yaml语法和用法

yaml语法

1.基本写法

key: value(注意:后有一个空格)
name: luo

2.对象的写法

person:
 name: value
 age: value
对象的行内写法：person{name:value,age:value}

3.数组的写法

pets:
 - cat
 - dog
 - pig
对象行内写法  pets:[cat,dog,pig]

yaml配置文件的作用 可以在实体类中注入值

根据ymal的语法，编写一个application.ymal文件

person:
  name: Spring
  sex: man
  age: 12
  maps:
    hobby: basketball
    color: bule
  lists:
    - code
    - girl
  dog:
    name: wangcai
    age: 3

我们先建立两个实体类

Dog

package com.google.pojo;

import org.springframework.stereotype.Component;

@Component//将这个类给spring托管自动注册成Bean
public class Dog {
    private String name;
    private int age;

    public Dog() {
    }

    public Dog(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "Dog{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Person

package com.google.pojo;

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

import java.util.List;
import java.util.Map;


@Component
@ConfigurationProperties(prefix = "person")
//@ConfigurationProperties作用：

//1.将配置文件中配置的每一个属性的值，映射到这个类中
//2.告诉springBoot将本类的所有属性和配置文件中的相关配置的属性进行绑定
//3.参数prefix='person':将配置文件中的person下面的所有属性一一对应



public class Person {
    private String name;
    private String sex;
    private int age;
    private Map<String,Object> maps;
    private List<Object> lists;
    private Dog dog;

    public Person() {
    }

    public Person(String name, String sex, int age, Map<String, Object> maps, List<Object> lists, Dog dog) {
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.maps = maps;
        this.lists = lists;
        this.dog = dog;
    }

    public String getName() {
        return name;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

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

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

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

    public List<Object> getLists() {
        return lists;
    }

    public void setLists(List<Object> lists) {
        this.lists = lists;
    }

    public Dog getDog() {
        return dog;
    }

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

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

在springBoot自带的test进行测试

package com.google;

import com.google.pojo.Person;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class Spring01ConfigApplicationTests {
    @Autowired//自动装配，前提是spring容器中存在person（前面Component已经将person注册到
	//spring容器中）
    private Person person;
    @Test
    void contextLoads() {
        System.out.println(person);
    }
}

测试结果

Person{name='Spring', sex='man', age=12, maps={hobby=basketball, color=bule}, lists=[code, girl], dog=Dog{name='wangcai', age=3}}

爆红问题

使用了ConfigrationProperties就会出现这样的问题

只需要导入一个依赖再重启就可以了

<!-- 导入配置文件处理器，配置文件进行绑定就会有提示，需要重启 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>