SpringBoot入门建站全系列（十）邮件发送功能

朱雀 2022-10-02 13:55 188阅读 0赞

## SpringBoot入门建站全系列（十）邮件发送功能 ##

Spring Mail API都在org.springframework.mail及其子包org.springframework.mail.javamail中封装。

JavaMailSenderImpl: 邮件发送器，主要提供了邮件发送接口、透明创建Java Mail的MimeMessage、及邮件发送的配置(如:host/port/username/password…)。  
MimeMailMessage、MimeMessageHelper：对MimeMessage进行了封装。Spring还提供了一个回调接口MimeMessagePreparator, 用于准备JavaMail的MIME信件.

SpringBoot对Email做了封装：[https://docs.spring.io/spring-boot/docs/2.0.9.RELEASE/reference/htmlsingle/\#boot-features-email  
][https_docs.spring.io_spring-boot_docs_2.0.9.RELEASE_reference_htmlsingle_boot-features-email]

直接读取配置，然后我们的Service逻辑可以直接注入JavaMailSender进行邮件发送。

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### 一、配置 ###

本文假设你已经引入spring-boot-starter-web。已经是个SpringBoot项目了,如果不会搭建，可以打开这篇文章看一看[《SpringBoot入门建站全系列（一）项目建立》][SpringBoot 1]。

#### 1.1 Maven依赖 ####

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

配置fastjson是因为我写的示例中用到了，用不到的话就可以去掉。

#### 1.2 配置文件 ####

application.properties 中需要添加下面的配置：

spring.mail.host=smtp.qq.com
    spring.mail.username=916881512@qq.com
    spring.mail.password=xxxxx
    spring.mail.port=465
    spring.mail.properties.mail.smtp.auth=true
    spring.mail.properties.mail.smtp.starttls.enable=true
    spring.mail.properties.mail.smtp.ssl.enable=true
    spring.mail.properties.mail.smtp.starttls.required=true 
    
    mail.from=916881512@qq.com
    mail.fromName=Admin

这里，

*  spring.mail.properties是额外的配置信息。
 *  spring.mail.port这个很重要，我用的是465，是smtp的ssl端口，smtp一般是用25端口，但是很多云服务器把25端口禁用了，美其名曰安全。所以可以用465端口也发送邮件。如果想用25端口，后面的spring.mail.properties.\*去掉即可。
 *  mail.from和mail.fromName是业务逻辑需要的配置，不是SpringBoot自动装配的。
 *  其他配置文件都是见文知意了，不再说了。

SpringBoot官网配置文件说明：

# Email (MailProperties)
    spring.mail.default-encoding=UTF-8 # Default MimeMessage encoding.
    spring.mail.host= # SMTP server host. For instance, `smtp.example.com`.
    spring.mail.jndi-name= # Session JNDI name. When set, takes precedence over other Session settings.
    spring.mail.password= # Login password of the SMTP server.
    spring.mail.port= # SMTP server port.
    spring.mail.properties.*= # Additional JavaMail Session properties.
    spring.mail.protocol=smtp # Protocol used by the SMTP server.
    spring.mail.test-connection=false # Whether to test that the mail server is available on startup.
    spring.mail.username= # Login user of the SMTP server.

### 二、发送邮件业务逻辑 ###

发送邮件时，需要指明发送人邮箱和名称。

package com.cff.springbootwork.mail.service;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.List;
    
    import javax.mail.MessagingException;
    import javax.mail.internet.MimeMessage;
    import javax.mail.internet.MimeUtility;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.core.io.FileSystemResource;
    import org.springframework.mail.MailException;
    import org.springframework.mail.javamail.JavaMailSender;
    import org.springframework.mail.javamail.MimeMessageHelper;
    import org.springframework.stereotype.Service;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONArray;
    import com.alibaba.fastjson.JSONObject;
    import com.alibaba.fastjson.parser.Feature;
    import com.cff.springbootwork.mail.type.*;
    
    @Service
    public class MailService { 
    	private final Logger logger = LoggerFactory.getLogger(this.getClass());
    	static final String DELIM_STR = "{}";
    
    	@Autowired
    	private JavaMailSender javaMailSender;
    	
    	@Value("${mail.from}")
    	private String from;
    	
    	@Value("${mail.fromName}")
    	private String fromName;
    	
