... stellt gscan2pdf unter Linux her. Das Frontend vereint viele vorhandene Funktionen rund um das Digitalisieren von Dokumenten unter einer einfach zu bedienenden Oberfläche. Unter Ubuntu Hardy Heron lässt sich das ganze mit dem Befehl sudo aptitude -r install gscan2pdf mit allen Featueres installieren. Nun lassen sich die Seiten via tesseract-ocr in Text umwandeln. Das funktioniert zwar nicht fehlerfrei, reicht aber zum wiederfinden der Dateien mit Desktopsuchmaschinen wie Tracker.


Hier mal ein Beispiel um sich ein Bild von der Erkennungsqualität von Tesseract zu machen.


Erkannter Text:

Close Window
Print Stog
java Feature — Inheritance
H1erarch1es 1n JPA
The persistence model introduced in EJB 3.0 as a replacement for entity
beans is known as the Java Persistence API (JPA). The JPA borrows from both
proprietary and open source models, such as Oracle TopLink, Hibernate,
Spring, and other frameworks, which have gained traction as popular
alternatives to the often heavyweight and cumbersome persistence directives
required by earlier EJB revisions. Among the new features introduced in EJB
3.0 through theJPA is support for entity inheritance. In this article, we will
examine inheritance strategies supported by theJPA and apply these
strategies to a simple entity hierarchy, exploring the strengths and
weaknesses of each approach. This comparison is intended to help you
understand how to set up entity hierarchies, and to decide which mapping
approach to take for the entity hierarchies in your own application.
Mapping ]PA Entity Inheritance , ., . . , ....
Hierarchies _ _ __ _ [_ _
java has supported single-class inheritance - in W I Q *
which a non—interface class can extend a single Vty _ . — ¢
other class - since its inception. While it's been . `
common practice to exploit the code reuse and
polymorphism benefits of inheritance in many 2 ¤
areas of the business domain, data inheritance
hasn't been well handled in the EJB persistence domain until now. This has
been a major shortcoming, since in the real world, data is often hierarchical,
and the lack of standard, built-in support for the inheritance of data objects
has required countless workarounds and headaches. Leveraging the ease of
use of Java SE annotations, JPA delivers declarative support for defining and
mapping entity inheritance hierarchies, including abstract entities and
polymorphic relationships and queries.
]PA Entity Inheritance Mapping Strategies
JPA provides declarative support for three main implementation strategies
that dictate how the entities in a hierarchy map to underlying tables. To
illustrate how these three strategies are manifested in code, Figure 1 shows a
sample entity hierarchy that demonstrates both inheritance and polymorphic
5 26.05.2OOS