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本章内容将教你如何使用Struts2 应用程序发送电子邮件。学习前,你需要从JavaMail API 1.4.4下载并安装mail.jar,并将mail.jar文件放在WEB-INF\lib文件夹中,然后继续按照以下标准步骤创建action,视图和配置文件。

创建Action

首先是创建一个Action方法来处理电子邮件发送。让我们创建一个包含以下内容的名为Emailer.java的新类:

package cn.Vue5教程.struts2;

import java.util.Properties;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

import com.opensymphony.xwork2.ActionSupport;

public class Emailer extends ActionSupport {

   private String from;
   private String password;
   private String to;
   private String subject;
   private String body;

   static Properties properties = new Properties();
   static
   {
      properties.put("mail.smtp.host", "smtp.gmail.com");
      properties.put("mail.smtp.socketFactory.port", "465");
      properties.put("mail.smtp.socketFactory.class",
                     "javax.net.ssl.SSLSocketFactory");
      properties.put("mail.smtp.auth", "true");
      properties.put("mail.smtp.port", "465");
   }

   public String execute() 
   {
      String ret = SUCCESS;
      try
      {
         Session session = Session.getDefaultInstance(properties,  
            new javax.mail.Authenticator() {
            protected PasswordAuthentication 
            getPasswordAuthentication() {
            return new 
            PasswordAuthentication(from, password);
            }});

         Message message = new MimeMessage(session);
         message.setFrom(new InternetAddress(from));
         message.setRecipients(Message.RecipientType.TO, 
            InternetAddress.parse(to));
         message.setSubject(subject);
         message.setText(body);
         Transport.send(message);
      }
      catch(Exception e)
      {
         ret = ERROR;
         e.printStackTrace();
      }
      return ret;
   }

   public String getFrom() {
      return from;
   }

   public void setFrom(String from) {
      this.from = from;
   }

   public String getPassword() {
      return password;
   }

   public void setPassword(String password) {
      this.password = password;
   }

   public String getTo() {
      return to;
   }

   public void setTo(String to) {
      this.to = to;
   }

   public String getSubject() {
      return subject;
   }

   public void setSubject(String subject) {
      this.subject = subject;
   }

   public String getBody() {
      return body;
   }

   public void setBody(String body) {
      this.body = body;
   }

   public static Properties getProperties() {
      return properties;
   }

   public static void setProperties(Properties properties) {
      Emailer.properties = properties;
   }
}

如上面的源代码所示,Emailer.java具有与下面给出的email.jsp页面中的表单属性相对应的属,这些属性分别是:

  • from - 发件人的电子邮件地址。由于我们使用Google的SMTP,因此我们需要有效的gtalk ID。

  • password - 上述帐户的密码

  • to - 发送电子邮件给谁?

  • Subject - 电子邮件的主题

  • body - 实际的电子邮件内容

我们没有考虑对上述字段的任何验证,验证将在下一章添加。让我们看看execute()方法, execute()方法使用javax Mail库提供的参数发送电子邮件。如果邮件成功发送,action返回SUCCESS,否则返回ERROR。

创建主页

现行编写主页的JSP文件index.jsp,这将用于收集上面提到的电子邮件相关信息:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
   pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Email Form</title>
</head>
<body>
   <em>The form below uses Google's SMTP server. 
   So you need to enter a gmail username and password
   </em>
   <form action="emailer" method="post">
   <label for="from">From</label><br/>
   <input type="text" name="from"/><br/>
   <label for="password">Password</label><br/>
   <input type="password" name="password"/><br/>
   <label for="to">To</label><br/>
   <input type="text" name="to"/><br/>
   <label for="subject">Subject</label><br/>
   <input type="text" name="subject"/><br/>
   <label for="body">Body</label><br/>
   <input type="text" name="body"/><br/>
   <input type="submit" value="Send Email"/>
   </form>
</body>
</html>

创建视图

现在创建success.jsp文件,这在action返回SUCCESS结果的情况下会被调用,但如果从action返回ERROR结果,我们将用另一个视图文件。

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Email Success</title>
</head>
<body>
   Your email to <s:property value="to"/> was sent successfully.
</body>
</html>

以下将是在action返回ERROR的情况下调用的视图文件error.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Email Error</title>
</head>
<body>
   There is a problem sending your email to <s:property value="to"/>.
</body>
</html>

配置文件

最后,让我们使用struts.xml配置文件将所有内容放在一起,如下所示:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
   "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
   "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

   <constant name="struts.devMode" value="true" />
   <package name="helloworld" extends="struts-default">

      <action name="emailer" 
         class="cn.Vue5教程.struts2.Emailer"
         method="execute">
         <result name="success">/success.jsp</result>
         <result name="error">/error.jsp</result>
      </action>

   </package>

</struts>

以下是web.xml文件的内容:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee" 
   xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
   http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
   id="WebApp_ID" version="3.0">
   
   <display-name>Struts 2</display-name>
   <welcome-file-list>
      <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>

   <filter>
      <filter-name>struts2</filter-name>
      <filter-class>
         org.apache.struts2.dispatcher.FilterDispatcher
      </filter-class>
   </filter>

   <filter-mapping>
      <filter-name>struts2</filter-name>
      <url-pattern>/*</url-pattern>
   </filter-mapping>
</web-app>

现在,右键单击项目名称,然后单击“Export”> “WAR File”以创建WAR文件。然后在Tomcat的webapps目录中部署WAR文件。最后,启动Tomcat服务器并尝试访问URL http://localhost:8080/HelloWorldStruts2/index.jsp,将显示以下界面:

电子邮件用户输入

输入所需的信息,然后单击Send Email按钮。如果一切正常,那么你可以看到以下页面:

电子邮件成功