    	/** * 简单发送html内容 * * @param to * 指定收件人 * @param subject * 主题 * @param content * 内容 * @param isHtml * 是否是html */
    	public void sendSimpleMail(String to, String subject, String content, boolean isHtml) { 
    		MimeMessage message = javaMailSender.createMimeMessage();
    		try { 
    			MimeMessageHelper helper = new MimeMessageHelper(message, true);
    			helper.setFrom(from,fromName);
    			helper.setTo(to);
    			helper.setSubject(subject);
    			helper.setText(content, isHtml);
    			javaMailSender.send(message);
    			logger.info("html邮件发送成功");
    		} catch (MessagingException e) { 
    			logger.error("发送html邮件时发生异常！", e);
    		} catch (UnsupportedEncodingException e) { 
    			logger.error("发送html邮件时发生异常！", e);
    		}
    
    	}
    
    	/** * 简单发送内嵌文件方法 * * @param to * 指定收件人 * @param subject * 主题 * @param content * 内容 * @param rscPath * 资源路径（文件路径） * @param rscId * 资源标识 */
    	public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId) { 
    		MimeMessage message = javaMailSender.createMimeMessage();
    
    		try { 
    			MimeMessageHelper helper = new MimeMessageHelper(message, true);
    			helper.setFrom(from,fromName);
    			helper.setTo(to);
    			helper.setSubject(subject);
    			helper.setText(content, true);
    
    			FileSystemResource res = new FileSystemResource(new File(rscPath));
    			helper.addInline(rscId, res);
    
    			javaMailSender.send(message);
    			logger.info("嵌入静态资源的邮件已经发送。");
    		} catch (MessagingException e) { 
    			logger.error("发送嵌入静态资源的邮件时发生异常！", e);
    		} catch (UnsupportedEncodingException e) { 
    			logger.error("发送嵌入静态资源的邮件时发生异常！", e);
    		}
    	}
    
    	/** * 简单发送附件方法 * * @param to * 指定收件人 * @param subject * 主题 * @param content * 内容 * @param filePath * 附件地址，可传递多个 */
    	public void sendAttachmentsMail(String to, String subject, String content, String[] filePaths) { 
    		System.getProperties().setProperty("mail.mime.splitlongparameters", "false");
    
    		MimeMessage message = javaMailSender.createMimeMessage();
    		try { 
    			MimeMessageHelper helper = new MimeMessageHelper(message, true, "utf-8");
    			helper.setFrom(from,fromName);
    			helper.setTo(to);
    			helper.setSubject(subject);
    			helper.setText(content, true);
    
    			for (String filePath : filePaths) { 
    				FileSystemResource file = new FileSystemResource(new File(filePath));
    				String fileName = filePath.substring(filePath.lastIndexOf(File.separator) + 1);
    				helper.addAttachment(MimeUtility.encodeText(fileName), file);
    			}
    
    			javaMailSender.send(message);
    			logger.info("带附件的邮件已经发送。");
    		} catch (MessagingException e) { 
    			logger.error("发送带附件的邮件时发生异常！", e);
    		} catch (UnsupportedEncodingException e) { 
    			e.printStackTrace();
    		}
    	}
    
    	/** * 完整发送邮件方法，需要调用setMailMessage方法配置邮件 {@link #setMailMessage(MailMessage)} * <p>占位符使用{},内容中如果要使用{},就修改代码吧，这里不支持。 * @param content * 带占位符正文 * @param mailTypes * 可变参数，填充占位符 * @throws Exception */
    	public void sendCompleteHtml(String content, List<MailType> mailTypes, MailMessage mailMessage) throws Exception { 
    		System.getProperties().setProperty("mail.mime.splitlongparameters", "false");
    		if (mailMessage.getFrom() == null || "".equals(mailMessage.getFrom())) { 
    			mailMessage.setFrom(from);
    			mailMessage.setFromName(fromName);
    		}
    		MimeMessage message = javaMailSender.createMimeMessage();
    		MimeMessageHelper helper = new MimeMessageHelper(message, true);
    		helper.setFrom(mailMessage.getFrom());
    		helper.setTo(mailMessage.getTo());
    		if (mailMessage.getCc() != null && mailMessage.getCc().length > 0)
    			helper.setCc(mailMessage.getCc());
    		helper.setSubject(mailMessage.getSubject());
    		String msg = getContent(content, mailTypes);
    		helper.setText(msg, true);
    		for (MailType item : mailTypes) { 
    			switch (item.getType()) { 
    			case MailType.TYPE_FILE:
    				if (item != null) { 
    					InlineFile inlineFile = (InlineFile) item;
    					helper.addInline(inlineFile.getCid(), new File(inlineFile.getFilePath()));
    				}
    				break;
    			case MailType.TYPE_ATTACH:
    				if (item != null) { 
    					AttachFile attachFile = (AttachFile) item;
    					helper.addAttachment(MimeUtility.encodeText(attachFile.getFileName()),
    							new File(attachFile.getFilePath()));
    				}
    				break;
    			}
    		}
    		try{ 
    			javaMailSender.send(message);
    		}catch(MailException e){ 
    			logger.error("邮件发送过程出错，重发一次。",e);
    			javaMailSender.send(message);
    		}
    		logger.info("完整的邮件已经发送。");
    
