JAVA EE (brief)

I. Overview of the Platform

The full name of Java EE is Edition, a specification and standard for developing distributed enterprise-class applications.

Three versions of the Java platform:

• Java ME (Java micro Edition) Java mini-version
• Java SE (Java standard Edition) Java Standards Edition
• Java EE (Java Enterprise Edition) Java Business Edition

II. Overview of the architecture

Java EE server:

Java EE server provides deployment, management, and operational support for standards-compliant application components

Depending on the Java EE server, the application components can be divided into 3 classes.

• Deploy, manage, and run components on a Java EE server. (Web Components and EJB components)
• Deploy and manage components that are running on a Java EE server, but are loaded into the client. (Web resources for HTML pages and applets that embed pages)
• Deploy and manage components that are not fully defined in the Java EE specification. (Application client)

Iii. Overview of containers

Containers provide a running environment for Java EE application components.

The container provides a federated view from the underlying Java EE API to the application components.

Adding a container between the application component and the Java EE service allows the container to transparently inject the necessary services into the component.

A standard Java EE product provides a container for each application component type.

Container Overview:

A container is a collection of tools used to manage the behavior of a component, including interactions with the external environment, the lifecycle of components, cooperative dependencies between components, and so on.

Java EE container:

• Application Client Container: Contains component application client
• Applet container: Contains component applets
• Web Component container: Contains JSP and servlet components
• Enterprise Bean Container: The EJB container that contains the EJB components

Iv. Services

Overview: A service is an interface between a component and a container, and between a container and a Java EE server

V. Common Services

Jndi Get Data source

<ResourceAuth= "Container"Driverclassname= "Oracle.jdbc.OracleDriver"maxactive= "+"Maxidle= "+"Maxwaite= "10000"name= "Jdbc/jndi"Password= "ACCP"type= "Javax.sql.DataSource"URL= "Jdbc:oracle:thin: @localhost: 1521:orcl"username= "ACCP" />

/*** Get connections via Jndi*/     PublicConnection getconnection () {Connection conn=NULL; Try {            //declaring context ObjectsContext ct=NewInitialContext (); //declaring a data sourceDataSource ds= (DataSource) ct.lookup ("Java:comp/env/jdbc/jndi"); //Get Connectedconn=ds.getconnection (); } Catch(namingexception e) {e.printstacktrace (); } Catch(SQLException e) {e.printstacktrace (); }        returnConn; }

Mail

 Packagecom;Importjava.util.Properties;Importjavax.mail.Address;ImportJavax.mail.BodyPart;ImportJavax.mail.Message;ImportJavax.mail.Multipart;Importjavax.mail.Session;ImportJavax.mail.Transport;Importjavax.mail.internet.InternetAddress;ImportJavax.mail.internet.MimeBodyPart;ImportJavax.mail.internet.MimeMessage;ImportJavax.mail.internet.MimeMultipart;/*** Send mail **/ Public classMail {PrivateMimeMessage mimemsg; PrivateSession session; PrivateProperties props; PrivateString username; PrivateString password; PrivateMultipart MP;  PublicMail (String smtp) {setsmtphost (SMTP);    Createmimemessage (); }         Public voidsetsmtphost (String hostName) {System.out.println ("Set System Properties: mail.smtp.host=" +hostName); if(props==NULL) {Props=system.getproperties (); } props.put ("Mail.smtp.host", HostName); }         Public BooleanCreatemimemessage () {Try{System.out.println ("Ready to get mail Session Object!" "); Session= Session.getdefaultinstance (Props,NULL); }Catch(Exception e) {System.out.println ("An error occurred while getting mail session Object!" "+e); return false; } System.out.println ("Ready to create a MIME mail Object!" "); Try{mimemsg=NewMimeMessage (session); MP=NewMimemultipart (); return true; }Catch(Exception e) {System.out.println ("Failed to create MIME message Object!" "+e); return false; }    }    /*** Set whether SMTP requires authentication*/       Public voidSetneedauth (Booleanneed) {System.out.println ("Set SMTP authentication: Mail.smtp.auth =" +need); if(Props = =NULL) props =system.getproperties (); if(need) {Props.put ("Mail.smtp.auth", "true"); }Else{props.put ("Mail.smtp.auth", "false"); }        }         Public voidSetnamepass (String name,string pass) {username=name; Password=Pass; }         /*** Set Message subject*/       Public BooleanSetsubject (String mailsubject) {System.out.println ("Set the message subject!" "); Try{mimemsg.setsubject (mailsubject); return true; }            Catch(Exception e) {System.err.println ("There was an error setting the message subject!" "); return false; }        }              /*** Set message body*/         Public Booleansetbody (String mailbody) {Try{bodypart bp=NewMimeBodyPart (); Bp.setcontent ("" +mailbody, "TEXT/HTML;CHARSET=GBK");                           Mp.addbodypart (BP); return true; } Catch(Exception e) {System.err.println ("An error occurred while setting the message body!" "+e); return false; }        }                   /*** Set Sender*/         Public BooleanSetfrom (String from) {System.out.println ("Set the sender!" "); Try{Mimemsg.setfrom (NewInternetAddress (from));//Set Sender            return true; } Catch(Exception e) {return false; }        }        /*** Set up the recipient.*/         Public BooleanSetto (String to) {if(To = =NULL)return false; System.out.println ("Set up the recipient!" he said. "); Try{mimemsg.setrecipients (Message.recipienttype.to,internetaddress.parse (to)); return true; } Catch(Exception e) {return false; }          }               /*** Set cc person*/         Public BooleanSetcopyto (String copyto) {if(CopyTo = =NULL)return false; Try{mimemsg.setrecipients (Message.RecipientType.CC, (address[]) Internetaddress.parse (CopyTo)); return true; }            Catch(Exception e) {return false; } }               /*** Send mail*/         Public Booleansendout () {Try{mimemsg.setcontent (MP);                Mimemsg.savechanges (); System.out.println ("Sending mail ...."); Session mailsession= Session.getinstance (Props,NULL); Transport Transport= Mailsession.gettransport ("SMTP"); Transport.connect (String) props.get ("Mail.smtp.host"), Username,password);                             Transport.sendmessage (Mimemsg,mimemsg.getrecipients (Message.RecipientType.TO)); System.out.println ("Send mail success!" ");                               Transport.close (); return true; } Catch(Exception e) {System.err.println ("Mail sent failed!" "+e); return false; }        }               /*** Call sendout method to complete mail sending*/       Public Static BooleanSENDANDCC (String smtp,string from,string to,string copyto,string subject,string content,string username,String Password) {Mail Themail=NewMail (SMTP); Themail.setneedauth (true);//need to verify                   if(!themail.setsubject (subject))return false; if(!themail.setbody (content))return false; if(!themail.setto (To))return false; if(!themail.setcopyto (CopyTo))return false; if(!themail.setfrom (from))return false;                   Themail.setnamepass (Username,password); if(!themail.sendout ())return false; return true; }   }

JAVA EE (brief)