Opening chapter

Today's websites basically have the function of email registration. After all, they can send users some spam recommendations on a regular basis It is very important.

To get back to the point, first of all, we need to make a few points clear

• ==What information do you need for email registration? = =

  Basic: email address, password, verification code

• ==Where is this information? = =

  Email address and password can't be said. They will be used frequently in the future. They have to be put into MySQL. As for the verification code, if it's put into MySQL, you have to create a new field for it, but it's not needed after registration. At this time, redis can solve this problem very well. Moreover, redis can also set the expiration time, and various data types are very convenient.

• ==How do I send mail? = =

  Spring Boot integrates JavaMailSender, which can be used after importing jar package. It is very convenient

Basic process

1. Click send email, generate a random verification code in the background and store it in redis, and set the validity period of 5 minutes
2. Click Register to compare the verification code entered by the user with that in redis

code implementation

1. Import Maven dependency

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

2. Configure mail and redis information

   spring:
     # Configure mail
     mail:
       host: smtp.qq.com #Mail server address
       username: xxx #Sender email
       password: xxx #Password
       default-encoding: utf-8
     # Configure redis
     redis:
       database: 0
       host: xxx
       port: 6379
   
   # Sender email
   beetle:
     sender:
       email: xxx
   

3. Reconfigure the RedisTemplate. The native RedisTemplate has serialization problems and needs to be specified again

   @Configuration
   @AutoConfigureAfter(CommunityApplication.class)
   public class RedisConfig {
   
       /**
        * Because the native redis auto assembly does not set the serialization method when storing the key and value, it creates its own redisTemplate instance
        * @param factory
        * @return
        */
       @Bean
       public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
           RedisTemplate<String, Object> template = new RedisTemplate<>();
           template.setConnectionFactory(factory);
           Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
           ObjectMapper om = new ObjectMapper();
           om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
           om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
           jackson2JsonRedisSerializer.setObjectMapper(om);
           StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
           // key is serialized by String
           template.setKeySerializer(stringRedisSerializer);
           // The hash key also uses String serialization
           template.setHashKeySerializer(stringRedisSerializer);
           // value serialization is jackson
           template.setValueSerializer(jackson2JsonRedisSerializer);
           // value serialization of hash adopts jackson
           template.setHashValueSerializer(jackson2JsonRedisSerializer);
           template.afterPropertiesSet();
           return template;
       }
   }
   
   

4. Write a method to send e-mail. So far, we have generated and stored the verification code in redis

   public Boolean sendEmail(String email) {
       if(!registered(email)){
           SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
           simpleMailMessage.setTo(email);
           simpleMailMessage.setSubject("test");
           //Generate 6-bit random number
           int code = (int) ((Math.random() * 9 + 1) * 100000);
           //Deposit in redis, expiration time 5 minutes
           redisTemplate.opsForValue().set(CODE_PRE + email, code, 5, TimeUnit.MINUTES);
           simpleMailMessage.setText("This is a test email with verification code:" + code);
           simpleMailMessage.setFrom(senderEmail);
           try {
               mailSender.send(simpleMailMessage);
               return true;
           } catch (MailException e) {
               log.error("There was an error sending the message,{}", e);
           }
       }
       return false;
   }
   

5. When registering, you need to check whether the verification code entered by the user is consistent with that in redis. I will not post other logics of registration

   public boolean checkCode(String email, Integer code) {
       Integer redisCode = (Integer) redisTemplate.opsForValue().get(CODE_PRE + email);
       return redisCode != null && redisCode.equals(code);
   }
   

Effect demonstration

• Registration interface

• redis data

• Mail received