It is better to have Chinese translation of foreign papers about dcs.

Let's start this chapter by defining the term web application. We've all seen ordinary people.

Client application, but what is a web application? Loosely speaking, it can be defined as

An application running on a server, accessed by users through a thin general-purpose client.

Today, the most common client is a web browser on a PC or workstation, but other types

Customers are rapidly joining the ranks, such as wireless PDA, mobile phone and other special equipment.

Equipment.

The lofty goal here is from any type.

The device right in front of you. This means that the same simple client program

Must be able to talk to many different server applications, and these applications must be able to

Dealing with many different types of customers. In order to meet this demand, the client

The dialogue between the server and the server must be defined in detail. This is hypertext.

The transport protocol (HTTP) is applicable to.

The communication model defined by HTTP forms the basis of all web applications.

Design. The basic understanding of HTTP is to develop suitable.

Protocol constraints, no matter which server-side technology you use. In this chapter,

Let's take a look at the most important details of HTTP that you need to know as a web application.

Developers.

Another thing: This book is about using JSP as a server-side technology, so this is what we are going to do.

Focus on As you can see in chapter 1, JSP is based on Java servlet technology. both

There are many common terms and concepts in various technologies, so it is helpful to know a little about servlets.

You can even develop pure JSP applications. Really understand and use the complete

The power of JSP, you need to know something about servlets. Therefore, we will look at servlet.

The basics of the last section of this chapter.

A server that uses the specified protocol. The HTTP request message consists of three parts: one

Request line, request header, and possibly request body.

The request line starts with the request method name, followed by the resource identifier and.

Protocol version used by the browser:

GET /index.html HTTP/ 1.0

The most commonly used request method is called GET. As the name implies, GET requests

Used to retrieve resources from the server. This is the default request method, so if you type

URL, or click a link and the request will be sent as a GET request.

To the server.

The request header provides additional information that the server can use to process the request.

The message body is only contained in certain types of requests, such as the POST request we discussed.

We'll talk about it later.

The following is an example of a valid HTTP request message: