【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