Spring Boot - 发送电子邮件

通过使用Spring Boot RESTful Web服务，您可以发送包含Gmail传输层安全性的电子邮件。在本章中，让我们详细了解如何使用此功能。

首先，我们需要在构建配置文件中添加Spring Boot Starter Mail依赖项。

Maven用户可以将以下依赖项添加到pom.xml文件中。

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

Gradle用户可以在build.gradle文件中添加以下依赖项。

compile('org.springframework.boot:spring-boot-starter-mail')

主要的Spring Boot应用程序类文件的代码如下

package com.codingdict.emailapp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class EmailappApplication {
   public static void main(String[] args) {
      SpringApplication.run(EmailappApplication.class, args);
   }
}

您可以编写一个简单的Rest API，以便在Rest Controller类文件中发送到电子邮件，如图所示。

package com.codingdict.emailapp;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class EmailController {
   @RequestMapping(value = "/sendemail")
   public String sendEmail() {
      return "Email sent successfully";
   }   
}

您可以编写一个方法来发送带有附件的电子邮件。定义mail.smtp属性并使用PasswordAuthentication。

private void sendmail() throws AddressException, MessagingException, IOException {
   Properties props = new Properties();
   props.put("mail.smtp.auth", "true");
   props.put("mail.smtp.starttls.enable", "true");
   props.put("mail.smtp.host", "smtp.gmail.com");
   props.put("mail.smtp.port", "587");

   Session session = Session.getInstance(props, new javax.mail.Authenticator() {
      protected PasswordAuthentication getPasswordAuthentication() {
         return new PasswordAuthentication("codingdict@gmail.com", "<your password>");
      }
   });
   Message msg = new MimeMessage(session);
   msg.setFrom(new InternetAddress("codingdict@gmail.com", false));

   msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse("codingdict@gmail.com"));
   msg.setSubject("Tutorials point email");
   msg.setContent("Tutorials point email", "text/html");
   msg.setSentDate(new Date());

   MimeBodyPart messageBodyPart = new MimeBodyPart();
   messageBodyPart.setContent("Tutorials point email", "text/html");

   Multipart multipart = new MimeMultipart();
   multipart.addBodyPart(messageBodyPart);
   MimeBodyPart attachPart = new MimeBodyPart();

   attachPart.attachFile("/var/tmp/image19.png");
   multipart.addBodyPart(attachPart);
   msg.setContent(multipart);
   Transport.send(msg);   
}

现在，从Rest API调用上面的sendmail()方法，如图所示

@RequestMapping(value = "/sendemail")
public String sendEmail() throws AddressException, MessagingException, IOException {
   sendmail();
   return "Email sent successfully";   
}

注意 - 在发送电子邮件之前，请在Gmail帐户设置中启用不太安全的应用。

完整的构建配置文件如下所示。

Maven - pom.xml

<?xml version = "1.0" encoding = "UTF-8"?>
<project xmlns = "http://maven.apache.org/POM/4.0.0"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0
   http://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>
   <groupId>com.codingdict</groupId>
   <artifactId>emailapp</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>
   <name>emailapp</name>
   <description>Demo project for Spring Boot</description>

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.9.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
   </properties>

   <dependencies>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>

      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-mail</artifactId>
      </dependency>

      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
      </dependency>

      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>

</project>

Gradle - build.gradle

buildscript {
   ext {
      springBootVersion = '1.5.9.RELEASE'
   }
   repositories {
      mavenCentral()
   }
   dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

group = 'com.codingdict'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8

repositories {
   mavenCentral()
}
dependencies {
   compile('org.springframework.boot:spring-boot-starter-web')
   compile('org.springframework.boot:spring-boot-starter-mail')
   testCompile('org.springframework.boot:spring-boot-starter-test')
}

现在，您可以创建一个可执行的JAR文件，并使用下面显示的Maven或Gradle命令运行Spring Boot应用程序

对于Maven，您可以使用如下所示的命令