Comparison of syntax and object: view the convertible functions of ASP and JSP

We will illustrate through the comparison between ASP and JSP syntaxes and objects, the conversion from ASP to JSP can be achieved.

Hidden objects of ASP and JSP

Application Object: Share the current Application information among all users.

 
 

  
  
< % Dim ls_write  
  
  
For Each Key in Application.Contents  
  
  
 ls_write = Key + ":"+Application(Key)  
  
  
 Next  
  
  
%> 
  
  
         
 
 

Config Object: stores servlet configuration information, but is rarely used.

Function	ASP	JSP
Object Name	ASP does not have similar objects	Config
Object Type	N/	Javax. servlet. ServletConfig
Servlet name	N/	GetServletName
Returns the servlet initialization parameter name.	N/	GetInitParameterNames ()
Obtain the initial parameter value.	N/	GetInitParameter (String name)

Error Object: any Error information contained in the script

Function	ASP	JSP
Object Name	ASPError	Exception
Object Type	N/	Java. lang. Throwable
Special note	In the latest ASP3.0/IIS5.0 object, you can use Server. GetLastError to obtain the ASPError object.	Only when the page is defined as an error page can it be obtained. You can use the following statement: <% @ Page isErrorPage = "true" %>
Error Message	Description ()	GetMessage ()
Get all errors	ASPDescription ()	ToString ()
Error Tracking	N/	PrintStackTrace (out)
Error location	LineColumn	N/

Out: used to write and control the output cache from the server to the browser

Function	ASP	JSP
Object Name	Response	Out
Object Type	N/	Javax. servlet. jsp. JspWriter
Write Data to the output Cache	Write variant	Print (object or primitive data type)
Write binary data	BinaryWrite data	This method must be used through the java OutputStream class. ServletOutputStream Output = response. getOutputStream (); Output. write (Btye [] buffer );
Clear out Cache	Clear	ClearBuffer ()
Send the current cache to the client	Flush	Flush ()
Stop processing the current page	End	Close () This is different from end. It closes the current output stream, and the JSP page will still process it.

Request Object: accept information from the client browser.

Function	ASP	JSP
Object Name	Request	Request
Object Type	N/	Is a subclass of javax. servlet. ServletRequest Usually javax. servlet. HttpServletRequest
Cookie details	Cookies [(key). attribute]	Cookie [] = getCookies ()
Obtain table data	String = Form (element) [(index)] For example: mydata = Request. Form ("date ")	String = getParameter (Name) Enum = getParameterNames () string [] = getParameterValues (name) For example: ls_form = request. getParameter ("date ");
Retrieve query data	QueryString (element) [(index) |. Count]	GetParameter (Name) getQueryString () (entire query string)
HTTP header sent by the client	ServerVariables (server environment var) For example: ServerVariables (ALL_RAW) returns to you all the headers in raw format	GetHeaderNames () getHeader (name) getHeaders (name) getIntHeader (name) getDateHeader (name)

Response Object: send information to the browser. ASP and JSP treat response objects differently. ASP only uses the Response object to control the output to the browser. JSP separates this function into two objects. In JSP, Response is the actual object sent to the client. JSP also uses an out object to write data to the output cache.

Function	ASP	JSP
Object Name	Response	Response
Object Type	N/	It is a subclass of javax. servlet. ServletResponse. It is usually used: javax. servlet. HttpServletResponse
Cache page output	Buffer = True/False	The page cache of JSP is usually 8 K. You can set the cache size. The following example shows how to disable the cache <% @ page buffer = "none" %>
Enable/disable Proxy Server Cache	CacheControl = Private/Public	SetHeader ("Pragma", "no-cache") setHeader ("Cache-Control", "no-cache ")
Add Cookie	Cookies [(key). attribute] = value	AddCookie)
Add Http Header	AddHeader Name, Value	SetHeader (Name, Value)
Connect the client to another page	Redirect URL	SendRedirect (Absolute URL)
Send error message to client	N/	SendError (int code, String msg)
Set the output MIME type	ContentType = "mime type"	SetContentType ("mime type ")

Server Object: Provides connections to methods and attributes on the Server.

Function	ASP	JSP
Object Name	Server	JSP does not have Server objects. Functions in ASP Server objects have been assigned to other pages.
Object Type	N/	N/
Create an object on the server	CreateObject (Object id)	N/
Encode a String in HTML format.	HTMLEncode (String)	N/
Search for files through absolute path	MapPath (Path)	N/
Encode the URL	URLEncode (String)	N/
Set timeout	ScriptTimeout = Seconds	N/

Session Object: share information between multiple pages for a user.

Function	ASP	JSP
Object Name	Session	Session
Object Type	N/	Javax. servlet. http. HttpSession
Note:	ASP uses session through cookie	JSP has two session management methods: 1. Use cookies 2. Use URL rewriting
Close the session and release its resources	Abandon	Invalidate ()
Store a session variable	Session (String name) = "Your Data"	SetAttribute (String name, Object object )*
Store a session Object	Set Session (String name) = Server. CreateObject (String name)	Same as above
Get a session variable	My_Variable = Session (String name)	GetAttribute (String name )*
Obtains a session object.	Set My_Object = Session (String name)	Same as above
Deletes an object or variable of a session.	Contents. Remove (String name)	RemoveAttribute (String name)
Collect content	Contents	GetAttributeNames ()
Session ID	SessionID	String = getId ()
Set timeout	Timeout (Minutes)	SetMaxInactiveInterval (int interval in seconds)
Get timeout settings	N/	Int = getMaxInactiveInterval ()
Disable session	<% @ EnableSessionState = False %>	<% @ Page session = "false" %>

ASP and JSP scripts

Script Declaration: how to split the server script from the client script.

ASP	JSP
<% Your Server Side Script %>	<% Your Server Side Script %>

Expression: send data directly to the output cache.

ASP	JSP
<% = Your_Variable %>	<% = Your_Variable %>

Declaration: declare variables and methods so that they can be used on this page.

ASP	JSP
<% Your Function %>	<%! Your Function %>

ID: Tell the container how to process this page,

ASP	JSP
<% @ Your Directive %>	<% @ Your Directive %>
For example, set the script language: <% @ LANGUAGE = "VBSCRIPT" %> Another example is: <% Response. buffer = true %>	ID to send information to container The identifier does not send messages to the output cache. When the JSP page is initialized, the ID is processed For example, set the script language: <% @ Page language = "java" %> Another example is: <% @ Pagebuffer = "64 k" autoFlush = "true" %>

Script notes:

Annotation type	ASP	JSP
General Comment	<% 'Your Comment %>	Java notes: <% // My comment %> or <%/* my comment */%>
Specific annotations	N/	JSP comments: <% -- Your comment -- %> This type of annotation is not processed in the container or in the servlet.

Introduction file of ASP and JSP

Introduction: Before the page is not processed, introduce the file

ASP	JSP
<! -- # Include file = "Your File. asp" --> <! -- # Include virtual = "/Your File. asp" -->	<% @ Include file = "Your File" %> <Jsp: directive. include file = "Your File" %>

ASP and JSP File Transfer

ASP	JSP
Response. redirect ("to_File.asp ")	Response. sendRedirect ("to_File.asp ")

1. Technical Comparison of ASP and JSP Functions
2. How to add a web framework in Servlet
3. What are servlets and common Servlet APIs?
4. At the beginning of JSP Servlet Development
5. Java Servlet API documentation