yaml的使用

1. 通过yaml给实体类赋值

先写一个实体类Person

@Component //把person注册到bean，相当于<bean id="" class="">
@ConfigurationProperties(prefix = "person") //通过注解配置person
public class Person {
    private String name;
    private String age;
    private Date birth;
    private Boolean happy;
    private Map<String,String> maps;
    private List<String> list;
    private Dog dog;

    public Person() {
    }


    public Person(String name, String age, Date birth, Boolean happy, Map<String, String> maps, List<String> list, Dog dog) {
        this.name = name;
        this.age = age;
        this.birth = birth;
        this.happy = happy;
        this.maps = maps;
        this.list = list;
        this.dog = dog;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

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

    public Date getBirth() {
        return birth;
    }

    public void setBirth(Date birth) {
        this.birth = birth;
    }

    public Boolean getHappy() {
        return happy;
    }

    public void setHappy(Boolean happy) {
        this.happy = happy;
    }

    public Map<String, String> getMaps() {
        return maps;
    }

    public void setMaps(Map<String, String> maps) {
        this.maps = maps;
    }

    public List<String> getList() {
        return list;
    }

    public void setList(List<String> list) {
        this.list = list;
    }

    public Dog getDog() {
        return dog;
    }

    public void setDog(Dog dog) {
        this.dog = dog;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age='" + age + '\'' +
                ", birth=" + birth +
                ", happy=" + happy +
                ", maps=" + maps +
                ", list=" + list +
                ", dog=" + dog +
                '}';
    }
}

2.在resources下创建一个application.yaml文件

在yaml的赋值方式

yaml的基本语法

#第一级类名，空格后才是上一级的属性
#给属性赋值在冒号后面要空格，否则无效，如：name: "李玲"
Person:
  name: "李玲"
  age: 7
  birth: 2000/7/7
  happy: false
  #Map的写法
  maps: {k1: k1,k2: k2}
  #list数组
  list:
    - code
    - music
    - girl
  Dog:
    name: 旺财
    age: 3

#Dog和Person是平级，以下的Dog不是Person的属性
Dog:
  name: 小黄
  age: 2

3.测试

springBoot项目自带的测试方法

@SpringBootTest
class SpringDemoApplicationTests {

    @Autowired //用注解自动装配
    private Person person;
    @Autowired
    private Dog dog;
    @Test
    void contextLoads() {

        System.out.println("person:"+person);
        System.out.println("Dog:"+dog);
    }

}

4.打印结果：

person:Person{
name='李玲', 
age='7', 
birth=Fri Jul 07 00:00:00 CST 2000, 
happy=false, maps={k1=k1, k2=k2}, 
list=[code, music, girl], 
dog=Dog{name='旺财', age='3'}
}

Dog:Dog{name='小黄', age='2'}

5.使用yaml要注意配置@ConfigurationProperties(prefix = "xxx")

以上用log打印Person和Dog类
必须要配置
@ConfigurationProperties(prefix = "person")
@ConfigurationProperties(prefix = "dog")
否则打印是空值

6.yaml 和 properties的区别

yaml的写法：

#普通的key-value
name: 李玲

#对象
student:
  name: liling
  age: 6

#内行写法
student: {name: liling,age: 6}

#数组
pets:
  - cat
  - dog
  - pig
#内行写法
pets: [cat,dog,pig]

properties的写法：

name=liling
student.name=liling
student.age= 6

person.pets.[0]=cat
person.pets.[1]=dog
person.pets.[2]=pig

7.总结：

yaml通熟易懂，写法简单明了，yaml对空格及其严格，层级关系需要空格来区分，上下左对齐为平级关系。