    	}
    
    	/** * 解析占位符 * * @param content * 字符串，带占位符{},有多少个{},就要有多少个MailType * @param mailTypes * MailType填充参数, 注：换行需主动添加 * @return 解析后的正文 * @throws MessagingException * @throws IOException */
    	private String getContent(String content, List<MailType> mailTypes) throws MessagingException, IOException { 
    		String bodyPrefix = "<html><body>";
    		String bodySuffix = "</body></html>";
    		StringBuffer sb = new StringBuffer();
    		sb.append(bodyPrefix);
    		for (MailType item : mailTypes) { 
    			if (content.length() < 1)
    				break;
    
    			int index = content.indexOf(DELIM_STR);
    			if (index == -1)
    				break;
    			sb.append(content.substring(0, index));
    			switch (item.getType()) { 
    			case MailType.TYPE_FILE:
    				if (item != null) { 
    					InlineFile inlineFile = (InlineFile) item;
    					sb.append("<img src=\'cid:" + inlineFile.getCid() + "\' />");
    				}
    				break;
    			case MailType.TYPE_TEXT:
    				TextString textString = (TextString) item;
    				sb.append(textString.getText());
    				break;
    			case MailType.TYPE_JSON:
    				JsonTable json = (JsonTable) item;
    				sb.append(genReportData(json));
    				
    				break;
    			}
    			content = content.substring(index + 2);
    		}
    		sb.append(content);
    		sb.append(bodySuffix);
    		return sb.toString();
    	}
    
    	/** * 根据Json字符串，生成有序的表格 * * @param jsonTable * json转table实体 * @return 表格字符串 * @throws IOException */
    	private String genReportData(JsonTable jsonTable) throws IOException { 
    		JSONArray ja = (JSONArray) JSON.parse(jsonTable.getData(), Feature.OrderedField);
    		StringBuilder sb = new StringBuilder();
    		try { 
    			sb.append("<table border=\"1\" style=\"border-collapse:collapse;font-size:14px\">\n");
    			sb.append("<caption align = \"left\">");
    			sb.append(jsonTable.getTitle());
    			sb.append("</caption>\n");
    			JSONObject jsonFirst = (JSONObject) ja.get(0);
    			sb.append("<tr>\n");
    			for (String key : jsonFirst.keySet()) { 
    				sb.append("<td>");
    				sb.append(jsonFirst.get(key));
    				sb.append("</td>\n");
    			}
    
    			sb.append("</tr>\n");
    			ja.remove(0);
    			for (Object column : ja) { 
    				sb.append("<tr>\n");
    				JSONObject json = (JSONObject) column;
    				for (String key : jsonFirst.keySet()) { 
    					sb.append("<td>");
    					sb.append(json.get(key));
    					sb.append("</td>\n");
    				}
    
    				sb.append("</tr>\n");
    			}
    
    			sb.append("</table>\n");
    		} catch (Exception e) { 
    			e.printStackTrace();
    		}
    		return sb.toString();
    	}
    
    	public String getFrom() { 
    		return from;
    	}
    
    	public void setFrom(String from) { 
    		this.from = from;
    	}
    
    	public JavaMailSender getJavaMailSender() { 
    		return javaMailSender;
    	}
    
    	public void setJavaMailSender(JavaMailSender javaMailSender) { 
    		this.javaMailSender = javaMailSender;
    	}
    
    	public String getFromName() { 
    		return fromName;
    	}
    
    	public void setFromName(String fromName) { 
    		this.fromName = fromName;
    	}
    }

这里的MailService定义了多种邮件发送方式，包含普通文本、html、内嵌图片、附件、表格等。因此需要我们定义多种实体。

### 三、测试 ###

新建一个MailRest,用来测试邮件发送：

package com.cff.springbootwork.mail.web;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.cff.springbootwork.mail.service.MailService;
    
