《pro Spring》学习笔记之使用Sprin+James邮件服务器发送可替换的HTML和纯文本邮件
所谓可替换的意思就是说，同时发送两个内容，一个是HTML的，一个是纯文本的，具体现实那个内容要依据用户邮件客户端的配置来定
当需要对MIME消息就行更多的控制，你可以建立一个MimeMessagePreparator回调借口的实例，并把它传入JavaMailSender.send()方法，替换掉MimeMessage
<?
xml version="1.0" encoding="UTF-8"
?>
<
beans
xmlns
="http://www.springframework.org/schema/beans"
xmlns:xsi
="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation
="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"
>
<
bean
id
="messageSender"
class
="ch15.SimpleChangeMail.MessageSender"
>
<
property
name
="sender"
>
<
ref
bean
="sender"
/>
</
property
>
</
bean
>
<
bean
id
="sender"
class
="org.springframework.mail.javamail.JavaMailSenderImpl"
>
<
property
name
="host"
>
<
value
>
king.cn
</
value
>
</
property
>
<
property
name
="username"
>
<
value
>
gaoxiang
</
value
>
</
property
>
<
property
name
="password"
>
<
value
>
gaoxiang
</
value
>
</
property
>
<
property
name
="javaMailProperties"
>
<
props
>
<
prop
key
="mail.smtp.auth"
>
true
</
prop
>
<
prop
key
="mail.smtp.timeout"
>
10000
</
prop
>
</
props
>
</
property
>
</
bean
>
<
bean
id
="messagePreparator"
class
="ch15.SimpleChangeMail.MessagePreparator"
>
<
property
name
="to"
>
<
value
>
[email protected]
</
value
>
</
property
>
<
property
name
="from"
>
<
value
>
[email protected]
</
value
>
</
property
>
<
property
name
="subject"
>
<
value
>
html/text mime mail
</
value
>
</
property
>
<
property
name
="htmlContent"
>
<
value
>
<![CDATA[
<html><head><body>this is a html mail</body></head></html>
]]>
</
value
>
</
property
>
<
property
name
="textContent"
>
<
value
>
this is a text mail
</
value
>
</
property
>
</
bean
>
</
beans
>
package
ch15.SimpleChangeMail;
import
org.springframework.mail.javamail.JavaMailSenderImpl;
public
class
MessageSender
...
{
protected JavaMailSenderImpl sender;
public void sendMessage(MessagePreparator msgP)...{ sender.send(msgP);
} public JavaMailSenderImpl getSender() ...{ return sender; } public void setSender(JavaMailSenderImpl sender) ...{ this.sender = sender; } 
}
package
ch15.SimpleChangeMail;
import
javax.mail.BodyPart;
import
javax.mail.Message;
import
javax.mail.internet.InternetAddress;
import
javax.mail.internet.MimeBodyPart;
import
javax.mail.internet.MimeMessage;
import
javax.mail.internet.MimeMultipart;
import
org.springframework.mail.javamail.MimeMessagePreparator;
public
class
MessagePreparator
implements
MimeMessagePreparator
...
{ private String to; private String from; private String htmlContent; private String textContent; private String subject; public String getHtmlContent() ...{ return htmlContent; } public void setHtmlContent(String htmlContent) ...{ this.htmlContent = htmlContent; } public String getTextContent() ...{ return textContent; } public void setTextContent(String textContent) ...{ this.textContent = textContent; } public String getSubject() ...{ return subject; } public void setSubject(String subject) ...{ this.subject = subject; } public String getTo() ...{ return to; } public void setTo(String to) ...{ this.to = to; } public String getFrom() ...{ return from; } public void setFrom(String from) ...{ this.from = from; } public void prepare(MimeMessage msg) throws Exception ...{ //设置邮件信息 msg.addFrom(InternetAddress.parse(from)); msg.addRecipients(Message.RecipientType.TO, InternetAddress.parse(to)); msg.setSubject(subject); //创建multipart/alternative的包装器 MimeMultipart mimeMultipart=new MimeMultipart(); msg.setContent(mimeMultipart); //创建text的邮件体 BodyPart plainText=new MimeBodyPart(); plainText.setText(textContent); mimeMultipart.addBodyPart(plainText); //创建html的邮件体 BodyPart htmlText=new MimeBodyPart(); htmlText.setContent(htmlContent,"text/html"); mimeMultipart.addBodyPart(htmlText); } }
这里,prepare方法先设置发件人和收件人，还有主题，注意在设置发件人和收件人地址，我们必须使用InternetAddres.parse()的方法从一个String里建立一个InternetAddress实例，这是MimeMessageHelper方法隐藏的细节之一，一般总是使用MimeMessageHelper来配置消息属性，甚至是直接封装消息的时候
接下来，我们建立一个MimeMultipart实例，一个保存分段消息的封装类，我们指定MIME类型为Multipart/alternative，说明这里包含同一数据的可选格式，这个MimeMultipart实例被MimeMessage.setContent()方法指定为MimeMessage实例的正文
然后，我们创建两个MimeBodyPart，一个针对纯文本，一个针对html,前者会设置格式为Text/plain,后者再调用setContext方法时候，加一个参数"text/html",作为结果，他们都被被加入MimeMessage里，其中添加的顺序最为重要，应该把最希望显示的消息格式最后添加
这个代码结果是构造一个MimeMessage实例它顶层的Mime类型是multipart/alternative,包含两个消息，一个是text/plain,另一个是text/html
测试代码：
package
ch15.SimpleChangeMail;
import
java.io.File;
import
org.springframework.context.ApplicationContext;
import
org.springframework.context.support.ClassPathXmlApplicationContext;
public
class
SimpleChangeTest
...
{ public static void main(String[] args) throws Exception ...{ ApplicationContext context = new ClassPathXmlApplicationContext( "ch15/SimpleChangeMail/applicationContext.xml"); MessagePreparator messagePreparator = (MessagePreparator) context.getBean("messagePreparator"); MessageSender messageSender=(MessageSender)context.getBean("messageSender"); for (int i = 0; i < 10; i++) ...{ messageSender.sendMessage(messagePreparator); System.out.println("成功"); Thread.sleep(2000); //发送后延时2秒钟 } }}
发送成功后，客户端可以分别用html和纯文本方式查看邮件，可以看到不同的内容