SpringBoot 常用读取配置文件的三种方法详解

rabbitMQ:
  host: 127.0.0.1
  passWord: root
  port: 5672
  username: root

@Configuration
public class RabbitmqProperties {

    @Value("${rabbitmq.host}")
    private String rabbitmqHost;
    @Value("${rabbitmq.port}")
    private String rabbitmqPort;
    @Value("${rabbitmq.username}")
    private String rabbitmqUsername;
    @Value("${rabbitmq.password}")
    private String rabbitmqPassword;
}

@Component
public class PropertiesTest {

    @Autowired
    private RabbitmqProperties rabbitmqProperties;
}

@ConfigurationProperties(prefix = "rabbitmq")
public class RabbitmqProperties {
    private String host;
    private String port;
    private String username;
    private String password;
}

@Setter
@Configuration
@ConfigurationProperties(prefix = "rabbitmq")
public class RabbitmqProperties {
    private String host;
    private String port;
    private String username;
    private String password;
}

@Configuration
@EnableConfigurationProperties(RabbitmqProperties.class)
public class RabbitmqConfig {

    @Autowired
    private RabbitmqProperties prop;
    
    @Bean
    public Rabbitmq rabbitmq() {
        Rabbitmq mq = new Rabbitmq();
        mq.setHost(prop.getHost());
        mq.setPort(prop.getPort());
        mq.setUsername(prop.getUsername());
        mq.setPassword(prop.getPassword());
        return mq;
    }
}

@ConfigurationPropertiesScan
@SpringBootApplication
public class MainApplication {

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

@SpringBootApplication
public class MainApplication implements InitializingBean {
    
    @Autowired
    private Environment environment;

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

    @Override
    public void afterPropertiesSet() {
        String username = environment.getProperty("rabbitmq.username");
        System.out.println("rabbitmq当前用户名为:  " + username);
    }
}

# 二级缓存配置
l2cache:
  config:
    # 是否存储空值，默认true，防止缓存穿透
    allowNullValues: true
    # 组合缓存配置
    composite:
      # 是否全部启用一级缓存，默认false
      l1AllOpen: false
      # 是否手动启用一级缓存，默认false
      l1Manual: true
      # 手动配置走一级缓存的缓存key集合，针对单个key维度
      l1ManualKeySet:
      - userCache:user01
      - userCache:user02
      - userCache:user03
      - userCache:user04
      
    # 一级缓存
    caffeine:
      # 缓存刷新调度线程池的大小
      refreshPoolSize: 2
      # 写入后过期时间(秒)
      expireAfterWrite: 180
      # 访问后过期时间(秒)
      expireAfterAccess: 180
      # 初始化大小
      initialCapacity: 100
      # 最大缓存对象个数，超过此数量时之前放入的缓存将失效
      maximumSize: 300
      
    # 二级缓存
    redis:
      # 全局过期时间，单位毫秒，默认不过期
      defaultExpiration: 300000
      # 每个cacheName的过期时间，单位毫秒
      expires: {userCache: 300000,GoodsCache: 50000}
      # 缓存更新时通知其他节点的topic名称 默认 cache:redis:caffeine:topic
      topic: cache:redis:caffeine:topic

@Data
@ConfigurationProperties(prefix = "l2cache")
public class L2CacheProperties {
    
    private L2CacheConfig config;
}

@Data
public class L2CacheConfig {


    
    private boolean allowNullValues = true;
    
    
    private final Composite composite = new Composite();
    
    
    private final Caffeine caffeine = new Caffeine();

    
    private final Redis redis = new Redis();

    
    @Data
    public static class Composite {

        
        private boolean l1AllOpen = false;

        
        private boolean l1Manual = false;

        
        private Set<String> l1ManualKeySet = new HashSet<>();
    }
    
    
    @Data
    public static class Caffeine {
  
        
        private Integer refreshPoolSize = Runtime.getRuntime().availableProcessors();

        
        private long expireAfterWrite;

        
        private long refreshAfterWrite;

        
        private int initialCapacity;

        
        private long maximumSize;
    }

    
    @Data
    public static class Redis {

        
        private long defaultExpiration = 0;

        
        private Map<String, Long> expires = new HashMap<>();

        
        private String topic = "cache:redis:caffeine:topic";

    }
}

@Configuration
@EnableConfigurationProperties(L2CacheProperties.class)
public class CacheRedisCaffeineAutoConfiguration {

   @Autowired
   private L2CacheProperties l2CacheProperties;

   @Bean
   public RedisCaffeineCacheManager cacheManager() {
      return new RedisCaffeineCacheManager(l2CacheProperties.getConfig());
   }
}