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：
   

   1 <Context>
   2   <Resource name="mail/Session" auth="Container"
   3             type="javax.mail.Session"
   4             mail.smtp.host="smtp.163.com" mail.smtp.auth="true"
   5             mail.transport.protocol="smtp"
   6             />
   7 </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
     

      1 package com.hd.javamail.servlet;
      2 
      3 import java.io.IOException;
      4 
      5 import javax.mail.Address;
      6 import javax.mail.Message;
      7 import javax.mail.MessagingException;
      8 import javax.mail.Session;
      9 import javax.mail.Transport;
     10 import javax.mail.internet.InternetAddress;
     11 import javax.mail.internet.MimeMessage;
     12 import javax.naming.Context;
     13 import javax.naming.InitialContext;
     14 import javax.naming.NamingException;
     15 import javax.servlet.ServletException;
     16 import javax.servlet.http.HttpServlet;
     17 import javax.servlet.http.HttpServletRequest;
     18 import javax.servlet.http.HttpServletResponse;
     19 
     20 
     21 /**
     22  * Servlet implementation class MailServlet
     23  */
     24 public class MailServlet extends HttpServlet {
     25     private static final long serialVersionUID = 1L;
     26 
     27     /**
     28      * Default constructor. 
     29      */
     30     public MailServlet() {
     31         // TODO Auto-generated constructor stub
     32     }
     33 
     34     /**
     35      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     36      */
     37     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     38         doPost(request, response);
     39     }
     40 
     41     /**
     42      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     43      */
     44     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     45 
     46         try {
     47             //从tomcat中获取JNDI容器
     48             Context initCtx = new InitialContext();
     49             Context envCtx = (Context) initCtx.lookup("java:comp/env");
     50             //JNDI中获取Mail的Session对象
     51             Session session = (Session) envCtx.lookup("mail/Session");
     52             
     53             //新建一个邮件
     54             Message message = new MimeMessage(session);
     55             //设置发件人
     56             message.setFrom(new InternetAddress("xxxx@163.com"));
     57             //设置多个收件人
     58             message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("123456@qq.com"));
     59             //设置主题
     60             message.setSubject("ha");
     61             //设置文本
     62             message.setText("test");
     63             
     64             //邮件传送对象
     65             Transport transport = session.getTransport();
     66             //设置，邮件服务器地址、用户名、密码
     67             transport.connect("smtp.163.com", "xxxx@163.com", "xxxxxx");
     68             //发送邮件（邮件，地址）
     69             transport.sendMessage(message,  new Address[] {new InternetAddress("123456@qq.com")} );
     70             //关闭连接
     71             transport.close();
     72             
     73             response.getWriter().print("ok!");
     74             
     75         } catch (MessagingException e) {
     76             // TODO Auto-generated catch block
     77             e.printStackTrace();
     78         } catch (NamingException e) {
     79             // TODO Auto-generated catch block
     80             e.printStackTrace();
     81         }
     82     }
     83 
     84 }

      

   • web.xml中配置MailServlet
     

      1 <!DOCTYPE web-app PUBLIC
      2  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
      3  "http://java.sun.com/dtd/web-app_2_3.dtd" >
      4 
      5 <web-app>
      6     <display-name>test-javamail</display-name>
      7     <servlet>
      8         <servlet-name>MailServlet</servlet-name>
      9         <display-name>MailServlet</display-name>
     10         <description></description>
     11         <servlet-class>com.hd.javamail.servlet.MailServlet</servlet-class>
     12     </servlet>
     13     <servlet-mapping>
     14         <servlet-name>MailServlet</servlet-name>
     15         <url-pattern>/MailServlet</url-pattern>
     16     </servlet-mapping>
     17     
     18 </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。
     

      1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      2     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
      3     <modelVersion>4.0.0</modelVersion>
      4     <groupId>com.hd</groupId>
      5     <artifactId>test-javamail</artifactId>
      6     <packaging>war</packaging>
      7     <version>0.0.1-SNAPSHOT</version>
      8     <name>test-javamail Maven Webapp</name>
      9     <url>http://maven.apache.org</url>
     10     <dependencies>
     11     
     12         <!-- javamail -->
     13         <dependency>
     14             <groupId>javax.mail</groupId>
     15             <artifactId>mail</artifactId>
     16             <version>1.4.7</version>
     17             <scope>provided</scope><!-- 仅编译的时候使用，运行是由tomcat提供 -->
     18         </dependency>
     19         
     20         <dependency>
     21             <groupId>javax.servlet</groupId>
     22             <artifactId>javax.servlet-api</artifactId>
     23             <version>3.0.1</version>
     24             <scope>provided</scope>
     25         </dependency>
     26         <dependency>
     27             <groupId>javax.servlet.jsp</groupId>
     28             <artifactId>jsp-api</artifactId>
     29             <version>2.2</version>
     30             <scope>provided</scope>
     31         </dependency>
     32 
     33         <dependency>
     34             <groupId>junit</groupId>
     35             <artifactId>junit</artifactId>
     36             <version>3.8.1</version>
     37             <scope>test</scope>
     38         </dependency>
     39     </dependencies>
     40     <build>
     41         <finalName>test-javamail</finalName>
     42     </build>
     43 </project>

      

测试运行

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

【Mail】Tomcat提供JNDI方式支持JavaMail（三）