发送电子邮件（Sending Email）
本章介绍如何使用Struts 2应用程序发送电子邮件。
在本练习中，您需要从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，然后继续执行创建操作，查看和配置的标准步骤文件。
Create Action
下一步是创建一个负责发送电子邮件的Action方法。 让我们创建一个名为Emailer.java的新类， Emailer.java包含以下内容。
package cn.xnip.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 - 上述帐户的密码
To - 谁发送电子邮件给？
Subject - 电子邮件的Subject
正文 - 实际的电子邮件消息
我们没有考虑对上述字段进行任何验证，验证将在下一章中添加。 现在让我们看一下execute（）方法。 execute（）方法使用javax Mail库使用提供的参数发送电子邮件。 如果邮件发送成功，则操作返回SUCCESS，否则返回ERROR。
创建主页面
让我们编写主页JSP文件index.jsp ，它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 (Create Views)
我们将使用JSP文件success.jsp ，它将在case操作返回SUCCESS时调用，但是如果从操作返回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>
error.jsp从操作返回ERROR，则以下将是视图文件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 (Configuration Files)
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 = "cn.xnip.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目录中部署此WAR。 最后，启动Tomcat服务器并尝试访问URL http://localhost:8080/HelloWorldStruts2/index.jsp 。 这将产生以下屏幕 -
输入所需信息，然后单击Send Email按钮。 如果一切顺利，那么您应该看到以下页面。
