Hi all, I have few doubts to be clarified in designing our Web framework. I will appreciate, if you can provide me the guidance in the following issues regarding Singleton. 1. How to use Singletons ? : I have few Singleton classes like DBConnectionPoolManager. I would like to know, what is the right way of using this class. For example, just before we need a Connection object, can we call ConnectionPoolManager.getInstance() and then call the getConnection() method ? That means for every servlet which accesses the database, there will be a new instance of this Singleton ? But is it not that we need to have one instance for the whole of application irrespective of pages ? Where and when do we need to instantiate this DBConnectionPoolManager class ? It has to be at the application start-up time, right ? But how ? 2. I have a ConfigurationManager, which basically will get all the setting properties from a single .properties file. For example, for DBConnectionManager, it gets the properties of driver, URL, user-id and password; for mailing services, it gets the properties like SMTP host, port, etc., I want to know whether this ConfigurationManager has to be a singleton ? Since there is only one .properties file for all the configuration properties like database, mail, etc., whether it is required that ConfigurationManager has to be a Singleton ? I will get all the properties at initialization time and load the properties as an in-memory object. That way, it is not required to be a Singleton, right ? 3. I also have a LogWriter Class. Again all my logging should go to only one log file (basically a .txt file) based on the debug level with timestamp. So from any part of the application, say any JSP, I need to call LogWriter class for writeLog(String str) method. Should I design this a Singleton ? If not, how do I ensure that many instances of this class doesn't create many instances of the log file ? Thank you, Raj =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". Some relevant FAQs on JSP/Servlets can be found at: http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.html http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
