How to set up a chrooted Debian Environment on Fritz!Box Fon WLAN 7390

Setting up a chrooted Debian Environment on the Fritz!Box 7390 allows you to run almost any software on your Fritz!Box (at least, if it’s compatible with the box’ MIPS CPU). These instructions shouldn’t harm your Fritz!Box if you follow them carefully – however, there’s no warranty, you do it on your own risk. Continue reading How to set up a chrooted Debian Environment on Fritz!Box Fon WLAN 7390

How to use Apache HttpClient (DefaultHttpClient) with HTTPS/SSL on Android

Connecting to an HTTPS address using the Apache HttpClient shipped with Android is not so straight forward. Whether the server’s certificate as correct or not, you will probably see one of these exceptions:

javax.net.ssl.SSLPeerUnverifiedException: No peer certificate.

Continue reading How to use Apache HttpClient (DefaultHttpClient) with HTTPS/SSL on Android

Creating & Parsing WBXML with Java using kXML 2

WBXML (WAP Binary XML) is a binary representation of XML. It is used e.g. by the Microsoft Exchange ActiveSync protocol.

Only very few WBXML parsers for Java seem to be available. One of the libraries you will probably come across when searching for a WBXML Java Library is kXML. kXML is a small XML pull parser, specially designed for constrained environments such as Applets, Personal Java or MIDP devices (see kXML’s about page).

Getting started with kXML is a bit tricky, since you find only a handful of tutorials that are suitable for kXML 2. These snippets should make it easier for you. Continue reading Creating & Parsing WBXML with Java using kXML 2

Android SDK with 64bit Java SE Development Kit (JDK)

The Android SDK installer (r10 in my case) doesn’t support the 64bit version of the Java SE Development Kit (JDK) out of the box. You will see an error message such as “Java SE Development Kit (JDK) not found”.

Instead of installing the 32bit version of JDK, try the following workaround that I’ve found in the codearetoy blog. Continue reading Android SDK with 64bit Java SE Development Kit (JDK)

Outlook Web Access 2010: HTTP 500 Error after authentication

If you experience HTTP 500 Errors after logging in to Microsoft Outlook Web Access (OWA) powered by Microsoft’s Exchange Server 2010 SP1, you should check if the service “Microsoft Exchange Forms-Based Authentication” (in German versions: “Formularbasierter Microsoft Exchange-Authentifizierungsdienst”, MSExchangeFBA) is running. If it’s not, start it and change the run option to “Automatic (delayed run)”.

Error 0x80070021 when using lighttpd’s WebDAV with Windows 7

When trying to use WebDAV provided by a lighttpd installation with Windows 7, you will probably encounter the following error message when copying files to the WebDAV folder:

Error 0x80070021: The process cannot acess the file because another process has locked a portion of the file. Continue reading Error 0x80070021 when using lighttpd’s WebDAV with Windows 7

Tomcat & Apache: High CPU Usage

Summary: Tomcat running behing an Apache Frontend Server can cause high CPU Usage on the Java Process. Here are several approaches how to fix it.


Setup: Debian GNU/Linux, Java Runtime Environment (JRE) 1.6, Apache 2.2, Tomcat 6.0.29, mod_jk/mod_proxy


Effect: Accessing web applications directly through Tomcat doesn’t cause any problems. When accessing web applications through the Apache Frontend Server (forwarding requests by using mod_proxy), it took a few seconds and the cpu usage of the Java process went up to 99.9 %. Obviously, the combination of Apache and Tomcat is causing this problem. Continue reading Tomcat & Apache: High CPU Usage