There are 5 differences in the Get post submission form in the ASP tutorials _ Application Tips

Source: Internet
Author: User
Tags html header http post http request php tutorial alphanumeric characters browser cache
The following 5 points are distinguished from the Get post submission form in the ASP tutorial

the difference between get and post means 5 points
1. Get is to obtain data from the server, post is to transfer data to the server.
2. Get is to add the parameter data queue to the URL of the action attribute that submits the form, and the value corresponds to each field one by one in the form, which can be seen in the URL. Post is the HTTP post mechanism that places the fields in the form and their contents in the HTML header to the URL address that the action attribute refers to. This process is not visible to the user.
3. For Get way, server end uses Request.QueryString to obtain variable value, for post way, server end uses Request.Form to obtain the submitted data.
4. The amount of data transferred by get is small and cannot be greater than 2KB. Post transfers have a large amount of data, which is generally default to unrestricted. In theory, however, the maximum number of IIS4 is 100KB in 80KB,IIS5.
5. Get security is very low, post security is high.

HTTP request: Difference between get and post methods
HTTP defines different methods of interacting with the server, and the most basic method is get and POST. In fact, get applies to most requests, while the reserved POST is used only for updating the site. According to the HTTP specification, get is used for information acquisition, and should be secure and idempotent. The so-called safe means that the operation is used to obtain information rather than modify information. In other words, get requests should not generally have side effects. Idempotent means that multiple requests to the same URL should return the same result. The complete definition is not as strict as it seems. Fundamentally, the goal is that when a user opens a link, she can be sure that it doesn't change resources from its perspective. For example, the front pages of news sites are constantly being updated. Although the second request returns a different batch of news, the operation is still considered safe and idempotent, as it always returns the current news. Vice versa. POST requests are not that easy. POST represents a request that might change resources on the server. Still, for example, a news site, the reader's note to the article should be implemented through post requests, because the site has been different after the annotation was submitted (for example, an annotation appears below the article);
When a form is submitted, if method is not specified, the default is GET request, and the data submitted in the form is appended to the URL to separate it from the URL. Alphanumeric characters are sent as is, but spaces are converted to "+", and other symbols are converted to%XX, where XX is the ASCII (or ISO Latin-1) value that the symbol is in 16. A GET request requests that the data submitted be placed in the HTTP request protocol header, while the data submitted by the post is placed in the Entity data, and the Get method submits data with a maximum of 1024 bytes and the post does not have this limit.

What's the difference between using "post" and "get" in a form?
In the form, you can use the post or get. They are all valid values of method. However, the post and get methods are at least two different points of use:
1. The Get method passes the user's input through a URL request. The Post method is in another form.
2, get way of the submission you need to use Request.QueryString to obtain the value of the variable, and the Post method submission, you have to pass through Request.Form to access the content submitted.
Study the following code carefully. You can run it to feel the following:
Code
The following are the referenced contents:
<!--two form only the method attribute is different-->
Copy Code code as follows:

<form action= "getpost.php tutorial" method= "Get" >
<input type= "text" name= "text" value= "Hello World" ></INPUT>
<input type= "Submit" value= "Method=get" ></INPUT>
</FORM>
<BR>
<form action= "getpost.php" method= "POST" >
<input type= "text" name= "text" value= "Hello World" ></INPUT>
<input type= "Submit" value= "Method=post" ></INPUT>
</FORM>

? If request.querystring ("Text") <> "" Then?>
The string passed through the Get method is: "<b><?= request.querystring (" Text ")?></b>" <BR>
? End If?>
? If Request.Form ("Text") <> "" Then?>
The string passed through the Post method is: "<b><?= request.form (" Text ")?></b>" <BR>
? End If?>

Description
Save the above code as getpost.asp, then run, first test the Post method, at which point the browser URL does not change, the result returned is:
The string passed through the Post method is: "Hello World"
Then the test is submitted using the Get method, notice that the URL of the browser becomes:
Http://localhost/general/form/getpost.php?Text=Hello+World

and the result of the return is
The string passed through the Get method is: "Hello World"
Finally, the Post method is submitted, and the URL of the browser is:
Http://localhost/general/form/getpost.php?Text=Hello+World

and the return result becomes
The string passed through the Get method is: "Hello World"
The string passed through the Post method is: "Hello World"

Tips
Submitting data through a GET method can pose a security issue. Like a landing page. When data is submitted through the Get method, the username and password appear on the URL. If:
1, landing page can be browser cache;
2, other people can access the customer's machine.
Then, someone else can read the account number and password from the browser's history. Therefore, in some cases, the Get method poses a serious security problem.

suggested
In the form, it is recommended that you use the Post method.
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