Spring Boot發送電子郵件

通過使用Spring Boot RESTful Web服務,可以發送包含Gmail傳輸層安全性的電子郵件。 在本章中,詳細瞭解如何使用此功能。

首先,需要在構建配置文件中添加Spring Boot Starter Mail依賴項。

Maven用戶可以將以下依賴項添加到pom.xml 文件中。

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

Gradle用戶可以在build.gradle 文件中添加以下依賴項。

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

主 Spring Boot 應用程序類文件的代碼如下 -

package com.yiibai.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);
   }
}

可以編寫一個簡單的Rest API,以便在Rest Controller類文件中發送到電子郵件,如圖所示。

package com.yiibai.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";
   }   
}

編寫一個方法來發送帶有附件的電子郵件。 定義mail.smtp屬性並使用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("[email protected]", "<your password>");
      }
   });
   Message msg = new MimeMessage(session);
   msg.setFrom(new InternetAddress("[email protected]", false));

   msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse("[email protected]"));
   msg.setSubject("Spring Boot Yiibai email");
   msg.setContent("Spring Boot Yiibai email", "text/html");
   msg.setSentDate(new Date());

   MimeBodyPart messageBodyPart = new MimeBodyPart();
   messageBodyPart.setContent("Spring Boot Yiibai 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);   
}

現在,從Rest API調用上面的sendmail()方法,如圖所示 -

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

注意 - 在發送電子郵件之前,請在Gmail帳戶設置中啓用不太安全的應用。

完整的構建配置文件如下所示。

Maven構建文件 - 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.yiibai</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構建文件 - 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.yiibai'
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')
}

現在,可以創建一個可執行的JAR文件,並使用下面顯示的Maven或Gradle命令運行Spring Boot應用程序 -

對於Maven,可以使用如下所示的命令 -

mvn clean install

在「BUILD SUCCESS」之後,可以在target目錄下找到JAR文件。

對於Gradle,可以使用如下所示的命令 -

gradle clean build

在「BUILD SUCCESSFUL」之後,可以在build/libs目錄下找到JAR文件。

現在,使用下面給出的命令運行JAR文件 -

java –jar <JARFILE>

看到應用程序已在Tomcat端口8080上啓動。

現在,從Web瀏覽器中打開以下URL => http://localhost:8080/sendemail

Spring Boot發送電子郵件

發送成功後,開登錄郵件賬戶將收到一封電子郵件。