Software architecture

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One 、 Common software system architecture B/S、C/S

1.1C/S

• C/S The structure is the client / The server （Client/Server）, for example QQ;

• You need to write server-side programs , And client programs , For example, what we install is QQ Client program ;

• shortcoming ： When updating the software, both the client side and the server side need to be updated at the same time , More trouble ;

• advantage ： The security is better .

1.2　B/S

• B/S The structure is the browser / The server （Browser/Server）;

• advantage ： Just write a server-side program ;

• shortcoming ： Poor safety .

Two 、WEB resources

2.1　Web Resource introduction

• html/CSS/JS/ picture …： Static resources ;

• JSP/Servlet： Dynamic resources .

Of course , except JavaWeb Program , There's more Web Program , for example ：ASP、PHP etc. .

2.2

2.3 visit Web resources

Open the browser , Input URL：

The name of the agreement :// domain name : port / route , for example ：http://www.baidu.com:80/index.html

3、 ... and 、Web The server

Web The role of the server is to receive requests from clients , Respond to the client .

about JavaWeb It's just a program , There needs to be JSP/Servlet Containers ,JSP/Servlet The basic function of container is to convert dynamic resources into static resources , Of course JSP/Servlet Containers have more than these functions , We will learn bit by bit later .

What we need to use is Web The server and JSP/Servlet Containers , Usually the two come together . The following is true. JavaWeb The server ：

• Tomcat（Apache）：Apache The Fund , Small and medium sized JavaEE The server , Only a small number of JavaEE standard servlet/jsp. Open source , Free of charge

• JBoss（JBOSS）： Large scale JavaEE The server , Support all JavaEE standard , Rechargeable .

• Weblogic（Orcale）： Large scale JavaEE The server , Support all JavaEE standard , Rechargeable .

• Websphere（IBM）：IBM company , Large scale JavaEE The server , Support all JavaEE standard , Rechargeable .

JavaEE：Java Language is the sum of the technical specifications used in enterprise development , It's stipulated that 13 It's a big specification