    
    @RestController
    @RequestMapping("/mail")
    public class MailRest { 
    	@Autowired
    	MailService mailService;
    	
    	@RequestMapping(value = "/mail/{to}", method = {  RequestMethod.GET })
    	public String mail(@PathVariable("to") String to) { 
    		String content = "直接登录网页 看发邮件吗，不能发的话 asdasd";
    		mailService.sendSimpleMail(to, content, content, true);
    		return "hello,world";
    	}
    	
    }

### 四、过程中用到的邮件类型实体 ###

MailMessage邮件实体：

package com.cff.springbootwork.mail.type;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /** * mail实体，使用Builder生成 例: new MailMessage.Builder().to(to).build(); * @author fufei * */
    public class MailMessage { 
    	private String from;
    	private String fromName;
    	private List<String> to;
    	private List<String> cc;
    	private String subject;
    
    	MailMessage(Builder builder) { 
    		this.from = builder.from;
    		this.to = builder.to;
    		this.cc = builder.cc;
    		this.subject = builder.subject;
    		this.fromName = builder.fromName;
    	}
    
    	public static class Builder { 
    		private String from;
    		private String fromName;
    		private List<String> to = new ArrayList<String>();
    		private List<String> cc = new ArrayList<String>();
    		private String subject;
    
    		public Builder() { 
    
    		}
    
    		/** * 添加发送人信息，为空则需要调用方主动设置 * @param from 发送人邮件字符串 * @return */
    		public Builder from(String from) { 
    			this.from = from;
    			return this;
    		}
    		
    		/** * 添加发送人信息，为空则需要调用方主动设置 * @param from 发送人邮件字符串 * @return */
    		public Builder fromName(String fromName) { 
    			this.fromName = fromName;
    			return this;
    		}
    
    		/** * 添加收件人 * @param toAddr String * @return */
    		public Builder addTo(String toAddr) { 
    			to.add(toAddr);
    			return this;
    		}
    		
    		/** * 添加收件人列表 * @param toAddr String * @return */
    		public Builder addTo(List<String> toAddr) { 
    			to.addAll(toAddr);
    			return this;
    		}
    
    		/** * 设置收件人列表 * @param to 收件人数组 * @return */
    		public Builder to(List<String> to) { 
    			this.to = to;
    			return this;
    		}
    
    		/** * 添加抄送人 * @param ccAddr * @return */
    		public Builder addCc(String ccAddr) { 
    			cc.add(ccAddr);
    			return this;
    		}
    		
    		/** * 添加抄送人列表 * @param ccAddr * @return */
    		public Builder addCc(List<String> ccAddr) { 
    			cc.addAll(ccAddr);
    			return this;
    		}
    
    		/** * 设置抄送人列表 * @param cc * @return */
    		public Builder cc(List<String> cc) { 
    			this.cc = cc;
    			return this;
    		}
    
    		/** * 设置主题 * @param subject * @return */
    		public Builder subject(String subject) { 
    			this.subject = subject;
    			return this;
    		}
    		
    		/** * 生成MailMessage * @return MailMessage */
    		public MailMessage build() { 
    			if (to.size() < 1)
    				throw new IllegalStateException("邮件接收人为空!");
    			return new MailMessage(this);
    		}
    	}
    
    	public String getFrom() { 
    		return from;
    	}
    
    	public void setFrom(String from) { 
    		this.from = from;
    	}
    
    	public String getFromName() { 
    		return fromName;
    	}
    
    	public void setFromName(String fromName) { 
    		this.fromName = fromName;
    	}
    
    	public String[] getTo() { 
    		String[] array = new String[to.size()];
    		String[] s = to.toArray(array);
    		return s;
    	}
    
    	public String[] getCc() { 
    		if (cc.size() < 1)
    			return null;
    		String[] array = new String[cc.size()];
    		String[] s = cc.toArray(array);
    		return s;
    	}
    
    	public String getSubject() { 
    		return subject;
    	}
    }

MailType邮件类型接口：

package com.cff.springbootwork.mail.type;
    
    /** * 邮件类型 * @author fufei * */
    public abstract class MailType { 
    	public final static char TYPE_FILE = 'F';
    	public final static char TYPE_ATTACH = 'A';
    	public final static char TYPE_TEXT = 'T';
    	public final static char TYPE_JSON = 'J';
    
    	public abstract char getType();
    }

详细完整的邮件类型，可以访问[品茗IT-博客《SpringBoot入门建站全系列（十）邮件发送功能》][IT-]进行查看

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