Doubt of Developers

WHAT IS SERVLET? Servlet technology is used to create web application resides at server side and generate web pages. Servlet technology is robust and scalable because of java language.Before servlet ,CGI(common gateway interface) scripting language was popular as a server side programming language.But there was many disadvantages of this technology. There are many interfaces and classes in the servlet API such as servlet,GenericServlet,HttpServlet,ServletRequest,ServletResponse etc. Servlet is a class that extend the capabilities of the servers and respond to any type of request. Servlet is a web component that is deployed on the servers to create dynamic web page. HOW WEB SERVERS WORKS?   To retrieve a static page , a user enters a url in to a browser. Browser generates an HTTP request to appropriate server.   Web server maps the request to the particular file and that file is returned to the browser in an HTTP response. HTTP header in resp...

JAVA DATABASE CONNECTIVITY Ø   JDBC-: Java database connectivity (jdbc) is an application programming interface which allow the programmer to connect and interact with databases. Ø   It provides methods to query and update data in the database through update statement like SQL create,update and insert and query statement such as select. Ø   Like java ,jdbc is compatible with many platforms like UNIX and MAC OS. Ø   JDBC API uses jdbc drivers to connect with the database. WHY USE JDBC? Before JDBC,ODBC API was the database API to connect and execute query with the database .But ,ODBC API uses ODBC driver which is written in C language (i.e. platform dependent and unsecured ).That is why java has defined its own API that uses JDBC drivers. WHAT IS API? API(Application programming interface )is a document that contains description of all the features of a product or software.It represents classes and interfaces that software programs ca...