Wiki wettstein

Introduction

2011-10-24T22:22:46+02:00

Benefit of threads Risk of threads Safety Nothing bad ever happens. Race conditions are examples of unsafe programms. Livenes Something good eventually happens. A liveness failure occurs when an activity gets ino a state such that it is permanently unable to make forwardprogress. Deadlock, starvation and livelocks are examples.

wettstein:configuration

2009-08-24T23:12:04+02:00

Methods Common to all Objects

2010-06-29T23:24:22+02:00

Item 8: Obey the general contract when overriding equals Entity-Typen überschreiben selten die equals()-Methode. Da sie keine Werte darstellen, ist der Vergleich des Inhalts praktisch bedeutungslos und aus diesem Grunde ist es völlig in Ordnung, wenn zwei Entity-Objekte genau dann “gleich” sind, wenn sie identisch sind.

Groovy

2011-01-10T10:38:00+02:00

* Fewer imports necessary * Groovy Truth -> if(0) println(“pass”), if(””) println (“Not pass”), if(object) println (“Pass if object !=null) * Public is the default scope, there are only three ones (public, protected, private) * Checked exceptions don't have to be caught * ?. -> access the method only if the object is not null, example person?.name * ?: -> Elvis-Operator: String name = name.getName() ?: “Unknown” -> shortcut for String name = (person.getName() != null) ? person.getName() : …

Editor

2010-11-29T21:51:50+02:00

Editor Ctrl + Alt + T => Switch between Class and TestclassCtrl + Alt + I => Inform about variable, class etc. Ctrl + Alt + v => Add a variable (example new Person() -> def person = new Person())Ctrl + Alt + g => Command lineAlt + Shift + t => Create a new taskCtrl + Shift + Info => Show infos (example: show the image)

Collections

2010-07-01T12:36:03+02:00

Bag (org.apache.commons) -> Defines a collection that counts the number of times an object appears inthe collection. Buffer (org.apache.commons) -> Defines a collection that allows objects to be removed in some well-defined order. (FIFO, LRU cache)

Network

2009-11-03T23:11:55+02:00

find Remove all Subversion-Content find . -name .svn -exec rm -rf {} \; Replace the String bst with fwe in all files of the name Root (recursively) find . -name Root | xargs perl -pi -e 's/bst/fwe/'; Delete old access log files find /tomcat/logs/ -name "*access*" -mtime +40 -exec rm {} \;

Monitoring

2009-03-24T10:06:19+02:00

Check via crontab if a certain webserver is responding: wget -o output.txt --no-check-certificate https://urlofwebserver/test if grep -q "404\|503" "output.txt" ; then echo `date` "M-System not avaiable" >> status.log else echo `date` "M-System ok" >> status.log fi

Tasks

2009-07-27T11:14:36+02:00

Execute a class mvn exec:java -Dexec.mainClass="org.hibernate.tutorial.EventManager" -Dexec.args="list"

Options

2009-07-28T14:39:30+02:00

Options Display result vertically select * from table \G;

Javascript

2009-04-03T09:24:18+02:00

Some theorie Shorthand Character Classes Sign Description \w [a-Z] and [0-9] and _ \s All kind of whitespaces \n, \r, \t Carriage Return, Tab, Line Break \d Decimals \p{} All kind of signs with property X \W ~\w \S ~\s \D ~\D \P{} ~\p{} . Everything except \n ^

Playground

2009-04-03T15:59:13+02:00

URL-Encoding Allowed vocabulary: [a-Z][0-9]~!@#$*()=:/,.;?. Javascript encodeURI to encode the whole url.Example: encodeURI(' l') -> encodeURIComponent to encode a part of the url. Use this if you think for instance that the valueof parameter could contain a '&' Example: encodeURIComponent(' l') -> http%3A%2F%2Fwww.google.ch%3Fhi%3Dhaal%20Link about encoding in javascrip…

Sources

2009-03-20T22:28:44+02:00

Install external repositories Add a line at /etc/apt/sources.lst, for example deb http://deb.opera.com/opera/ stable non-free Add the key from the external repo and declare it for aptitude

Tasks

2009-12-31T13:31:02+02:00

Create a crypted file Vim -x Create shortcuts :ab shortcut text Options :set all Insert Text on multiple lines :x,y s/^/# / x = startline, y = endline Examples c3nichts[ESC]: Ersetzt die folgenden drei Wörter durch nichts d3): Löscht ab der aktuellen Zeile drei Sätze dd: Löscht ganze Zeile fx: positioniert auf das Zeichen x (; wiederholt das Kommando, , wiederholt es jedoch rückwärts) Fx: positioniert auf das Zeichen x, jedoch rückwärts H: Zum Anfang …

Programming

2011-10-17T14:12:25+02:00

Groovy & Grails Java Intellij Shortcuts Maven MySQL Commands Scripts Ubuntu Regular Expressions Vim Security Configuration Work Effective Java Concurrency in Practice

wettstein:work

2010-06-07T15:37:19+02:00