ASP tutorial: 11th ASP Built-in Object Server

Through the first nine of the theory and practice, I believe that we have a systematic understanding of ASP, although so far, we have only learned the ASP's 4 built-in objects, but has been able to write a number of practical small programs. Today, the author will continue to explain to you the last ASP built-in object--server.

Before I begin this course, I will still be here to answer some of the more general questions raised by my friends. There are still a lot of letters from friends asking me how to build a server-side Active server Page environment. I think I have not made it clear in the previous few, so it is necessary to elaborate on this issue at the beginning of this article.

The ASP application is based entirely on Microsoft Internet infomation Server (IIS), and IIS has two versions for Windows NT server and WorkStation (of course IIS4.0 also has Windows98 version, this is not mentioned here, its function is almost identical, the difference is just the installation process. Generally speaking, we are using the IIS version on the NT server. In an NT Server environment, publishing information and managing sites are generally done through IIS. Normally we run the IIS2.0 version in the NT4.0 version, but it does not have the functionality to support ASP. The ASP must be installed separately after installing IIS, the installation file is a Microsoft Release ASP installation package, about 9 trillion, should be able to download on Microsoft's website. When the IIS2.0 feature is added to support ASP, it is automatically upgraded to version 3.0. 2.0 and 3.0 for the WEB server, there is no major changes, but simply increased the ability to run ASP. When the installation is complete, run Internet Services Manager, and you will see the following screen:

　

There are three kinds of services available in IIS3.0: WWW, Gopher, ftp,www service to submit WEB pages for client browsers, and allow customers to access. asp files. Of course, you can install the latest IIS4.0 version directly, and the authors recommend that you install this version because it has a stronger WEB management and security. There has been a fundamental change in the management interface of IIS in IIS4.0, and the familiar Internet Service manager has been replaced by Microsoft Management console, referred to as MMC. Its interface is shown below:

So how do you install IIS4.0? When installing IIS4.0 on NT4.0, you must have NT SP3 installed on your system, as well as Internet Explorer4.01, note that the version of Internet Explorer here must be 4.01 and the version number is 4.72.3110.8. This is important, otherwise you will not be able to install IIS4.0. In order to install this version, the author deliberately spent one night upgrading the IE version on Microsoft's site.

IIS supports virtual directories, which can be managed by the Directory tab in the Server Properties dialog box. Establishing a virtual directory is very important for managing WEB sites. First, the virtual directory hides important information about the site directory structure. Because in the browser, the customer can easily get the file path information of the page by selecting "View Source code", and if the physical path is used on the WEB page, it will expose important information about the site directory, which could easily cause the system to be attacked. Second, as long as two machines have the same virtual directory, you can move the WEB page from one machine to another without making any changes to the page code. Also, when you place a WEB page in a virtual directory, you can set different properties for the directory, such as Read, Excute, Script. Read access represents the delivery of directory content from IIS to the browser. and executing access enables executable files to be executed within that directory. When you need to use ASP, you must set the directory of your. asp files to "Excute". The author suggests that when you set up a Web site, placing HTML files in separate directories with ASP files, and then setting the HTML subdirectory to "read" and setting ASP subdirectories to "execute", not only facilitates the management of the WEB, but also the most important to improve the security of ASP programs and prevent The program content is accessed by the customer. Because at the end of July this year, IIS was found by some network masters a terrible bug, that is, when you are in a site of the. asp file after adding:: $DATA, customers will be able to see in the browser all the source code of the. asp file, which is very scary for a site. Of course, Microsoft has written a patch for this bug, but in order to completely eliminate this possibility, the author also suggested that you do not set the directory where the ASP is located to be readable.
I think that now you should have a full understanding of the ASP server-side settings, let's go to the business-learn the ASP's last built-in Object server.

The server object provides access to methods and properties on the server, where most of the methods and properties are serviced as functionality of the utility. With the server object, you can start ActiveX object routines on the server and use the Active Server service to provide functions such as HTML and URL encoding.

First, the grammar

Server.property|method

Second, the property

ScriptTimeout timeout value, which is timed out after the script runs beyond that time. The following code specifies that the server processing script times out after 100 seconds.

