SpringBoot的@ConfigurationProperties与Spring的@Value

男娘i 2023-08-17 17:19 118阅读 0赞

**利用全局配置文件进行值的注入+@ConfigurationProperties**  
1.添加依赖

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-configuration-processor</artifactId>
                <optional>true</optional>
            </dependency>
        </dependencies>

2.application.yml与application.properties  
application.yml

server:
       port: 8082
    
    person:
        name: zhangsan
        age: 20
        boss: false
        birth: 2019/9/30
        maps:
           k1: 12
           k2: 13
        lists:
          - lisi
          - wangwu
        dog:
           name: xiaotian
           age: 1

application.properties

server.port=8082
    
    person.name=zhangsan
    person.age=20
    person.birth=2019/9/30
    person.boss=false
    person.maps.k1=12
    person.maps.k2=13
    person.lists=lisi,wangwu
    person.dog.name=xiaotian
    person.dog.age=1

3.pojo类

//注册为容器组件
    @Component
    //将application.yml配置文件的值映射到Person
    //prefix指的是yaml文件中的前缀
    @ConfigurationProperties(prefix = "person")
    //数据校验
    @Validated
    public class Person { 
        private String name;
        private Integer age;
        @Email//必须是邮箱格式
        private String email;
        private Boolean boss;
        private Date birth;
    
        private Map<String,Object> maps;
        private List<Object> lists;
        private Dog dog;
    }

4.Controller中使用

@RestController
    @RequestMapping("/person")
    
    public class PersonController { 
    
        //自动注入 从容器中取
        @Autowired
        private Person person;
        
        @RequestMapping("/test")
        public String test(){ 
           return person.toString();
        }
    }

**利用全局配置文件进行值的注入+@Value**  
spring的@value注解

//注册为容器组件
    @Component
    public class Person { 
        @Value("${person.name}") //${}表达式从配置文件中读取
        private String name;
        @Value("#{11*2}") //#{表达式}
        private Integer age;
        @Value("true") //硬编码
        private Boolean boss;
        private Date birth;
    
        private Map<String,Object> maps;
        private List<Object> lists;
        private Dog dog;
    }

@ConfigurationProperties和@Value的比较

<table> 
 <thead> 
  <tr> 
   <th></th> 
   <th>@ConfigurationProperties</th> 
   <th>@Value</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>功能</td> 
   <td>批量注入配置文件属性(指定prefix)</td> 
   <td>一个一个指定</td> 
  </tr> 
  <tr> 
   <td>松散绑定</td> 
   <td>支持</td> 
   <td>不支持</td> 
  </tr> 
  <tr> 
   <td>#{}</td> 
   <td>不支持</td> 
   <td>支持</td> 
  </tr> 
  <tr> 
   <td>JSR303数据校验</td> 
   <td>支持</td> 
   <td>不支持</td> 
  </tr> 
  <tr> 
   <td>复杂类型封装</td> 
   <td>支持</td> 
   <td>不支持(Map等)</td> 
  </tr> 
 </tbody> 
</table>

适用场景  
如果为了在业务逻辑中简易的获取配置文件中的某个值，使用@Value，一次性  
如果javabean与配置文件进行复杂映射，使用@ConfigurationProperties，永久性