spring boot 使用@ConfigurationProperties

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

    }

}

原文地址：https://www.cnblogs.com/liaojie970/p/8043150.html