learn jsp and servlets

example The life cycle of a simple tag processorCustomize a simple tag with attributes (like C:foreach? ）Stop page Processing--skippageexceptionStop page processing, not just throwing exceptions, but expecting the first part of the page to be processed as a response, but not the latter part of the process for some reason.The page information after the visible tag (back in the page ...) has no output!What happens if a tag is called from a contained page?Skippageexception just stops calling

). 　　 　　 What are the implied objects (Implicity object) in the JSP page? What are their respective types and functions? 　　 Request-- Reponse-- Session-- Application-- Out-- Page-- PageContext-- Exception-valid only if the current JSP page is the error page. Config-- 　　 　　 What is the difference between the 　　 　　 　　 servlets/

Brief introductionThere are two main techniques for developing Web applications in Java, namely Servlets and JSPs. A servlet is a Java program executed on the server side, and a program called a servlet container (which is actually a server) is responsible for executing Java programs. The JSP (Java Server page) is a page that is executed by the JSP container .Dif

client. Resp),doPost (httpservletrequest req, HttpServletResponse resp) such as The servlet responds to the customer by responding to the object, and the container returns the response to the customer. The service () thread ends, retains or cleans up the responding object, and the customer gets a response. 3. Mark Tomcat Official document Servlet API documentation4, HttpServlet inheritance tree, interface Java.lang.Object Javax.servlet.GenericServletJavax.servlet.http

custom tag, then now a little bit to see how the tag's support code is written. The Java class that completes the tagging work Foo.AdvisorTagHandler.javaThis simple markup processor extends the Simpletagsupport and implements two key methods: Dotag () and Setuser ().Dotag () is the way to do the work, and SetUser () is the method that accepts the value of the property. Details are as follows: El function vs Tag processor Are all Java classes Need to be pla

; Servlet-class>Com.example.ListenerTesterServlet-class> servlet> servlet-mapping> Servlet-name>ListenertesterServlet-name> Url-pattern>/listenertester.doUrl-pattern> servlet-mapping> Web-app> packagecom.example;Importjavax.servlet.ServletContext;Importjavax.servlet.ServletContextEvent;Importjavax.servlet.ServletContextListener; public class Myservletcontextlistener ImplementsServletcontextlistener {@Override public voidcontextinitialized (servletcontextevent serv

("); org.apache.jasper.runtime.JspRuntimeLibrary.include (Request, response, "footer.jsp", out, false ); Out.write ( "\ n"); Out.write ("\ n"); Out.write ("The bold distinction is the conversion code for the include directive and the include action.Param actionModify the index.jsp code above:Modify Footer.jspEffectFoward ActionGarbled problem is not resolved, can only input Chinese. (Request.getparameter ("UserName")null) {% > page= "handleit.jsp"/> %}% > handl

;Importjavax.servlet.*;Importjava.io.IOException; Public classFilterImplementsjavax.servlet.filter{Private intvisited; @Override Public voidInit (Filterconfig filterconfig)throwsservletexception {} @Override Public voidDoFilter (ServletRequest servletrequest, Servletresponse servletresponse, Filterchain filterchain)throwsIOException, servletexception {servletresponse.setcontenttype ("Text/html"); Servletresponse.setcharacterencoding ("Utf-8"); Visited++; Filterchain.dofilter (ServletReque

Servlet and JSP Technology is the Java Development Server-side application of the main technology, is the development of business applications, the standard of the presentation end. Java developers like to use it for a variety of reasons, one is familiar with the Java language developers are easy to learn the technology, the second is the "write, run everywhere" concept into the Web application, the impleme

Java ServletTechnology andJSP TechnologyWith the Java server technology, they currently control the entire server-side Java technology market and gradually become the standard for building commercial Web applications. Java developers like these technologies for many reasons, including: these technologies are easy to learn, one-time writing, and run everywhere (write once, run anywhere ). More importantly, if the following practices are adopted more ef

