JNDI

最新推荐文章于 2025-08-08 22:01:10 发布

daijope

最新推荐文章于 2025-08-08 22:01:10 发布

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文章标签： javamail session string java server tomcat

本文链接：https://blog.youkuaiyun.com/daijope/article/details/6567130

本文介绍如何在Tomcat环境下配置JNDI以使用JavaMail发送邮件，包括配置资源需求、设置Tomcat资源工厂及安装JavaMail库等步骤。

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package com.dai.mail; import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import javax.mail.Message; import javax.mail.MessagingException; import javax.mail.Session; import javax.mail.Transport; import javax.mail.internet.AddressException; 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; public class SendMailServlet extends HttpServlet { /** * Constructor of the object. */ public SendMailServlet() { super(); } /** * Destruction of the servlet. <br> */ public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String smtpServer = "smtp.sina.com.cn";//邮件服务器主机名 String protocol = "smtp";//邮件传输协议 String username = "15829004147@sina.cn"; String password = "xxx"; String from = "15829004147@sina.cn"; String to = "243047007@qq.com"; String subject = "love"; String body = "I love you!"; //获取Session对象 Context initCtx; try { initCtx = new InitialContext(); Context envCtx = (Context)initCtx.lookup("java:comp/env"); Session session = (Session) envCtx.lookup("mail/Session"); MimeMessage msg = new MimeMessage(session); msg.setFrom(new InternetAddress(from)); msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to)); msg.setSentDate(new Date()); msg.setSubject(subject); msg.setText(body); msg.saveChanges(); Transport transport = session.getTransport(); transport.connect(smtpServer, username, password); transport.sendMessage(msg, msg.getRecipients(Message.RecipientType.TO)); transport.close(); response.setContentType("text/html;charset = GBK"); PrintWriter out = response.getWriter(); out.println("your mail has already sended"); System.out.println("ok"); } catch (NamingException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (AddressException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (MessagingException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * Initialization of the servlet. <br> * * @throws ServletException if an error occurs */ public void init() throws ServletException { // Put your code here } }

读文档学习tomcat JNDI的配置：

JNDI：java Naming and Directory Interface(java命名与目录接口)，它为java应用程序提供命名和目录访问服务的API。

JNDI中的Naming，就是将Java对象一某个名称的形式绑定到一个容器环境中，以后调用容器环境的查找方法又可以查找出某个名称所绑定的Java对象。

打开：D:/apache-tomcat-7.0.6/webapps/docs/jndi-resources-howto.html

下面是一个配置JavaMail sessions的例子:

0. Introduction

在许多的web应用中，发邮件使我们系统必须的功能，JavaMail给我们提供了简单的已经封转好了的API，但是客服端发送邮件，它就必须知道很多的环境配置信息细节。

tomcat有一个标准的resource factory，它可以帮我们传创建java.mail.session(这个类保存环境配置信息)的实例，resource factory会帮助我们配置好连接smtp服务器的各种细节信息。

好处：

In this way, the application is totally insulated from changes in the email server configuration environment - it simply asks for, and receives, a preconfigured session whenever needed.

百度文库：

包含了大量的命名和目录服务，使用通用接口来访问不同种类的服务；

可以同时连接到多个命名或目录服务上；　　

建立起逻辑关联，允许把名称同Java对象或资源关联起来，而不必知道对象或资源的物理ID。　　

JNDI程序包：　　

javax.naming ：命名操作；　　

javax.naming.directory ：目录操作；　　

javax.naming.event ：在命名目录服务器中请求事件通知；　　

javax.naming.ldap ：提供LDAP支持；　　

javax.naming.spi ：允许动态插入不同实现。　　

利用JNDI的命名与服务功能来满足企业级API对命名与服务的访问，诸如EJB、JMS、JDBC 2.0以及IIOP上的RMI通过JNDI来使用CORBA的命名服务。

1. Declare Your Resource Requirements

要完成JNDI的配置就要修改/WEB-INF/web.xml

一个典型的实例如下：

<resource-ref>

  <description>

    Resource reference to a factory for javax.mail.Session

    instances that may be used for sending electronic mail

    messages, preconfigured to connect to the appropriate

    SMTP server.

  </description>

  <res-ref-name>

    mail/Session

  </res-ref-name>

  <res-type>

    javax.mail.Session

  </res-type>

  <res-auth>

    Container

  </res-auth>

</resource-ref>

程序中的调用的代码为：(o,文档中写的很详细啊)

Context initCtx = new InitialContext();

Context envCtx = (Context) initCtx.lookup("java:comp/env");//java:comp/env
 naming context that is the root of

    all provided resource factories. 

Session session = (Session) envCtx.lookup("mail/Session");



Message message = new MimeMessage(session);

message.setFrom(new InternetAddress(request.getParameter("from")));

InternetAddress to[] = new InternetAddress[1];

to[0] = new InternetAddress(request.getParameter("to"));

message.setRecipients(Message.RecipientType.TO, to);

message.setSubject(request.getParameter("subject"));

message.setContent(request.getParameter("content"), "text/plain");

Transport.send(message);

下面的代码可以帮助理解：



Attribute attr = directory.getAttributes(personName).get("email");

　　String email = (String)attr.get();

　　通过使用JNDI让客户使用对象的名称或属性来查找对象：

　　foxes = directory.search("o=Wiz,c=US", "sn=Fox", controls);

　　通过使用JNDI来查找诸如打印机、数据库这样的对象，查找打印机的例子：

　　Printer printer = (Printer)namespace.lookup(printerName);

　　printer.print(document);

3. Configure Tomcat's Resource Factory

可以在我们的工程目录META-INF目录下建context.xml,添加代码：

<Context ...>

  ...

  <Resource name="mail/Session" auth="Container"

            type="javax.mail.Session"

            mail.smtp.host="localhost"/>

  ...

</Context>