@ConfigurationProperties

原文链接：
https://blog.csdn.net/yingxiake/article/details/51263071

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 !!";
    }

}