In ASP.NET this is represented as the Response object. When the Web server responds to a request, the communication is typically in the following text-based format:
1.HTTP/1.1 200 OK 2.Server: Microsoft-IIS/6.0 3.Content-Type: text/html 4.Content-Length: 38 5.<html><body>Hello, world.</body><html>
The first line contains the protocol and version information, plus a status-code and reason.
|
Status-Code Description |
Group |
|---|---|
|
1xx |
Informational: Request received, continuing to process. |
|
2xx |
Success: The action was successfully received, understood, and accepted. |
|
3xx |
Redirect Command: Further action must be taken in order to complete the request. |
|
4xx |
Client Error: The request has a syntax error or the server does not know how to fulfill the request. |
|
5xx |
Server Error: The server failed to fulfill a request that appears to be valid. |
In addition to the status-code groups, HTTP/1.1 defines unique status-codes and reasons. (A reason is nothing more than a very brief description of the status-code.)
|
Status-Code |
Reason |
|---|---|
|
100 |
Continue |
|
200 |
OK |
|
201 |
Created |
|
300 |
Multiple Choices |
|
301 |
Moved Permanently |
|
302 |
Found |
|
400 |
Bad Request |
|
401 |
Unauthorized |
|
403 |
Forbidden |
|
404 |
Not Found |
|
407 |
Proxy Authentication Required |
|
408 |
Request Time-out |
|
413 |
Request Entity Too Large |
|
500 |
Internal Server Error |
|
501 |
Not Implemented |
The second line of the response indicates the type of Web server.
The third line (Content-Type) indicates the type of resource that is being sent to the Web browser. This indicator is in the form of a Multipurpose Internet Mail Extensions (MIME) type. In this case, the file is a static HTML text file. The MIME type is a two-part designator "type/subtype," in which the first part is the resource type and the second part is the resource subtype.
|
MIME Type |
Description |
|---|---|
|
text |
Textual information. No special software is required to get the full meaning of the text, aside from support for the indicated character set. One subtype is plain, which means that the text can be read without requiring additional software. Other subtypes are html and xml, which indicate the appropriate file type(s). |
|
image |
Image data. Requires a display device (such as a graphical display or a graphics printer) to view the information. Subtypes are defined for two widely used image formats, jpeg and gif. |
|
audio |
Audio data. Requires an audio output device (such as a speaker or headphones) to "hear" the contents. An initial subtype called basic is defined for this type. |
|
video |
Video data. Requires the capability to display moving images, typically including specialized hardware and software. An initial sub-type called mpeg is defined for this type. |
|
application |
Other kinds of data, typically either uninterpreted binary data or information to be processed by an application. The subtype, called octet-stream, is to be used in the case of uninterpreted binary data, in which the simplest recommended action is to offer to write the information into a file for the user. The PostScript subtype is also defined for the transport of PostScript material. |
| More Info |
MIME Types The registry contains a list of MIME types/subtypes at the following location: HKEY_CLASSES_ROOT\MIME\Database\Content Type. |
After the content-length line, the response message is returned. This message is based on the MIME type. The browser attempts to handle the message based on its MIME type.