MySQL SQLSTATE[HY000] [1524] Plugin is not loaded

Hello,
Sometimes when working with PDOConnections to Mysql this errors is thrown,

..... In PDOConnection.php line XXXX:
  SQLSTATE[HY000] [1524] Plugin '*9CBB2AF8EB953A91706ADC84736447DE04E311E9' is not loaded
Note that, connection to database through command line or phpmyadmin web interface is possible and don"t raise exceptions

This error is probably due to password ecnryption method in Mysql
Follow these few steps
Connect to mysql using root:

>mysql -u root -p
-----Provide your password-----
>use mysql;
>update user set authentication_string=PASSWORD("USER_PASSWORD") where User='YOUR_USER';
>update user set plugin="mysql_native_password" where User='YOUR_USER';  # THIS LINE
>flush privileges;
>quit;

Tuto Spring Boot Webservice / JPA Repository / Oracle / Maven / Eclipse

This tutorial aims to build a simple web service using spring boot .
Let's start by ddownload our start package from :
https://start.spring.io/

We will call our project solvability <=> Artifact a sub functionnality of an extranet web services portal tn.cnss.extranet.employeur <=>Group
We will also choose maven to manage dependencies, tests and continuous dev/deployement actions

fig 1- Starting springboot package

Now w will import our project in eclipse environnement :
File > Import maven project

fig 2- Import project in eclipse

fig3- Before maven configuration

Once the project was imported, we will configure maven configuration in eclipse by indicating our M2_HOME
by default maven is configured to store dependencies on /user_home/.m2/repository as shown in this image


And after modification:

fig4- After maven changes

Now we will add our unique additional dependency (oracle driver)
Here ive already in my repo oracle 11.2.0.4 driver
For those who don't have oracle driver installed :
 1- Start by downloading the ojdbc (or copy it from sqldeveloper tool if you use it)
2- run this command :
mvn install:install-file -Dfile=<path-to-oracle-driver-file>

Once all is done we add the dependency tag in our pom file

        <dependency>

            <groupId>com.oracle</groupId>

            <artifactId>ojdbc</artifactId>

            <version>11.2.0.4</version>

        </dependency>

fig5- Oracle dependency

fig6- application.properties file

Now let's continue:
We have to setup our /src/main/resources/application.properties file; and put some needed parmaters:
in our case:
spring.datasource.url=jdbc\:oracle\:thin\:@ip.ip.ip.ip:\port\:SID
spring.datasource.username=user_name
spring.datasource.password=user_password
spring.jpa.properties.hibernate.show_sql=true_or_false
spring.jpa.properties.hibernate.use_sql_comments=true_or_false
spring.jpa.properties.hibernate.format_sql=true_or_false
server.port = our_webservice_port_number
logging.level.org.hibernate=ERROR_see_hibernate_logging_level
NB: ERROR is less verbose



Note now our application can start without errors.

Let's continue
Now we will create our RestController (Entry points for remote invokations)
A RestController is a java class annotated with @RestController
(Reference to org.springframework.web.bind.annotation.RestController)

To make our code structured we can create a package controller under our project

fig7- controllers package

And then we create our controller  under the new created  package
In our case we will check the solvability of a customer we will need two params
root number and key (consistency)
we will invoke that method from "APP_URL/check-solvability " with simple http GET request

So we use
@GetMapping annotation

So the behavior of our code  could be

 /**
  * Check if customer is solvable or no
  * @param root
  * @param key
  * @return true or no
  */
 @GetMapping( "/check-solvability/{rootValue}/{keyValue}") 
 public String getCustomerFinancialSituation(@PathVariable String rootValue, @PathVariable String keyValue ){
  //Some logic here 
  //For exemple if we will return true always
   JSONObject output = new JSONObject();
   output.put("result", "ok");
   output.put("value","1");
   return output.toString();
 
 }

Let's instroduce a business layer (it's logic that the business rules are delegated to a seperated class  
And we create our business layer or business package 

and business implementations package



fig8- business package

And we create this interface that will be implemented by the financial dev team 

fig9- business interface

Let's continue
Once interface is created we can proceed to business injection in the main controller, this can be done by these two lines

 @Autowired
 private FinancialBusiness financialBusiness;

fig10- business injection

Lets's continue

Now we create implementation package for business, and a specific implementation for our previously ceated interface Financial business

fig11- business interface implementation

if you want to interoduce repositories cantact me for more advanced example.

Remmina login failed for display 0 Centos client / xrdp server on Centos 7

Hello,
When trying to connect my desktop pc (CentOS 7 ) to my new Laptop (CentOS 7) vusing Remmina, i've faced this problem :
Login successfull and then a message window saying:
sending login info to session manager, please wait
login failed for display 0

is shown.

I tried  to change xrdp.ini file by modifying some parameters such as max_sessions or bpp values but the error persists to update my remmina version or to changs session manager params .....

When i used windows mstsc i discovered that is works fine, rdesktop works fins also(but loud)  I was certain that the problem was remmina's one ...


Solution was very simple for Remmina after 2 days   😕😕😕😕😕
i've just changed
color depth combobox value in my case to 24bpp (max_bpp=32 in /etc/xrdp/xrdp.ini) 

Now it works fine and with correct desktop refresh speed

 

JPA : Hibernate implementation raises exception when retrieving jdbc connection

For some cases, there a need to retrieve jdbc connection to execute some database operations such as batch works; tables loading from big files or others .....

When working with enitity manager

Connection conn = em.unwrap(Session.class).connection();  

raises an exception when working with an hibernate implementation (works fine with eclipselink)

One solution is :

public Connection hibernateConnection() {
  SessionImplementor si = (SessionImplementor) entityManager.unwrap(Session.class);
  try {
   return si.getJdbcConnectionAccess().obtainConnection();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
   return null;
  }
  
  
 }

JBoss 7 - JSF null value input become 0

this problem occures when binding an input in jsf to a numeric attribute in the bean.
Usually when we are running the app on apache tomcat we addthis jvm paramter in the tomcat VM
-Dorg.apache.el.parser.COERCE_TO_ZERO=false

For those who are running on JBoss Server 7.x
adding a context parameter

<context-param>
    <param-name>javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL</param-name>
    <param-value>true</param-value>
</context-param> 

in standalone.xml file did not work for me.
One working solution is to create is to add a listener to your web app that adds this parameter dynamically
Here is the code
'Here i'm using WebListener annotation'

  
package com.cnss.ds.web.utils;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;


@WebListener
public class AppWebLsistener  implements ServletContextListener {
 @Override
    public void contextInitialized(ServletContextEvent event) {

        System.setProperty("org.apache.el.parser.COERCE_TO_ZERO", "false");
    }

 @Override
 public void contextDestroyed(ServletContextEvent arg0) {
  // TODO Auto-generated method stub
  
 }

}

graphicupload :CKEditor plugin for image upload

Default CKEditor plugins allows files upload through a complicated and non intuitive dialog box.

graphic upload is a sample plugin which allow images upload  and insertion in CKEditor
Here is some printscreens

the plugin is available at

https://github.com/wassimjied/graphicupload