I was checking the actual Elasticsearch Java Api and while I created a NodeClient with the api I got lots of exceptions which is frustrating because I just did a clean install and there's nothing complicated in my pom.xml.
These are exceptions I got with the following of a huge stacktrace of course.

java.lang.ClassNotFoundException: groovy.lang.GroovyClassLoader
 at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_66]

java.lang.ClassNotFoundException: com.github.mustachejava.Mustache
 at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_66]
 

java.lang.ClassNotFoundException: org.apache.lucene.expressions.Expression
 at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_66]
 

java.lang.ClassNotFoundException: com.sun.jna.Native
 at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_66]

So I made maven generate a dependency tree, checked dependencies in elasticsearch client parent pom and added the necessary dependencies one by one by hand. Note that these are for Elasticsearch 2.1.1. For the version of your dependencies you should check org.elasticsearch.elasticsearch pom of your version of Elasticsearch.

  
 
            org.codehaus.groovy
            groovy-all
            2.4.4
        

        
            com.github.spullara.mustache.java
            compiler
            0.8.13
        

        
            org.apache.lucene
            lucene-expressions
            5.3.1
        

        
            net.java.dev.jna
            jna
            4.1.0
        

exception after main class package change in spring boot

In my Spring Boot toy project ( web + mongodb), I want to change the structure of my packages. My old structure was like this:

Putting @ComponentScan annotation (without a base package) was fine for scanning all my classes. But when I update the structure and moved my main file (BootQeyfi) to launch package, I needed to update base package with
@ComponentScan(basePackages = "main") . After that definition Spring will scan the main as a base package and handle everything perfectly.

But of course that's not the case. I got the following exception which basically means "I could not autowire your repository class (your interface which extends MongoRepository)" 

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private main.service.HelloService main.controller.HelloController.service; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: main.dao.ProductRepository main.service.HelloService.repository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [main.dao.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
 at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
 at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
 at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
 at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:703)
 at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
 at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
 at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:120)
 at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:648)
 at org.springframework.boot.SpringApplication.run(SpringApplication.java:311)
 at launch.BootQeyfi.main(BootQeyfi.java:27)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private main.service.HelloService main.controller.HelloController.service; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: main.dao.ProductRepository main.service.HelloService.repository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [main.dao.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
 at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
 ... 14 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: main.dao.ProductRepository main.service.HelloService.repository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [main.dao.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
 at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
 at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
 at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
 at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1017)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
 ... 16 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: main.dao.ProductRepository main.service.HelloService.repository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [main.dao.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
 at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
 ... 27 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [main.dao.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1103)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:963)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
 ... 29 more

To fix this problem, @EnableMongoRepositories must be added to your main class. My repository is under "main.dao" so my definition is like @EnableMongoRepositories(basePackages = "main.dao").

fixing "no such app as" error in heroku deployment after application rename

I did few changes in my toy project and pushed it to heroku with

git push heroku master

but got this error:

!  No such app as myOldApplicationName.

fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I googled a bit to see that this is due to my application rename in heroku website. The previous name was "myOldApplicationName". Then I searched my .git directory to see if there are references to the old application name. I found it under "config".

[remote "heroku"]
 url = git@heroku.myOldApplicationName.git

Edit it with your new application to fix the issue.

[remote "heroku"]
 url = git@heroku.com:myNewApplicationName.git

fix for the performance problem of mysql memory tables

In our project, a very high database performance is needed. Thus we create our critical tables as memory engine tables but although our queries are using corresponding indices we still can't achieve the needed performance. After few research in google I see that tables of memory type are having "hash" indices by default. After we drop the "hash" indices and replace them with "b-tree" ones, we had a much better performance in our project. So for those of you with performance problems using memory tables, I recommend trying b-tree indices.

problem while using dbcp with oracle database

We have two different databases in a project; an Oracle and a MySql one. Both of them need connection pooling for a better performance. First, I add dbcp context for mysql to my application context. The settings were quite straightforward. But when I try to use the same settings (except for the connection url and the driver class name of course) for the Oracle data source I got the following exception:

org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (ORA-00923: FROM keyword not found where expected

which can be translated as "there's some FROM statement missing somewhere while setting your connection". My validation query for MySql was just "SELECT 1" which annoys Oracle database. I change it to "SELECT 1 FROM DUAL" and it's fixed.

three screens in vlc media player while playing wmv

If you're trying to watch a video of Windows Media Video (WMV) format with vlc player but vlc is opening three windows of the video in the same time let me give you a hand. First open Video - Video Track from the menu and then select disable and then track 1. One window is better than three for a movie, right?

how to fix sudo command in zenwalk 6

What you wait from sudo command is that it gives you the power of root for a single command. But you'll notice that it does not work properly in Zenwalk 6. To fix it;

check your group by opening your start menu > system > control panel > user profiles > list users > your_username > hit ok > note groupname value

open Terminal

type

su

and login (then you become root)

type

mousepad /etc/sudoers

edit the line after

# Uncomment to allow people in group wheel to run all commands

comment as

%your_groupname_value ALL=(ALL) ALL

and save. Voila.

operation aborted error of maxthon 2

I was getting "operation aborted" error from maxthon 2 everytime I hang on facebook.
Here's the cure:

-open maxthon setup center
-choose "add hunter" from the left tab.
-click on "edit filter list" link of "content filter"
-add "facebook" to the white list