java - What is the difference between JSF, Servlet and JSP? -

-

how jsp , servlet related each other? jsp kind of servlet? how jsp , jsf related each other? jsf kind of prebuild ui based jsp asp.net-mvc?

jsp (javaserver pages)

jsp java view technology running on server machine allows write template text in client side languages (like html, css, javascript, ect.). jsp supports taglibs, backed pieces of java code let control page flow or output dynamically. well-known taglib jstl. jsp supports expression language, can used access backend data (via attributes available in page, request, session , application scopes), in combination taglibs.

when jsp requested first time or when web app starts up, servlet container compile class extending httpservlet , use during web app's lifetime. can find generated source code in server's work directory. in example tomcat, it's /work directory. on jsp request, servlet container execute compiled jsp class , send generated output (usually html/css/js) through web server on network client side, in turn displays in web browser.

servlets

servlet java application programming interface (api) running on server machine, intercepts requests made client , generates/sends response. well-known example httpservlet provides methods hook on http requests using popular http methods such get , post. can configure httpservlets listen http url pattern, configurable in web.xml, or more java ee 6, @webservlet annotation.

when servlet first requested or during web app startup, servlet container create instance of , keep in memory during web app's lifetime. same instance reused every incoming request url matches servlet's url pattern. can access request data httpservletrequest , handle response httpservletresponse. both objects available method arguments inside of overridden methods of httpservlet, such doget() , dopost().

jsf (javaserver faces)

jsf component based mvc framework built on top of servlet api , provides components via taglibs can used in jsp or other java based view technology such facelets. facelets more suited jsf jsp. namely provides great templating capabilities such composite components, while jsp offers <jsp:include> templating, you're forced create custom components raw java code (which bit opaque , lot of tedious work in jsf) when want replace repeated group of components single component. since jsf 2.0, jsp has been deprecated view technology in favor of facelets.

as being mvc (model-view-controller) framework, jsf provides facesservlet sole request-response controller. takes standard , tedious http request/response work hands, such gathering user input, validating/converting them, putting them in model objects, invoking actions , rendering response. way end jsp or facelets (xhtml) page view , javabean class model. jsf components used bind view model (such asp.net web control does) , facesservlet uses jsf component tree work.

related questions


Comments

Post a Comment

Popular posts from this blog

c++ - Convert big endian to little endian when reading from a binary file -

-
this question has answer here: how convert between big-endian , little-endian values in c++? 28 answers i've been looking around how convert big-endian little-endians. didn't find solve problem. seem there's many way can conversion. anyway following code works ok in big-endian system. how should write conversion function work on little-endian system well? this homework, since systems @ school running big-endian system. it's got curious , wanted make work on home computer also #include <iostream> #include <fstream> using namespace std; int main() { ifstream file; file.open("file.bin", ios::in | ios::binary); if(!file) cerr << "not able read" << endl; else { cout << "opened" << endl; int i_var; double d_var; while(!file.eof()) {...
Read more

C#: Application without a window or taskbar item (background app) that can still use Console.WriteLine() -

-
i'm trying create application adheres following: no taskbar no console or form window can utilize console.writeline() . (i.e. if executes app command prompt write console.) the problem if create windows form (or wpf) application can have there no taskbar, console or window show up, console.writeline() nothing. if create console app, writes console, can't figure out how hide (and if did hide it, write command prompt window?)... how do this? just create standard console application. callers responsibility hide window caused program (from how run c# console application console hidden ): system.diagnostics.processstartinfo start = new system.diagnostics.processstartinfo(); start.filename = dir + @"\myprocesstostart.exe"; start.windowstyle = system.diagnostics.processwindowstyle.hidden;
Read more

unicode - Are email addresses allowed to contain non-alphanumeric characters? -

-
i'm building website using `django. website have significant users non-english speaking countries. i want know if there technical restrictions on types of characters email address contain. are email addresses allowed contain english alphabets, numbers, "_", "@" , "."? are allowed contain non-english alphabets "é" or "ü"? are allowed contain chinese or japanese or other unicode characters? email address consists of 2 parts local before @ , domain goes after. rules these parts different: for local part can use ascii: latin letters - z - z digits 0 - 9 special characters !#$%&'*+-/=?^_`{|}~ dot ., not first or last, , not in sequence space , "(),:;<>@[] characters allowed restrictions (they allowed inside quoted string, backslash or double-quote must preceded backslash) plus since 2012 can use international characters above u+007f , encoded as utf-8 . domain part more res...
Read more