I know that I know nothing

datasource Initializer for run sql script

clock July 21, 2016 23:40 by author Administrator

some time our application have initial data or sometimes needs to run sql script to create tables or other database object when application init.


in this code when can do that very simple and easy by spring boot 



private DataSource dataSource;



 private Resource schemaScript;


public DataSourceInitializer dataSourceInitializer(final DataSource dataSource) {

         final DataSourceInitializer initializer = new DataSourceInitializer();





private DatabasePopulator databasePopulator() {

        final ResourceDatabasePopulator populator = new ResourceDatabasePopulator();




localStorage JSON

clock June 10, 2016 19:21 by author Administrator

when set and get  json in localStorage will add this type 


var authToken = JSON.parse(localStorage.getItem("authenticationToken"));


localStorage.setItem("authenticationToken",JSON.stringify( token));

request oauth token by jquery ajax

clock June 10, 2016 15:08 by author Administrator
            var atoken;
			  url: "<c:url value = '/api/oauth/token' />",
			  type: 'POST',
			  crossDomain: true,
		      async: false,
		      cache: false,
			  data: {
			  success: function(token, status) {
				  //store.set('token', token);
			  beforeSend: function (xhr) {
				 xhr.setRequestHeader ("Authorization", "Basic " + btoa("acme:acmesecret" ));


spring security oauth2 change default prefix path

clock June 8, 2016 23:40 by author Administrator

when add oauth to your project 

oauth library create some endpoint for get token .get authorize code ,get refresh token and some other oauth protocol

this endpoint has rest url s in this url


Mapped "{[/oauth/authorize]}


Mapped "{[/oauth/token],methods=[GET]}"


Mapped "{[/oauth/check_token]}"



when your project run in root servlet-path every thing is ok .but when using servlet-path:/api or other name 

request to /api/oauth/token for get token is get exception

for solve this problem need to change default configuration for oauth path for change it nee write this configuration code


public void configure(AuthorizationServerEndpointsConfigurer endpoints) throws Exception {




handle nvl in postgres

clock June 5, 2016 19:51 by author Administrator
CREATE OR REPLACE FUNCTION nvl(expr1 text, expr2 text)
  SELECT coalesce($1, $2);

testing tools

clock March 11, 2016 21:19 by author Administrator

Hibernate 5 : generator class=“sequence” not working

clock March 3, 2016 18:54 by author Administrator

after upgrade hibernate 4 to 5 sequence not working and hibernate get next val from hibernate_sequence  but 

I solved it by re-configuring mapping in the HBM file from:

<generator class="sequence">

           <param name="sequence">PRODUCT_ID_SEQ</param>



<generator class="">

          <param name="prefer_sequence_per_entity">true</param>

          <param name="optimizer">none</param>

          <param name="increment_size">1</param>

          <param name="sequence_name">PRODUCT_ID_SEQ</param>



Oracle Table Flash Back Query

clock March 2, 2016 21:31 by author Administrator

From Oracle Ver. 9i Oracle has introduced Flashback Query feature.  It is useful to recover from accidental statement failures. For example, suppose a user accidently deletes rows from a table and commits it also then, using flash back query he can get back the rows.

Flashback feature depends upon on how much undo retention time you have specified. If you have set the UNDO_RETENTION parameter to 2 hours then, Oracle will not overwrite the data in undo tablespace even after committing until 2 Hours have passed. Users can recover from their mistakes made since last 2 hours only.

For example, suppose John gives a delete statement at 10 AM and commits it. After 1 hour he realizes that delete statement is mistakenly performed. Now he can give a flashback  AS.. OF query to get back the deleted rows like this.

Flashback Query

SQL>select * from emp as of timestamp sysdate-1/24;


      TO_TIMESTAMP('2007-06-07 10:00:00', 'YYYY-MM-DD HH:MI:SS')








What is difference between Abstract classes and interface in JAVA 8?

clock February 27, 2016 20:57 by author Administrator
  • Interesting to know that now with Java 8 is possible to use a method body of an interface.So in Java 8, the only difference between an interface or an abstract class depends if we want all the methods to be public or not? (Or to implement multiple interfaces in a class like said by Piotr )
  • ,jQuery15206033902112394571_1456594024402??

proxy(forward proxy) vs reverse proxy

clock November 5, 2015 18:31 by author Administrator

A reverse proxy is mostly a server-side concept, and is usually used in the context of CDNs (content distribution networks) for caching static HTTP content. A forward proxy is usually a client side concept used for anonymity, to subvert censorship, and (back in the days of dial-up) as a web accelerator.

About the author

 Welcome to this web site . This page has two purposes: Sharing information about my professional life such as articles, presentations, etc.
This website is also a place where I would like to share content I enjoy with the rest of the world. Feel free to take a look around, read my blog

Java,J2EE,Spring Framework,JQuery,

Hibernate,NoSql,Cloud,SOA,Rest WebService and Web Stack tech...


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