Jetzt wo Jetty 7 zu Eclipse gewandert ist und auch immer modularer wird, schwindet meine Euphorie gegenüber dem Projekt. Das liegt an drei Gründen.

1. Viele Jars. Um nur ein einfaches Servlet servieren zu können sind nötig: jetty-continuations (warum es hie eine Abhängigkeit gibt ist mir Schleierhaft), jetty-http, jetty-io, jetty-security, jetty-server, jetty-servlet, jetty-util. (Man kann das auch als ein großes Jar auch den Maven Rep. holen.)
2. Umzug nach Eclipse. Durch den Umzug nach Eclipse befinden sich Dokus aus verschiedenen Servern. Es fehlt eine klare Anlaufstelle mit und vollständiger Doku.
3. API-Änderungen. Nicht nur der Paketnamen ändert sich, sondern auch ein paar Methoden. Das ist an sich nichts problematisch, ab wenn eben mit Punkt 2 die Dokus nicht immer auf dem neusten Stand sind, nervt das.

Zusammenfassend für ein Servlet:

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.*;

public class StartJetty
{
  public static void main( String[] args ) throws Exception
  {
    Server server = new Server( 8080 );

    ServletContextHandler context = new ServletContextHandler( server, "/" );
    context.addServlet( new ServletHolder( new HiServlet() ), "/*" );
    server.start();
    server.join();
  }
}

class HiServlet extends HttpServlet
{
  protected void doGet( HttpServletRequest request, HttpServletResponse response )
      throws ServletException, IOException
  {
    response.setContentType( "text/html" );
    response.setStatus( HttpServletResponse.SC_OK );
    response.getWriter().println( "Hi" );
  }
}

Lösung mit iText:

String path = "lala.pdf";
PdfReader pdfReader = new PdfReader( path );

for ( int page = 1; page <= pdfReader.getNumberOfPages(); page++ )
{
  String textFromPage = PdfTextExtractor.getTextFromPage( pdfReader, page );
}

Lösung mit PDFBox:

String path = "lala.pdf";
PDDocument pdfDocument = PDDocument.load( path );
String textFromPage = new PDFTextStripper().getText( pdfDocument );
pdfDocument.close();

Das Ergebnis unterscheidet sich deutlich, die PDFBox gibt bessere Ergebnisse.

Interessant zu lesen, wie Last.fm Java (und auch C++) in ihrem Backend nutzt: http://java.dzone.com/articles/case-study-how-lastfm-uses. HornetQ ist die JMS-Implementierung von JBoss 6.

Aus http://commons.apache.org/lang/article3_0.html:

What’s new in Commons Lang 3.0?

Commons Lang 3.0 is (not yet) out, and the obvious question is: "So what? What’s changed?".

The big story

Lang is now Java 5 based. We’ve generified the API, moved certain APIs to support varargsand thrown out any features that are now supported by Java itself. We’ve removed the deprecated parts of the API and have also removed some features that were deemed weak or unnecessary. All of this means that Lang 3.0 is not backwards compatible.

To that end we have changed the package name, allowing Lang 3.0 to sit side-by-side with your previous version of Lang without any bad side effects. The new package name is the exciting and original org.apache.commons.lang3.

There are also, as you’d expect, new features, enhancements and bugs fixed.

The build

We built 3.0 using Maven 2.2.1 and Java 1.5. Needs confirmation before release of actual build details

Migrating from 2.x

Despite the label of backwards incompatibility, in the vast majority of cases the simple addition of a '3' to an import statement will suffice for your migration. For example, using Perl:

find . -type f -name ‚*.java‘ | xargs perl -pi -e ’s/org\.apache\.commons\.lang\./org.apache.commons.lang3./g‘

Maven users will need to update the groupId from commons-lang to org.apache.commons, and the artifactId from commons-lang to commons-lang3.

What’s gone?

Enum package – Java 5 provided enums out of the box, therefore we dispensed with both the deprecated enum package, and the enums package. Instead you should migrate over to the standard Java enum. An EnumUtils class has been born from the ashes of the old code, focused on providing additional functionality to the standard Java enum API.

NestedExceptions – In Java 1.4, the notion that all Throwables could be linked to a cause was introduced. In Lang we had provided a NestedException framework to support the same feature, and now that we’re jumping from Java 1.3 to Java 5 we are remove this feature. The deprecation section below covers one part of ExceptionUtils that remains until we are on Java 6, where the last remaining parts of the JDK appear to have embraced the new cause API.

JVMRandom – This class was introduced in Lang 2.0 to support a Random object built around the system seed. This proved to be both an uncommon use case and one with bugs and so was dropped.

StringEscapeUtils.escapeSql – This was a misleading method, only handling the simplest of possible SQL cases. As SQL is not Lang’s focus, it didn’t make sense to improve this method.

Various Exception classes were removed – the lesson in defining more semantically relevant exception classes is that you can keep on coming up with more and more new classes. Simpler to focus on using the main JDK classes.

The various Range classes in the math package were removed in favour of a new Range class.

All deprecated fields/methods/classes – with a new major version, all of the previously deprecated parts of the API could finally go away.

If you feel that something was unfairly taken away, please feel free to contact the list. In many cases the possibility exists to reintroduce code.

Deprecations

The lone deprecation in 3.0 is that of the notion of ‚cause method names‘ in ExceptionUtils. In Java 5.0 it is still just about needed to handle some JDK classes that have not been migrated to the getCause API. In Java 6.0 things appear to be resolved and we will remove the related methods in Lang 4.0.

New packages

Two new packages have shown up. org.apache.commons.lang3.concurrent, which unsurprisingly provides support classes for multi-threaded programming, and org.apache.commons.lang3.text.translate, which provides a pluggable API for text transformation.

TODO: Add examples

New classes

CharSequenceUtils

EnumUtils

Pair

Range

builder.Builder

exception.ContextedException

exception.CloneFailedException

reflect.ConstructorUtils

reflect.FieldUtils

reflect.MethodUtils

reflect.TypeUtils

text.WordUtils

New methods

What’s fixed in Lang 3.0?

Weitere Änderungen: http://commons.apache.org/lang/upgradeto3_0.html.

So und wann kommt nun Common Collections für Java 5?

Wenn man von Spring kommt ist man gewöhnt, dass es ein Lebenszyklus gibt insbesondere mit

• @PostConstruct

Standardmäßig gibt es das mit Guice nicht und das ist ziemlich ungünstig, insbesondere wenn man Spring-Projekte migrieren möchte. (Siehe Diskussion http://code.google.com/p/google-guice/issues/detail?id=62)

Allerdings gibt es http://code.google.com/p/guiceyfruit/. Das bildet den Lebenszkylus, vorgeschrieben durch Annotationen (http://code.google.com/p/guiceyfruit/wiki/Annotations), nach. Es wird einfach als Modul mit hinzugenommen, etwa so:

Injector injector = Guice.createInjector( new Jsr250Module(), new MEINModule() );

Mit paketsichtbaren Methoden gibt es aber Probleme: Sie müssen public sein.