【Mail】Tomcat提供JNDI方式支持JavaMail（三）

流程介绍　　

　　Tomcat提供了JavaMail的支持，是通过JNDI的方式实现的，具体流程是：

　　Tomcat启动的时候，自身产生一个Session对象，放在JNDI容器中给其他项目调用，其他项目只要通过JNDI API就能获取JNDI中的对象，并在项目中使用。

　　

使用步骤

1. 配置JNDI资源：新建一个javaweb的maven项目，并在webapp/META-INF中新建一个文件context.xml。
   
   
   context.xml文件内容如下：
   

   <Context>
     <Resource name="mail/Session" auth="Container"
               type="javax.mail.Session"
               mail.smtp.host="smtp.163.com" mail.smtp.auth="true"
               mail.transport.protocol="smtp"
               />
   </Context>

2. 添加javamail到tomcat的lib目录：Tomcat要新建session对象，那么tomcat就需要引入mail.jar包
   
3. 在java程序中通过JNDI API获取mail的session对象：写一个类MailServlet.java，去获取session对象。
   
   • MailServlet.java
     

     package com.hd.javamail.servlet;
     
     import java.io.IOException;
     
     import javax.mail.Address;
     import javax.mail.Message;
     import javax.mail.MessagingException;
     import javax.mail.Session;
     import javax.mail.Transport;
     import javax.mail.internet.InternetAddress;
     import javax.mail.internet.MimeMessage;
     import javax.naming.Context;
     import javax.naming.InitialContext;
     import javax.naming.NamingException;
     import javax.servlet.ServletException;
     import javax.servlet.http.HttpServlet;
     import javax.servlet.http.HttpServletRequest;
     import javax.servlet.http.HttpServletResponse;
     
     
     /**
      * Servlet implementation class MailServlet
      */
     public class MailServlet extends HttpServlet {
         private static final long serialVersionUID = 1L;
     
         /**
          * Default constructor. 
          */
         public MailServlet() {
             // TODO Auto-generated constructor stub
         }
     
         /**
          * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
          */
         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
             doPost(request, response);
         }
     
         /**
          * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
          */
         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     
             try {
                 //从tomcat中获取JNDI容器
                 Context initCtx = new InitialContext();
                 Context envCtx = (Context) initCtx.lookup("java:comp/env");
                 //JNDI中获取Mail的Session对象
                 Session session = (Session) envCtx.lookup("mail/Session");
                 
                 //新建一个邮件
                 Message message = new MimeMessage(session);
                 //设置发件人
                 message.setFrom(new InternetAddress("xxxx@163.com"));
                 //设置多个收件人
                 message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("123456@qq.com"));
                 //设置主题
                 message.setSubject("ha");
                 //设置文本
                 message.setText("test");
                 
                 //邮件传送对象
                 Transport transport = session.getTransport();
                 //设置，邮件服务器地址、用户名、密码
                 transport.connect("smtp.163.com", "xxxx@163.com", "xxxxxx");
                 //发送邮件（邮件，地址）
                 transport.sendMessage(message,  new Address[] {new InternetAddress("123456@qq.com")} );
                 //关闭连接
                 transport.close();
                 
                 response.getWriter().print("ok!");
                 
             } catch (MessagingException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             } catch (NamingException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
     
     }

   • web.xml中配置MailServlet
     

     <!DOCTYPE web-app PUBLIC
      "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
      "http://java.sun.com/dtd/web-app_2_3.dtd" >
     
     <web-app>
         <display-name>test-javamail</display-name>
         <servlet>
             <servlet-name>MailServlet</servlet-name>
             <display-name>MailServlet</display-name>
             <description></description>
             <servlet-class>com.hd.javamail.servlet.MailServlet</servlet-class>
         </servlet>
         <servlet-mapping>
             <servlet-name>MailServlet</servlet-name>
             <url-pattern>/MailServlet</url-pattern>
         </servlet-mapping>
         
     </web-app>

   • 注意pom文件中mail.jar的引用，只需在编译的时候使用，运行的时候使用前面tomcat／lib目录下的mail.jar包。所以需要如下配置，否则会出错。
     

     <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
         <modelVersion>4.0.0</modelVersion>
         <groupId>com.hd</groupId>
         <artifactId>test-javamail</artifactId>
         <packaging>war</packaging>
         <version>0.0.1-SNAPSHOT</version>
         <name>test-javamail Maven Webapp</name>
         <url>http://maven.apache.org</url>
         <dependencies>
         
             <!-- javamail -->
             <dependency>
                 <groupId>javax.mail</groupId>
                 <artifactId>mail</artifactId>
                 <version>1.4.7</version>
                 <scope>provided</scope><!-- 仅编译的时候使用，运行是由tomcat提供 -->
             </dependency>
             
             <dependency>
                 <groupId>javax.servlet</groupId>
                 <artifactId>javax.servlet-api</artifactId>
                 <version>3.0.1</version>
                 <scope>provided</scope>
             </dependency>
             <dependency>
                 <groupId>javax.servlet.jsp</groupId>
                 <artifactId>jsp-api</artifactId>
                 <version>2.2</version>
                 <scope>provided</scope>
             </dependency>
     
             <dependency>
                 <groupId>junit</groupId>
                 <artifactId>junit</artifactId>
                 <version>3.8.1</version>
                 <scope>test</scope>
             </dependency>
         </dependencies>
         <build>
             <finalName>test-javamail</finalName>
         </build>
     </project>

测试运行

　　在浏览器中访问MailServlet，地址：http://ip:端口/test-javamail/MailServlet