java - Pass data in JSP from Servlets: Trick -

java - Pass data in JSP from Servlets: Trick -

i'm work jsp,jstl,servlet etc. @ present.i have problem.i don't understand case.

case 1 (this case first-class work,shows database records in jsp file): servlet @webservlet("/books") public class indexcontroller extends httpservlet { private static final long serialversionuid = 1l; protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request, response); } protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { arraylist<book> books = new bookdao().getallbooks(); request.setattribute("books", books); request.getrequestdispatcher("index.jsp").forward(request, response); }

jsp

<c:foreach items="${books}" var="book"> ${book} </c:foreach> case 2 (this case doesn't work,don't show database records in jsp file): servlet @webservlet("/") public class indexcontroller extends httpservlet { private static final long serialversionuid = 1l; protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request, response); } protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { arraylist<book> books = new bookdao().getallbooks(); request.setattribute("books", books); request.getrequestdispatcher("index.jsp").forward(request, response); }

jsp file same above.

case 1: seek localhost/appname/books => works.

case 2: seek localhost/appname/ => doesn't work

i want localhost/appname page show me database records.what ?

java jsp servlets jstl