<% server.scripttimeout=100%>

It is worth noting that by using the AspScriptTimeout property in the metabase, you can set the default ScriptTimeout value for the Web service or Web server. The ScriptTimeout property cannot be set to less than the value specified in the metabase. For example, if Numseconds is set to 60, and the metabase setting contains a default value of 90 seconds, the script times out after 90 seconds.
Third, the method

1, HTMLEncode method

The HTMLEncode method allows you to encode HTML for a particular string, although HTML can display most of the text you write to the ASP file, but you will encounter problems when you need to actually include the characters used in the HTML tag. This is because when the browser reads such a string, it tries to interpret it. For example, the following text:
This is a test of the HTMLEncode method. < br> there should be no other line here.

will be displayed by the browser as:

This is a test of the HTMLEncode method.
There should not be another line here.

To avoid such problems, we need to use the HTMLEncode method of the Server object to replace the HTML tag character with the corresponding HTML Character Code that is not interpreted by the browser. So, use the following code to display the correct HTMLEncode string so that you can output text in your browser as you want.
<%
Response.Write Server.HTMLEncode ("This is a test of the HTMLEncode method.) < br> there should be no other line here. ")%>

2, UrlEncode method

Just as the HTMLEncode method enables the customer to translate strings into acceptable HTML formats, the Server object's UrlEncode method can encode the string correctly according to the URL rules and is not allowed in strings when the string data is passed to the server as a URL Spaces, and special characters are not allowed. To do this, you can use the Server.URLEncode method if you want to encode the URL before sending the string.
3, MapPath method

The MapPath method maps the specified relative or virtual path to the corresponding physical directory on the server.

The syntax is as follows: Server.MapPath (Path)

path Specifies the relative or virtual path to map the physical directory. If path starts with a forward slash (/) or backslash (\), the MapPath method treats the path as the full virtual path when it returns the paths. If path does not start with a slash, the MapPath method returns the path relative to the path already in the. asp file. It should be noted here that the MapPath method does not check whether the returned path is correct or exists on the server.

For the following example, file Data.txt and test.asp files containing the following scripts are located under the directory C:\Inetpub\Wwwroot\asp. The C:\Inetpub\Wwwroot directory is set to the server's host directory. The following example uses the server variable PATH_INFO to map the physical path of the current file. The following script
<%= Server.MapPath (Request.ServerVariables ("Path_info"))%>

Output

C:\inetpub\wwwroot\asp\test.asp

Because the path parameters in the following example do not start with a slash character, they are mapped relative to the current directory, which is the directory C:\Inetpub\Wwwroot\asp. The following script
<%= Server.MapPath ("Data.txt")%>
<%= Server.MapPath ("Asp/data.txt")%>

Output
C:\inetpub\wwwroot\asp\data.txt
C:\inetpub\wwwroot\asp\asp\data.txt

4, CreateObject method

Server.CreateObject is probably the most useful and powerful function of ASP. It is used to create an instance of an ActiveX component that has been registered to the server. This is a very important feature, because by using ActiveX components you can easily extend the ability to ActiveX, it is with ActiveX components that you achieve vital functions such as database connectivity, file access, ad display, and other VBScript Inability to provide or simply rely on functionality that can be accomplished by using ActiveX alone. It is because of these components that the ASP has a strong vitality.
The syntax is as follows:

Server.CreateObject ("Component Name")

By default, objects created by the Server.CreateObject method have page scopes. This means that after the current ASP page processing completes, the server will automatically destroy these objects. If you want to create an object that has a session or application scope, you can use the < object> to mark and set the SCOPE properties of the sessions or application, or you can store the object in a dialog and application variable. The following routine:
<% Set session ("ad") = Server.CreateObject ("MSWC.") AdRotator ")%>

Note here that you cannot create an instance of an object with the same name as the built-in object, otherwise, the following script will return an error.

<% Set Response = Server.CreateObject ("Response")%>

So far, we have learned the ASP all the built-in objects, do not know that everyone is not very excited? In fact, ASP is very simple, as long as we continue to practice, I believe that after a period of time is not difficult to become an ASP master. From the next article, the author will begin to introduce ASP built-in ActiveX components, which is a very important and practical part of ASP application. Please pay attention.