Advanced Apache Camel logging and best practices

28 Feb
2012

Apache Camel supports a mapped diagnostic context which can be used to improve log entries, but also there is a log component which makes it easier to create log entries. Together they can be used to create foundations of activity monitoring without need to deploy another tool or database.
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Apache Aries under Apache Tomcat

24 Jan
2012

Few months ago I’ve read an article written by my friend Jacek Laskowski – Enterprise OSGi runtime setup with Apache Aries Blueprint. In his article Jacek describes which bundles should be installed to get the blueprint working. As IBM employee Jacek can always promote IBM WebSphere in version X or Y which started (or will start) supporting blueprint as dependency injection mechanism. That’s not fine for these who do not run IBM producs and want something light. As you know, Aries and OSGi Blueprint is an alternative for old-fashion Spring approach. Read the rest of this entry »

Running aspects under OSGi 4.2 with Karaf

24 Nov
2011

One of bigest benefits of Java is byte code manipulation. You can change everything you want in your application without touching source code. That’s usefull for many cases, starting from legacy code, where we can’t simply modify and recompile library up to modern applications where aspects can be used to handle runtime exceptions. The most popular project is AspectJ which is part of Eclipse ecosystem, in this post I going to show you how to use AspectJ with Karaf.
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Preserving message order in ActiveMQ

18 Nov
2011

Few hours ago I’ve found an usefull post about preserving message order with ActiveMQ written by Marcelo Jabali from FUSE Source.

In his example Marcelo used broker feature called Exclusive Consumers. It lets send messages only to one consumer and if it fails then second consumer gets all messages. I think it is not the best idea if we have many messages to process. Why we wouldn’t use few consumers with preserved message order? Well, I was sure it is not possible, but during last training I’ve found solution.
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Introduction to Karaf WebConsole

17 Nov
2011

Management of OSGi – let’s face it – is not very hard. The OSGi environment is clearly defined and that gives programmers many mechanisms to create administrative tools. The problem begins when we would like to use only one tool to manage few projects or artifacts of different types. I know this from personal experience because when I run Camel, ActiveMQ and CXF every from them provides own administration console. Every of them requires own security configuration, looks differently, have own dependencies and so on.
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Karaf WebConsole – wprowadzenie

16 Nov
2011

Zarządzanie tym, co się dzieje z OSGi – powiedzmy sobie szczerze – nie jest bardzo trudne. Idee tego środowiska są zdefiniowane jasno co daje programistom do dyspozycji wiele mechanizmów do tworzenia narzędzi administracyjnych. Problem zaczyna się gdy chcemy użyć jednego narzędzia do zarządzania kilkoma projektami bądź artefaktami kilku typów. Znam to z autopsji, ponieważ gdy uruchamiam Camela, ActiveMQ i CXF to każde z nich dostarcza własną konsolę administracyjną. Każda z nich wymaga oddzielnej konfiguracji bezpieczeństwa, inaczej wygląda, ma swoje zależności i tak dalej.
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Building sample middleware – producer

18 Jun
2011
This entry is part 3 of 3 in the series Building sample middleware

Last two days I’ve spent hacking Swing code. I decided to run standalone producer application to show real interaction with broker. You may treat this Swing app like entry point for people to our middleware system. Users simply do “transfers” from this application and don’t know anything about technical details. I added text area to main window to show structure of message sent to broker.
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XML Schema Design Patterns

14 Jun
2011

XML Schema jest bodajże najlepszym sposobem walidacji dokumentów XML. Model zastosowany w przypadku tego meta-języka pozwala na tworzenie złożonych konstrukcji. W oparciu o niego można budować własne rozszerzenia czy też zagnieżdżać w sekcjach xsd:appinfo dodatkowe metadane. Dzisiaj jednak nie o tym, a o wzorcach projektowych. Sam się zdziwiłem gdy trafiłem na artykuł Introducing Design Patterns in XML Schemas. W życiu się nie zastanawiałem czy to co piszę w XSD ma coś wspólnego z wzorcami czy nie. Sun wyprzedził w tym momencie chyba wszystkich. :-)
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Building sample middleware – data structures

13 Jun
2011
This entry is part 2 of 3 in the series Building sample middleware

Data with middleware

The data structures are very important in middleware world. Because we often connect multiple systems we need to define an “domain model” for integration. The domain model means that objects we share between all systems are well known, well defined, well understand in multiple teams often provided by multiple vendors. Let see what does it means in practice.
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Building sample middleware – broker

10 Jun
2011
This entry is part 1 of 3 in the series Building sample middleware

At end of the May I had great time in United Kingdom providing consulting. After this I started thinking about sharing an idea of middleware application based on ActiveMQ and Camel features. I’ve spent few days to create sufficient example.

What middleware is?

Middleware is a general term, about some software which is some kind of proxy between other systems. What for? – you could ask. Generally because communication from point to point is not the best to build bigger applications, and some components in middle of communication allows us to inject new logic without changing source systems. Could you imagine situation where you have a number of system producing messages and an number of consumers of these messages written in different languages? That’s typical case where middleware is going to be usefull.
There is number of middleware tools from various categories, in this post we’ll learn how to use ActiveMQ to build message oriented middleware. What does the MOM means? Generally that we have asynchronous communication without direct method invocations. Producer don’t know anything about consumer and vice versa. If you are interested in MOM – pick up “ActiveMQ in Action” book (written by commiters of ActiveMQ) from Manning Publications Co. where this term is described in greater detail.
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