Jsp tags, Fields

 

1. Jsp labels are the logical business functions provided, so you can avoid writing java code in jsp. The main labels are

<Jsp: include page = ""> </jsp: include> Other jsp files can be included in double quotation marks.

<Jsp: foward page = ""> </jsp: iorward> jump to the tab jump page. You can directly add

<Jsp: parma value = "" name = ""> </jsp: prma> You can directly add a value to the double quotation marks for the value transfer tag, which must be used with the foward tag.

2. What is the difference between dynamic and static introduction?

<Jsp: include> when two jsp files are involved in the dynamic label introduction, the files are translated into two servlets and merged for execution.

Include is the two jsp files involved in the static import and will be translated into a servlet. The two files are merged in the source file for execution.

3. jsp ing jsp

Jsp ing jsp is to introduce html files in jsp. The ing syntax is

<Servlet>

<Servlet-name> *** </servlet-name>

<Jsp-file> *** </jsp-file>

<Load-on-startup> *** </load-on-startup>

</Servlet>

<Servlet-mapping>

<Servlet-name> *** </servlet-name>

<Url-pattern> *****. html </url-pattern>

</Servlet-mapping>

 

Add an html file to map jsp

4. Objects in four domains

Pagecontext (page domain)

Request (request domain)

Session)

Servletcontext (application domain)

1. What is a domain?

Is the scope of the function.

2. What is the lifecycle of these four domains?

The page field is valid only on the current page and ends when you leave the page.

After the request domain sends the request,

The session domain is a session and ends after a session is completed.

The application domain is the entire web application.

3. When to use the object domain

If the page field is valid on the current page

When the request domain is used up by others

The session domain can be used by itself after a period of time.

When the Application domain is used by itself, not only can it be used by yourself, but also by others

 

 

Author: hj714886063