Error when calling the Stored procedure in mysql(JAVA hibernate)

I have a strange problem that i can call the MySQL stored procedure successfully. But calling it using Java returns an error.

Following is my Controller method:

public double getBalance(String number) {
    double balance ;
    try {
        Query query = getSession().createSQLQuery("CALL getBalance(:string_number)").addEntity(Wallet.class)
                .setParameter("string_number", number);

        List result = query.list();

        if (result.size() == 0) {
            balance = -1.0;
        } else {
            balance = (double) result.get(0);
        }
    } catch (Exception ex) {
        throw ex;
    }
    return balance;
}

This is my stored procedure:

CREATE DEFINER=`root`@`localhost` PROCEDURE `getBalance`(IN string_number varchar(19))
BEGIN
select amount from wallet where number=string_number;
END

The error is:

SEVERE: Servlet.service() for servlet [dispatcher] in context with path 
[/DigitalWallet] threw exception [Request processing failed; nested 
exception is javax.persistence.PersistenceException: 
org.hibernate.exception.SQLGrammarException: could not execute query] with 
root cause
java.sql.SQLException: Column 'number' not found.

I have the number column and i can call the stored procedure in MySQL Workbench successfully.