SpringBoot入门(二) springBoot使用yml配置

1.yml的标准结构

version: 2.0
server:
 port: 8081
 
spring:
 application:
  name: ztest-spb
 profiles:
  active: dev

2.系统中调用 格式

	env.getProperty("version"),
        env.getProperty("spring.application.name"),
        env.getProperty("spring.profiles.active"),
        env.getProperty("server.port")

3.注意 :号后边和值要有空格 如   version: 2.0  禁止 version:2.0

Caused by: org.yaml.snakeyaml.scanner.ScannerException: while scanning for the next token
found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)

 in 'reader', line 3, column 2:

.yml文本中禁止使用tab 做间隔 否则报以上错误

4.yml的赋值使用

    (1)使用特定的 @value*yml注解 给类中的属性注值 (类似从属性文件获取数据然后赋值)

    

@RestController
public class TestController {
	
	@Value(value="${spring.application.name}")
	private  String projectname;
	
	@RequestMapping("/hello")
	public  String hello(){
		return "hello "+projectname;
	}
}

        (2)将属性文件中的值 直接赋值给定义的对象

user
  

username: 111

age: king       //将属性赋值给对象

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix = "user")
public class UserProperties {

    private String username;

    private Integer age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username= username;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

            在类中直接自动装配就可以使用了

@RestController
public class Test2Controller {
	
	@Autowired
	UserProperties properties;
	
	@RequestMapping("/hello")
	public  String hello(){
		return "hello "+properties.getUsername();
	}
}