web.xml (1) - common elements of web.xml configuration file and their meaning preview

1  < web-app > 
2  
3       <!-- Define the name of the WEB application --> 
4       < display-name ></ display-name > 
5  
6       <!-- Declare the description information of the WEB application --> 
7       < description ></ description > 
8  
9       <!-- The context-param element declares application-wide initialization parameters --> 
10       < context-param ></ context-param > 
11  
12       <!-- The filter element will have a name Associated with a class that implements the javax.servlet.Filter interface --> 
13       < filter ></filter > 
14  
15       <!-- Once a filter is named, associate it with one or more servlets or JSP pages using the filter-mapping element --> 
16       < filter-mapping ></ filter-mapping > 
17  
18       <!-- Version 2.3 of the servlet API added support for event listeners, which are notified when a session or servlet context is created, modified, and deleted.
19           The Listener element indicates the event listener class --> 
20       < listener ></ listener > 
21  
22       <!-- When making initialization parameters or custom URLs to a servlet or JSP page, you must first name the servlet or JSP page.
23           Servlet element is used to accomplish this task --> 
24       < servlet ><
25  
26       <!-- The server generally provides a default URL for the servlet: http://host/webAppPrefix/servlet/ServletName.
27           However, this URL is often changed so that the servlet can access initialization parameters or handle relative URLs more easily.
28           When changing the default URL, use the servlet-mapping element --> 
29       < servlet-mapping ></ servlet-mapping > 
30  
31       <!-- If a session is not accessed for a certain period of time, the server can discard it to save memory. The timeout value for a single session object can be set explicitly by using HttpSession's
 32           setMaxInactiveInterval method, or a default timeout value can be specified using the session-config element --> 
33       < session-config ></ session-config > 
34  
35       <!--If a web application has specific files it wants to be guaranteed to be assigned a specific MIME type, the mime-mapping element provides this guarantee --> 
36       < mime-mapping ></ mime-mapping > 
37  
38       <!-- Instructs the server which file to use when it receives a URL that refers to a directory name instead of a file name --> 
39       < welcome-file-list ></ welcome-file-list > 
40  
41       <!-- when returning a specific HTTP status When you code, or when a specific type of exception is thrown, you can specify the page to be displayed --> 
42       < error-page ></ error-page > 
43  
44       <!-- For Tag Library Descriptor file) to specify an alias. This feature enables you to change the location of TLD files
 without           editing the JSP pages that use these files -->
      < taglib ></ taglib > 
47  
48       <!-- Declare a resource-related management object --> 
49       < resource-env-ref ></ resource-env-ref > 
50  
51       <!-- Declare a resource factory External resources used --> 
52       < resource-ref ></ resource-ref > 
53  
54       <!-- Make URLs that should be protected. It is used in conjunction with the login-config element --> 
55       < security-constraint ></ security-constraint > 
56  
57       <! --Specify how the server should authorize users trying to access protected pages. It is used in conjunction with the security-constraint element -->
58       < login-config ></ login-config > 
59  
60       <!-- Gives a list of security roles that will appear in the role-name subelement of the security-role-ref element within the servlet element.
61           Declare roles separately to make it easier for advanced IDEs to handle security information --> 
62       < security-role ></ security-role > 
63  
64       <!-- declare environment entries for web applications --> 
65       < env-entry ></ env-entry > 
66  
67       <!-- Declare a reference to the EJB's home directory --> 
68       < ejb-ref ></ ejb-ref > 
69  
70       <!Declare an EJB's local home directory application --> 
71       < ejb-local-ref > </ ejb-local-ref > 
72  
73   </ web-app >