GURFL data

GURFL file is a list of operators and their associated IP address ranges. This is a good way to find out from which mobile carrier (ie. which country) does a request come from.

Earlier it was available at: 

But now days it is down. So I am attaching the last GURFL updated operators.csv file here

Log4j errors : log4j:WARN No appenders could be found for logger, log4j:WARN Please initialize the log4j system properly

This is a very common problem, it occurs when not found in classpath.

Create a file called Place it in the root folder where your java classes are found. When log4j initializes, it will look for a file named EXACTLY (if you are using a properties file).

Another alternate way is to put the path to the file in your classpath.

Hope this will help you 🙂 

org.h2.jdbc.JdbcSQLException: The object is already closed [90007-113]

While running junit using in memory database H2 I was hitting this error. I was testing my spring DAO classes that are using JDBCTemplate. In a single Junit testing, to test various scenario  I was calling a single DAO method with different parameters . It start giving the error "The object is already closed" as it finishes testing the DAO method with first parameter.

Then I investigated in JDBCTemplate and found that it closes connection after every execution of query using Finally statement.

finally {
            DataSourceUtils.releaseConnection(con, getDataSource());

To solve this issue I override the JDBCTemplate and created my own JDBCTemplate in which I have removed the Finally statement.