It is so common need to dig some info in Linux remote machines where you have just a terminal access. Effectiveness of searching might be crucial in finding necessary files and content. Here are couple of commands come to help as: grep – search in file contents find – search by file name It happens that sometimes quite difficult to…
How to run Linux command in background? How to keep it running after leaving terminal session?
When working with remote server through terminal it is common to run some processes in background. For example to start zipping something, put it into background and keep working on something else. Or even start a process and leave it running when you quit a terminal session. A quite common example could be – start application server. You just need…
What is a functional interface in Java8? Quick explanation and sample.
Any interface with a single abstract method is a functional interface and its implementation may be treated as lambda expression. It can have only a single functionality. However a functional interface can have unlimited default methods. Note, that default methods have implementation and abstract methods – not. The latter can be only one in functional interface. When defining your own…
What is a method reference in Java8? Quick explanation and samples.
Method reference – Lambda expression, which calls known method, written in shorter, more compact way. This is how we can define it in a short way. There are 4 types of method references: Reference to a static method Reference to an instance method of a particular object Reference to an instance method of an arbitrary object of a particular type…
What is Lambda expression in Java8? Quick explanation and Sample.
Lamba expression – an anonymous function that can be passed to or returned from a method. The most simple case of a lambda is a functional interface with a single method which receives some values and return a value. Actually any interface with a single abstract method can be treated as functional interface. Its implementation is called Lambda expression. So it is…
Could not find saved view state for token j0ej17tvl… What can be the cause?
Problem When observing Weblogic server log files, there are occasional occurancies of Error message: Could not find saved view state for token XXXXXXXXX… Where XXXXXXXXX is randomly generated string for each page post request. This error always comes along with: ADF_FACES-30107:The view state of the page has expired. Reload the page. Some background info Each web page, which posts a request…
A quick Regular expressions (Regex) manual / cheat sheet. Samples.
Obviously regular expressions is a little, but powerful helper to implement various complex requirements. As it is a text search oriented functionality, it is extremely useful in DB based tasks related to data ETL layers, searching and other open text related logic. But it is used entirely everywhere. Almost every text editor support regex search file contents. Its very beneficial…
How to tune JDeveloper memory settings to get better performance?
Thats natural that JDeveloper out of the box comes with minimal settings for resource usage. And obviously it is far away not enough for comfortable usage. So there are at least couple of settings that needs to be tuned right after installation: Java heap size Open file %MW_HOME%/jdeveloper/ide/bin/ide.conf and add/change following two lines Java MaxPermSize Open file %MW_HOME%/jdeveloper/jdev/bin/jdev.conf and add/change following…
After macOS High Sierra system update JDeveloper does not start. How to fix it?
It happens, that each time when I push MacOS High Sierra regular updates, my JDeveloper does not start any more. The fix looks very simple, just need to delete JDeveloper system directory. Sounds frightening, but do not be confused because of naming. By fact it is just operational directory where JDeveloper keeps various temporary and configurational stuff. It is even…
How to keep custom JDeveloper preferences after deleting its system folder?
Time to time it happens, that JDeveloper stops working for some reason. It just not open or behaviour become unstable. The fastest and easiest fix is to delete its system folder. Which is like a temporary one, created on the very first run of JDeveloper. There it keeps various cache information and settings. Among those settings there are user preferences…