spring boot 使用@ConfigurationProperties

水深无声 2022-11-04 13:30 112阅读 0赞

有时候有这样子的情景，我们想把配置文件的信息，读取并自动封装成实体类，这样子，我们在代码里面使用就轻松方便多了，这时候，我们就可以使用@ConfigurationProperties，它可以把同类的配置信息自动封装成实体类

首先在配置文件里面，这些信息是这样子滴

connection.username=admin
    connection.password=kyjufskifas2jsfs
    connection.remoteAddress=192.168.1.1

这时候我们可以定义一个实体类在装载配置文件信息

@Component
    @ConfigurationProperties(prefix="connection")
    public class ConnectionSettings {
    
        private String username;
        private String remoteAddress;
        private String password ;
    
        public String getUsername() {
            return username;
        }
        public void setUsername(String username) {
            this.username = username;
        }
        public String getRemoteAddress() {
            return remoteAddress;
        }
        public void setRemoteAddress(String remoteAddress) {
            this.remoteAddress = remoteAddress;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
    
    }

我们还可以把@ConfigurationProperties还可以直接定义在@bean的注解上，这是bean实体类就不用@Component和@ConfigurationProperties了

@SpringBootApplication
    public class DemoApplication{
    
        //...
    
        @Bean
        @ConfigurationProperties(prefix = "connection")
        public ConnectionSettings connectionSettings(){
            return new ConnectionSettings();
    
        }
    
        public static void main(String[] args) {
            SpringApplication.run(DemoApplication.class, args);
        }
    }

然后我们需要使用的时候就直接这样子注入

@RestController
    @RequestMapping("/task")
    public class TaskController {
    
    @Autowired ConnectionSettings conn;
    
    @RequestMapping(value = {"/",""})
    public String hellTask(){
        String userName = conn.getUsername();     
        return "hello task !!";
    }
    
    }

如果发现@ConfigurationPropertie不生效，有可能是项目的目录结构问题，

你可以通过@EnableConfigurationProperties(ConnectionSettings.class)来明确指定需要用哪个实体类来装载配置信息

@Configuration
    @EnableConfigurationProperties(ConnectionSettings.class)
     public class MailConfiguration { 
        @Autowired private MailProperties mailProperties; 
    
        @Bean public JavaMailSender javaMailSender() {
          // omitted for readability
        }
     }

[https://www.cnblogs.com/liaojie970/p/8043150.html][https_www.cnblogs.com_liaojie970_p_8043150.html]

[https_www.cnblogs.com_liaojie970_p_8043150.html]: https://www.cnblogs.com/liaojie970/p/8043150.html