J2ee notes-basics

Level 1 network function (Layer 8): LAN/ATM (physical layer) ---- LAN/ATM (Data Link Layer) ---- IP (network layer) ---- TCP/UDP (Transport Layer) ---- session layer ---- presentation layer ---- HTTP (application layer) ---- SOAP/UDDI (Web service ).
J2EE architecture:
The container contains three main Java Web programming technologies:
1) J2EE application component-Servlet, JSP, EJB (jdk, j2eedk)
2) Application services provided by J2EE-JDBC (data connection technology), JTS (), JNDI (naming technology), data transaction technology, security technology, connection framework Technology ,, web service technology and deployment technology (deployment) to ensure and promote the good running of components.
3) application traffic technology-RMI, JMS, JavaMail, Web protocol, remote method call, Object Management Group protocol, Java communication service technology, Java Message technology and mail technology, at the underlying layer of the platform, information is transmitted between machines and programs.
2. HTTP provides two Form and server request methods: Get method (webpage location URL, body of the sent content body, and sending at the same time) and Post method (first URL and then body)
Three HTML form useful attributes: action, method (specify the HTTP method for sending data to the server), enctype (specify the encoding method before the data is sent, the default value is application/x-www-form-urlencoded or multipart/form-data (using the post method). target (specifies the frame in the browser to display the server's response html, the default value is the current frame), onsubmit and onreset, accept and accept-charset (specify the MIME type and character encoding type accepted by the server program ).
Four System configuration settings: after jdk is installed, set Java_home = j2sdk installation directory (c: jdk1.4), classpath = % java_home % in
After the web server is installed, set (for example, to start the service using the command line) catalina_home = web service installation directory,
Web server folder description: % catalina_home % in, % catalina_home % common -- Java class files and jar files used by the Web server, internal classes folder class files, endosed stores external jar files, and lib stores the jar files used by the server and all web programs. % Catalina_home % conf -- web Service Configuration server. xml. % Catalina_home % logs, % catalina_home % emp, % catalina_home % webapps -- web application.
5. Convert basic servlet into API: javax. servlet (provides basic servlet classes and interfaces that can be used by Web containers) directory and javax. servlet. http Directory (including servlet interfaces related to http ).
Http requests consist of three parts: 1 request line-request method, request Url and protocol
2 headers-multiple attributes (For more information, see http 1.0)
3. The text or binary file attached to the data body after the request.