head first servlets and jsp

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

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

-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

Js|servlet Java servlet Technology and JSP technology enable Java server-side technology, currently they control the entire server-side Java technology market, and gradually become the standard for building commercial Web applications. Java developers like these technologies for a number of reasons, including: These technologies are easy to learn, write once, run everywhere (write Once, run Anywhere). More importantly, if the following practices are

Obviously Tomcat has these packages underneath, but it also needs to add this dependency to Maven dependencies introduction of Servlet start - Dependency> groupId>Javax.servletgroupId> Artifactid>Javax.servlet-apiArtifactid> version>3.1.0version> Dependency> introduction of Servlet end - introduction of JSP related start - Dependency> groupId>javax.servlet.jspgroupId>

multiple Web servers, you can use a free or inexpensive server and have him support servlets, which can significantly reduce costs. Flexibility: Because Servlets is running on the Java platform, Servlets can easily be moved from one platform to another, resulting in a much greater flexibility because of the cross-platform nature of Java. A

In the whole JSP world, they are not a standalone, and there are many server software supporting JSP. They are mainly used in the commercial field, the most important of which is Allaire Jrun, IBM Websphere and BEA Weblogic. Allaire Jrun Allaire's JRun is a Java engine with the widest applicability. It is used to develop and implement server-side Java applications written by Java

Best Practices prepared by Servlets and jsp (the preferred choice for SUN Enterprise Applications). Here we assume that the reader has understood the basic working principles of the two. This article covers the following content: This section briefly introduces Java Servlet and JavaServer Pages (jsp (preferred for SUN Enterprise applications )). Provides tips

then sent to the server and sent to the client by the server. Unlike CGI, the servlet does not generate a new process, but rather is in the same process as the HTTP server. It reduces the cost of the server by using threading technology. The servlet processes the request by invoking the service method when a request is received from the client, in which the servlet first determines what type of request is coming (Get/post/head ...). , and then calls

). 　　 　　 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/

Excerpt from: "Lightweight Java EE Enterprise Application" Third editionFor each client request, the Web server roughly needs to complete the following steps:1. Start a separate thread2. Use I/O stream to read the user's request parameters3. Parsing parameters from the request data4. Handling User Requests5. Generate Response Data6. Send request data using I/O flow to the client1, 2, 6 is universal, by the Web server completed, 3, 4, 5 There are differences, because different requests contain th

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

server uninstalls the Servet, for example, when the servlet has not been used for a long time ). What are the implicit objects in JSP pages )? What are their respective types and functions? Request --Reponse --Session --Application --Out --Page --Pagecontext --Exception -- it is valid only when the current JSP page is error page.Config -- What is the difference from What are the running Modes of

Servlets and jsp (preferred for SUN Enterprise Applications) Development Principles (II) Do not re-invent the wheel. Do not start from scratch: Custom components can improve reusability, but custom components still need to write, test, and Debug programs. The problem is that someone else may have done this, and your implementation method is not necessarily better than others. This isJsp (prefer

The main manifestation at two points1. JSP is a class servletJSP simple point is to use another set of simple rules written by the servlet program, it can write Java code, can also write HTML code, JAVASCRIPT,CSS and so on ..., However, the server side is first turned into a servlet program and then executed in the order in which the servlet executes.JSP is a simplification of servlets, the use of

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

sent to the server and sent to the client by the server. Unlike CGI, the servlet does not generate a new process, but rather is in the same process as the HTTP server. It reduces the cost of the server by using threading technology. The servlet processes the request by invoking the service method when a request is received from the client, in which the servlet first determines what type of request is coming (Get/post/head ...). , and then calls the a

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 ("

use the XML Deployment profile (DD) to configure security without having to hard-code it into the Servlet class code.5.JSP support: Responsible for translating JSP code into real java.P.S: How does a container handle a request? P42A city servlet can have 3 names1. URL name that the customer knows2. The password internal name that the Deployer knows3. The actual fully qualified nameEstablishing a mapping of

safety, servlet Lifecycle management, JSP support and logging, and so on. We don't need to write anymore, we just need to call the method.The process of distributing the request is as follows, although I don't think I need it.Mapping of 2.2 servletHow did Tomcat find the servlet?You can use XML attribute mappings to findServlet file path name under Web-inf's classes, the generic servlet has 3 names URL name The secret internal name, whic