageLifecycle(PlexusLifecycleManager.java:240)
at org.codehaus.plexus.PlexusLifecycleManager.manageDeferredLifecycles(PlexusLifecycleManager.java:216)
at org.codehaus.plexus.PlexusLifecycleManager.manage(PlexusLifecycleManager.java:141)
at org.sonatype.guice.plexus.binders.PlexusBeanBinder.afterInjection(PlexusBeanBinder.java:75)
at com.google.inject.internal.MembersInjectorImpl.notifyListeners(MembersInjectorImpl.java:97)
at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:95)
at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:254)
at com.google.inject.internal.InjectorImpl$4$1.call(InjectorImpl.java:968)
at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1021)
at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:964)
at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1003)
at org.sonatype.guice.bean.reflect.AbstractDeferredClass.get(AbstractDeferredClass.java:48)
at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1021)
at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
at com.google.inject.Scopes$1$1.get(Scopes.java:59)
at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
at com.google.inject.internal.InjectorImpl$4$1.call(InjectorImpl.java:968)
at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1014)
at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:964)
at org.sonatype.guice.bean.locators.LazyBeanEntry.getValue(LazyBeanEntry.java:80)
at org.sonatype.guice.plexus.locators.LazyPlexusBean.getValue(LazyPlexusBean.java:50)
at org.sonatype.guice.bean.locators.EntryListAdapter$ValueIterator.next(EntryListAdapter.java:113)
at org.apache.maven.plugin.assembly.archive.DefaultAssemblyArchiver.createArchive(DefaultAssemblyArchiver.java:187)
at org.apache.maven.plugin.assembly.mojos.AbstractAssemblyMojo.execute(AbstractAssemblyMojo.java:413)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:534)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: java.util.NoSuchElementException
at java.util.AbstractList$Itr.next(AbstractList.java:350)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:249)
... 50 more
[DEBUG] No dependency sets specified.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 11.774s
[INFO] Finished at: Tue Mar 13 09:20:25 GMT 2012
[INFO] Final Memory: 10M/25M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-assembly-plugin:2.2.1:attached (make-assembly) on project scamall: Failed to create assembly: Error creating assembly archive bin: You must set at least one file. -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-assembly-plugin:2.2.1:attached (make-assembly) on project scamall: Failed to create assembly: Error creating assembly archive bin: You must set at least one file.
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:534)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: Failed to create assembly: Error creating assembly archive bin: You must set at least one file.
at org.apache.maven.plugin.assembly.mojos.AbstractAssemblyMojo.execute(AbstractAssemblyMojo.java:472)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
... 19 more
Caused by: org.apache.maven.plugin.assembly.archive.ArchiveCreationException: Error creating assembly archive bin: You must set at least one file.
at org.apache.maven.plugin.assembly.archive.DefaultAssemblyArchiver.createArchive(DefaultAssemblyArchiver.java:196)
at org.apache.maven.plugin.assembly.mojos.AbstractAssemblyMojo.execute(AbstractAssemblyMojo.java:413)
... 21 more
Caused by: org.codehaus.plexus.archiver.ArchiverException: You must set at least one file.
at org.codehaus.plexus.archiver.zip.AbstractZipArchiver.createArchiveMain(AbstractZipArchiver.java:272)
at org.codehaus.plexus.archiver.zip.AbstractZipArchiver.execute(AbstractZipArchiver.java:250)
at org.codehaus.plexus.archiver.AbstractArchiver.createArchive(AbstractArchiver.java:871)
at org.apache.maven.plugin.assembly.archive.archiver.AssemblyProxyArchiver.createArchive(AssemblyProxyArchiver.java:512)
at org.apache.maven.plugin.assembly.archive.DefaultAssemblyArchiver.createArchive(DefaultAssemblyArchiver.java:192)
... 22 more
[ERROR]
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

My pom.xml is:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>lero.idp.localhost</groupId> <artifactId>scamall</artifactId> <version>0.1</version> <packaging>jar</packaging> <name>Scamall</name> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <repositories> <repository> <id>shib-release</id> <url>https://shibboleth.net/nexus/content/groups/public</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> <repository> <id>shib-snapshot</id> <url>https://shibboleth.net/nexus/content/repositories/snapshots</url> <releases> <enabled>false</enabled> </releases> </repository> </repositories> <dependencies> <!-- Compile dependencies --> <dependency> <groupId>edu.internet2.middleware</groupId> <artifactId>shibboleth-identityprovider</artifactId> <version>2.3.0</version> </dependency> <!-- Provided dependencies --> <!-- Runtime dependencies --> <!-- Test dependencies --> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.2</version> <configuration> <source>1.6</source> <target>1.6</target> <debug>true</debug> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-assembly-plugin</artifactId> <version>2.2.1</version> <configuration> <descriptors> <descriptor>src/main/assembly/bin.xml</descriptor> </descriptors> </configuration> <executions> <execution> <id>make-assembly</id> <phase>package</phase> <goals> <goal>attached</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-source-plugin</artifactId> <version>2.1.2</version> <executions> <execution> <id>attach-sources</id> <goals> <goal>jar</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-javadoc-plugin</artifactId> <version>2.7</version> <executions> <execution> <id>attach-javadocs</id> <goals> <goal>jar</goal> </goals> </execution> </executions> <configuration> <links> <link>http://download.oracle.com/javase/6/docs/api/</link> </links> <quiet>true</quiet> <author>false</author> <version>true</version> <doctitle>${project.name} ${project.version} Java API</doctitle> <windowtitle>${project.name} ${project.version} Java API</windowtitle> </configuration> </plugin> </plugins> </build> <description>Personalized LoginHandler to get User Context</description> </project>

Thank you to everybody!

Well, after trying it for a while I can say it works great! Authenticating the user trough the LDAP local directory and then accessing Google Apps on the cloud is great!

Cheers

So, I have to be sorry again, many times one thinks things are well explained but it's wrong.

So I have an application running on a web server on my machine. I want to obtain access to google services using oAuth. So I have to make a request to the Google server with some parameters and read the parameter in the response which is embedded in the title of the page. This is because for authoriing the application the user is redirected to an url that asks him for permissions and then Google redirects the browser to the webpage which title I have to examine.

I hope now everything is clear, thank you for your patience.

Oh sorry, I need to acquire it with my application without user intervention.

You ask google for an authorization code and google will provide you one embedded in the title of the page. You should save it and send it again to google together with other parameters to get an access token.

Authorization code is passed as code when you send it to Google. I think that this phrase in that link leaves no doubts: "The authorization code can be returned to your application in the title bar of the browser or to an http://localhost port in the query string."

Because of this: http://code.google.com/intl/it-IT/apis/accounts/docs/OAuth2InstalledApp.html Look under the section "Choosing a redirect URI"

Hi to all,
I need to get a parameter who's inside the title of a web page. I am using servlets and java. How can I do? I suppose I should wait for the page to load too.

Many thanks!

Thank you, I'll give it a try! And then let you know if it works good.

Hi to all, I'm trying to implement an application on google app engine and I want to be able to manage the identity of my users. I want to use SAML and I found some interesting projects like: http://www.forgerock.com/openam.html. Anyway, now I can't deploy the WAR because the uploader from google fails in compiling some files. Do you know other good choices to manage user's identity? Should I try another way?

Yes but I have to use Google App Engine. Thanks anyway.

Thank you, really fast! So I am wondering why it doesn't succeeds, sometimes the error is for a file missing, sometimes for a wrong method call. Maybe when you upload a war the server isn't supposed to do all the checks that the GAE upoader does (for example check if all the jsp files can be compiled).