Guoxing An East Camp Notes 1

Wangmai CRM system development

1. Scripting: closer to the bottom layer, better performance, python

2. Visualization: close to the surface, software interface, etc., java

3. JavaScript: As an auxiliary language, so is python

4. TIOBE language rankings.

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5. Difficulty analysis of CRM system

1. All software development systems have three common difficulties: first, the realization of technical complexity, second: the realization of business complexity, and third: the amount of data.

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Supplement: tomcat problem:

1. The core port of tomcat, how many threads does tomcat have, how to optimize, how to use the things in each folder, and how to configure?

2. Spring's IOC container design.

7. Technical framework used:

1. JAVAEE、JAVASE

   Important: SpringMVC (mainly completes the request, acceptance, forwarding, and data response return scheduling of WEB pages),

Spring (Kernel Mechanism System-Heart),

Mybatis (data persistence layer-main communication between database and code)

1. Two open methods

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2. WEB service, (agent mapping peanut shell)

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1. Tomcat directory structure:

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   1. Startup use: Run startup.bat in the bin directory to run tomcat. The prerequisite for using tomcat is to configure the jdk environment.

   2. Port 8005 is closed by default

       <Server port="8005" shutdown="SHUTDOWN">

   3. Start port 8080 by default

       <Connector port="8080" protocol="HTTP/1.1"
                      connectionTimeout="20000"
                      redirectPort="8443" />

   4. Communication port default 8009

        <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

   5. When tomcat starts, you need to check whether both ports are occupied, one is to close the port, and the other is to start the port.

   6. Tomcat allows to modify the port, but try not to modify the port below 5000, because most of those are operating system ports.

   7. Tomcat's three important configuration files server.xml web.xml context.xml.

      1. Even if the web.xml in the javaSpring project is deleted, as long as the configuration file web.xml in the tomcat is still normal, the project can still be started. Among them, conf/web.xml in tomcat is the default configuration file, which is the default.

      2. Three startup welcome pages are set by default in web.xml, which can be accessed only after startup.

             <welcome-file-list>
                  <welcome-file>index.html</welcome-file>
                  <welcome-file>index.htm</welcome-file>
                  <welcome-file>index.jsp</welcome-file>
              </welcome-file-list>

         It should be noted that if there are multiple welcome pages, then jump to the place where the first match is checked, and no longer match other welcome pages.

2. 7, 2, 1 ratio: 7 backends, two frontends, and one UI.

   tomcat continues:

   1. localhost:8080The path corresponds to the ROOT directory under the webapps folder localhost:8080/loginin tomcat ; it corresponds to the login directory under the webapps folder in tomcat.

   2. HTTP Status 404-Not Found: It means that the specified page cannot be found.

      HTTP Status 500-Not Found: Represents java syntax error.

   3. Jar package: It is the driver package, which is a rule formulated by Java itself. The jar package can be opened with a compression tool. It contains a package package (in fact, many class files, which can be opened by the decompiler tool), which can be opened by calling the path of import. Simply put, the synthesis of countless class files is the jar package.

   4. The servlet package is very important, which contains the running sequence and working mechanism of the MVC framework.

   5. The making and calling of jar package, the making and calling of war package.

   6. The user visits index.jsp -> tomcat, the jsp page is parsed into the index_jsp.java file

      -> Compile this java file into index_jsp.class file

      -> Display the output result of class file execution to the user

      -> What the user sees is a virtual web page

      Through the above process, it is found that the security of JSP is very high, NetEase is virtual, and the most secure in the front end.

   7. The user visits index.html -> the web server directly sends the html file to the user's browser

      -> Analyze and display through the user's browser

      -> html (weak language) cannot be attacked

      Mainstream large platforms use html static pages throughout.