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Ce document utilise Manuel du site Web PHP chinois Libérer
假设某个业务接口名为OrderManager
:
public interface OrderManager { void placeOrder(Order order); }
我们同时假设有一个用例:需要生成带有订单号的email信件, 并向客户发送该订单。
import org.springframework.mail.MailException; import org.springframework.mail.MailSender; import org.springframework.mail.SimpleMailMessage; public class SimpleOrderManager implements OrderManager { private MailSender mailSender; private SimpleMailMessage templateMessage; public void setMailSender(MailSender mailSender) { this.mailSender = mailSender; } public void setTemplateMessage(SimpleMailMessage templateMessage) { this.templateMessage = templateMessage; } public void placeOrder(Order order) { // Do the business calculations... // Call the collaborators to persist the order... // Create a thread safe "copy" of the template message and customize it SimpleMailMessage msg = new SimpleMailMessage(this.templateMessage); msg.setTo(order.getCustomer().getEmailAddress()); msg.setText( "Dear " + order.getCustomer().getFirstName() + order.getCustomer().getLastName() + ", thank you for placing order. Your order number is " + order.getOrderNumber()); try{ this.mailSender.send(msg); } catch(MailException ex) { // simply log it and go on... System.err.println(ex.getMessage()); } } }
上面的代码的bean定义应该是这样的:
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<property name="host" value="mail.mycompany.com"/>
</bean>
<!-- this is a template message that we can pre-load with default state -->
<bean id="templateMessage" class="org.springframework.mail.SimpleMailMessage">
<property name="from" value="customerservice@mycompany.com"/>
<property name="subject" value="Your order"/>
</bean>
<bean id="orderManager" class="com.mycompany.businessapp.support.SimpleOrderManager">
<property name="mailSender" ref="mailSender"/>
<property name="templateMessage" ref="templateMessage"/>
</bean>
下面是OrderManager
的另一种实现, 使用了MimeMessagePreparator
回调接口。
请注意在这个用例中,mailSender
属性是JavaMailSender
类型, 所以我们可以使用JavaMail的MimeMessage
类:
import javax.mail.Message; import javax.mail.MessagingException; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; import javax.mail.internet.MimeMessage; import org.springframework.mail.MailException; import org.springframework.mail.javamail.JavaMailSender; import org.springframework.mail.javamail.MimeMessagePreparator; public class SimpleOrderManager implements OrderManager { private JavaMailSender mailSender; public void setMailSender(JavaMailSender mailSender) { this.mailSender = mailSender; } public void placeOrder(final Order order) { // Do the business calculations... // Call the collaborators to persist the order... MimeMessagePreparator preparator = new MimeMessagePreparator() { public void prepare(MimeMessage mimeMessage) throws Exception { mimeMessage.setRecipient(Message.RecipientType.TO, new InternetAddress(order.getCustomer().getEmailAddress())); mimeMessage.setFrom(new InternetAddress("mail@mycompany.com")); mimeMessage.setText( "Dear " + order.getCustomer().getFirstName() + " " + order.getCustomer().getLastName() + ", thank you for placing order. Your order number is " + order.getOrderNumber()); } }; try { this.mailSender.send(preparator); } catch (MailException ex) { // simply log it and go on... System.err.println(ex.getMessage()); } } }
以上的邮件代码是一个横切关注点,能被完美地重构为自定义Spring AOP切面的候选者,这样它就可以在目标对象OrderManager
的一些合适的连接点(joinpoint)中被执行了。
Spring Framework的邮件支持直接提供两种MailSender
的实现。标准的JavaMail实现和基于Jason Hunter编写的MailMessage
类之上的实现,后者位于
com.oreilly.servlet
包中。请查阅相关Javadocs以获得进一步的资料。