Let other components take over all requests; Partial takeover requestSome questions--The Intercept point is useful.1. Let other components take over all requests. PackageCom.example.web;ImportCom.example.model.BeerExpert;Importjavax.servlet.*;Importjavax.servlet.http.*;ImportJava.io.*;ImportJava.util.*; Public classBeerselectextendsHttpServlet {@Overrideprotected voidDoPost (httpservletrequest req, HttpServletResponse resp)throwsservletexception, IOException {String C= Req.getparameter ("Color")

First of all, spit groove yourself, old remember the wrong spelling of the word servlets ~ ~ ~At head first Servlets jsp, I felt the fascination of head first (multi-image, one-page-less, this is head).What did the 1.WEB server do for you?Web browser----(the user's request contains the name and address URL of the resource the user is looking for)---> RequestServe

Declaring a generic error pageThis applies to all resources in the Web app, not just the JSP A more explicit exception error declaration Declaring error page based on HTTP status code Configuring servlet initialization in DDThe servlet is initialized by default when the first request arrives, and you can set the Load-on-startup element if you want to load the servlet when the deployment or server restarts.If multiple elements ar

is not serializable? For migration, the Property object class needs to be httpsessionactivationlistener and the activation/deactivation callback method is used to solve the problem. Listener Example Session counterThis listener allows you to track the number of active sessions in this web app:To configure listeners in DD:Attention: Attribute Supervisor ListenerThis listener can be traced every time a property is added to a session, a property is deleted, or a property is repla

type first, and then change to another type to continue writing.6. Why should I return a file through a servlet instead of returning it directly? The reason is that you want to perform some logic before and after returning a specific type of file, such as determining whether the user has permission to download the file.7, some things to remember, about the output, there are only two choices: characters or bytes.Output streams that can be returned via resp ... /* Omit parameter */ // can

Cookie ("userid", UserID); Resp.addcookie (cookie);Once the cookie is sent from the server side to the client, there is no way for the server side to display the cookie deletion. However, a substantial deletion of the client cookie can be achieved by overwriting the expired cookie.New Cookie ("userid", UserID), Cookie.setmaxage (0); Resp.addcookie (cookie) ;Chinese charactersIf the contents of a cookie are Chinese characters, you need to encode it:String username = java.net.URLEncoder.encode ("

shown below (click to view larger image):Click on the network, you can observe a header named Loction, the content is exactly the URL we redirect, then if the servlet code is changed to "Resp.setheader (" Location "," http://www.cnblogs.com/xkxf/"); Can I implement redirection? The answer is no, but add the words "resp.setstatus (302);" It is possible to achieve this effect.7. Finally, what does Sendredirect ("another URL") mean? The explanation in the book is that you want the browser to proce

;/cookietest.doUrl-pattern> servlet-mapping> servlet> Servlet-name>CheckcookieServlet-name> Servlet-class>Com.example.web.CheckCookieServlet-class> servlet> servlet-mapping> Servlet-name>CheckcookieServlet-name> Url-pattern>/checkcookie.doUrl-pattern> servlet-mapping>Web-app> PackageCom.example.web;Importjavax.servlet.ServletException;Importjavax.servlet.http.*;Importjava.io.IOException;ImportJava.io.PrintWriter; Public classCheckcookieextendsHttpSe

-class>Com.example.web.JarDownloadServlet-class> servlet> servlet-mapping> Servlet-name>TestServlet-name> Url-pattern>/jardownload.doUrl-pattern> servlet-mapping>Web-app>4. Prepare a test jar package and place it in D:\APACHE-TOMCAT-7.0.77\WEBAPPS\JARDOWNLOAD-V15. Write a servlet with full name com.example.web.JarDownload, compile it into a. class file and deploy to D:\apache-tomcat-7.0.77\webapps\JarDownload-v1\ Web-inf\classes\com\example\web PackageCom.example.web;Impor

How can a successful Jsp programmer learn JSP? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. A common error is to treat JSP as a simplified Java. It is not. (In fact, JSP is a simplified