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  Struts - 发送电子邮件

  • 简述

    本章解释了如何使用 Struts 2 应用程序发送电子邮件。
    对于本练习，您需要从JavaMail API 1.4.4下载并安装 mail.jar ，并将mail.jar WEB-INF\lib 文件夹中的文件，然后继续遵循创建操作、视图和配置文件的标准步骤。

  • 创建动作

    下一步是创建一个处理发送电子邮件的 Action 方法。让我们创建一个名为的新类Emailer.java 有以下内容。 
    
package com.jc2182.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性。这些属性是 -
    • From− 发件人的电子邮件地址。由于我们使用的是 Google 的 SMTP，因此我们需要一个有效的 gtalk id
    • Password − 上述账户的密码
    • To − 向谁发送电子邮件？
    • Subject - 电子邮件的主题
    • Body − 实际的电子邮件信息
    我们没有考虑对上述字段进行任何验证，将在下一章中添加验证。现在让我们看看 execute() 方法。execute() 方法使用 javax Mail 库通过提供的参数发送电子邮件。如果邮件发送成功，action 返回 SUCCESS，否则返回 ERROR。

  • 创建主页

    让我们编写主页面 JSP 文件 index.jsp，将用于收集上述电子邮件相关信息 - 
    
<%@ 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

    我们将使用 JSP 文件 success.jsp 在 action 返回 SUCCESS 的情况下将调用它，但如果从 action 返回 ERROR，我们将有另一个视图文件。 
    
<%@ 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>
    以下将是视图文件 error.jsp 如果从操作返回错误。 
    
<%@ 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

    现在让我们使用 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 = "com.jc2182.struts2.Emailer"
         method = "execute">
         <result name = "success">/success.jsp</result>
         <result name = "error">/error.jsp</result>
      </action>
   </package>
</struts>
    以下是内容 web.xml 文件 - 
    
<?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，右键单击项目名称并单击 Export > WAR File创建一个战争文件。然后将此 WAR 部署到 Tomcat 的 webapps 目录中。最后，启动Tomcat服务器并尝试访问URLhttp://localhost:8080/HelloWorldStruts2/index.jsp. 这将产生以下屏幕 -
    电子邮件用户输入
    输入所需信息并单击 Send Email按钮。如果一切顺利，那么您应该会看到以下页面。
    电子邮件成功
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