Javaweb study summarizes the first--Initial knowledge javaweb

Javaweb Study Summary (i)--First knowledge javaweb

One: web-related Concepts

Web programs are generally referred to as Web sites, consisting of servers, client browsers, and networks. The advantage of Web programs is simple to use, do not need to install, learn, there is a computer, a network cable can be used.

1: Two modes of application: b/S and C/s

c/S is a client/server-side (server) application, which means that the application is generally run independently. b/S is the browser-side (Browser)/server-side applications, which are generally borrowed from IE, Firefox and other browsers to run. Web applications are generally b/s mode.

2:web Development Background Knowledge

Before learning web development, we must understand the background of web development and how Web programs work. When we visit the Web page, what happens to the browser and server, how does the website implement the request and response function? Let me briefly explain the entire process of browser access to the server.

(1) The user opens the browser on the local computer (ie,360, Firefox, etc.), enter the URL address of the website to be visited, this address tells the Web server which host we want to access.

(2) After the browser finds the specified host, it makes a request to the Web server.

(3) After the Web server receives the request, the corresponding processing is made, and the result is returned to the browser.

(4) After the browser has returned the result, the result of the response is displayed in the browser, which is the page we often see.

II: JAVAWEB Development Environment

When we build the Javaweb development environment, we first need to install the SDK JDK, Web server, database, and IDE (integrated development environment), below, a brief introduction to these tools.

1. Developer Kit JDK

A development environment for building applications, applets, and components published on the Java platform that provides an environment for writing Java programs and running Java programs. Simply put, if you are developing a Java program, you must use the JDK.

Main folders in the JDK:

Bin: Provides JDK tool program

DB:JDK comes with a lightweight database

Include: Storing files for local methods

LIB: A class library file that holds Java

JRE: Storing Java Runtime environment files

The main executable program in the JDK:

Javac:java compiler to convert Java code to bytecode

The Java:java interpreter executes the Java application byte code directly from the class file.

The Jdb:java debugger allows you to execute the program and examine the variables row by line.

Javah: Generates a C procedure that can invoke a Java procedure, or a header file that can be called by a Java program

2 Web Server

A Web server is a server that builds a basic platform for many applications, such as information publishing, data querying, and data processing, so that all users in the network can be accessed through the browser only if the developed Web application is placed in it. The most common Web server is the Tomcat server.

Workflow for Web servers:

(1) A Web browser sends a Web page request to a specific Web server.

(2) When the Web server receives a Web page request, it performs the corresponding function.

(3) Send the result of the user request to the user's Web browser in the form of a Web page.

3 Database

The database is essential when developing a dynamic Web site, as the name implies, and the database is primarily used to store information in the site. Common databases are Oracle (for large Web sites), SQL Server, or MySQL (for medium web sites) and access (for small sites).

4 integrated development environment IDE

The Ides developed by the Javaweb program are more common: Eclipse, myeclipse, and IntelliJ idea.

Three: Introduction to Tomcat server

In Javaweb, Web applications require support from the Web server. With its free and cross-platform features, Tomcat became the first choice for Javaweb learning and development.

Individual folders in the Tomcat directory:

Bin: A script file that launches and closes Tomcat under each platform, Two of the most important files are Startup.bat and Shutdown.bat, which are files that start Tomcat in a Windows environment, which is a file that closes tomcat in a Windows environment

Conf:tomcat configuration files, such as Server.xml and Web. XML, etc.

LIB: Jar files that are accessible to Tomcat and all Web applications

Logs: Log file that holds Tomcat

Work:tomcat parsing JSP-generated servlet files in this directory

Four: Javaweb

So much has been said, what exactly is Javaweb? Javaweb is a generic term that uses Java technology to solve problems related to the web domain. Java is widely used in Web server applications, such as Jsp,servlet and third-party frameworks.

Now, Javaweb needs the tools, and after the installation is complete, we can use our hands to knock out the wonderful Javaweb program. Come on!

Javaweb study summarizes the first--Initial knowledge javaweb