Tuesday, 30 July 2013

Java performance mind map

Great https://github.com/raydac/Java-performance-mind-map
or https://www.dropbox.com/s/zvg9vmjn1dqd21f/JavaPerformanceOptimization.png

includes following topics and ways how to diagnose and fix them:
  • too big %sys in mpstat
  • too big %irq, %soft in mpstat
  • too big %iowait in mpstat
  • too big %idle in mpstat
  • too big %ust in mpstat - JVM, algorithmic , memory, cpu problems

Friday, 5 July 2013

Horizontal scrollbars at top & bottom in Datatables

In my data table I have a lot of data so horizontal scroll is required. I found library jQuery-doubleScroll but it doesn't work with DatTables. Reason is that DatTables adds some parent divs to the original table. Solution is to wrap table with own div and use it for double scroll. Here is short example:

Tuesday, 25 June 2013

Google Charts tutorial

This short tutorial describes how to create chart using Google charts api

Monday, 3 June 2013

Resolve wrong plugin installation in the Eclipse

Eclipse gives error when I'm trying to open any .properties file -  
"An error has occurred. See error log for more details. 

This solution could resolve any wrong plugin installations errors, you could 
revert to your old configuration:
1.  Help -> About Eclipse
2.  Installation Details
3.  Installation History (tab)
4.  Select the last "good" configuration
5.  Press Revert

Tuesday, 30 April 2013

Ajax file uploading SyntaxError in ExtJs

After submitting the form with file it gives me SyntaxError <pre> </pre>in firefox , cause of this error was content type, it was application/json, to fix problem yous should change it to application/xml ( in java response.setContentType("application/xml"))

Tuesday, 23 April 2013

Speed up the gwt compiler

1) Add argument to the gwt compiler:

2) In your *.gwt.xml specify browser, ex:
  <set-property name="user.agent" value="gecko1_8"></set-property>

Tuesday, 26 March 2013

Spring TaskExecutor and JavaMailSender

Spring has implementation for concurrency tasks based on java concurrency. Next I will create mail sending service (JavaMailSender - is extenden from JavaMail interface MailSender ) using task executor

Wednesday, 9 January 2013

Spring scheduled annotation

 Spring has nice feature called scheduler. Just simply create class and annotate method with @Scheduled(...) annotation and it's all. You have scheduled task, that wil be executed based on your time expression. Example: