yaml syntax format, the use of yaml in springboot

yaml

YAML (/ˈjæməl/, ending sound like camel camel) is a highly readable format for expressing data serialization. YAML references a variety of other languages, including: C, Python, Perl, and takes inspiration from XML, the data format of email (RFC 2822). Clark Evans first published this language in 2001, and Ingy dot Net and Oren Ben-Kiki are also co-designers of this language. Several programming or scripting languages ​​currently support (or parse) this language.

YAML is a recursive acronym for "YAML Ain't a Markup Language" (YAML is not a markup language). When this language was developed, YAML actually meant: "Yet Another Markup Language" ( still a markup language ), but in order to emphasize that this language is data-centric rather than markup language-focused, and Rename with reverse acronym.

1.yaml syntax format

• key: value; there is a space between kv
• Case Sensitive
• Use indentation to indicate hierarchical relationships
• Tabs are not allowed for indentation, only spaces are allowed
• The number of spaces indented is not important, as long as the elements of the same level are left-aligned
• '#'Indicates a comment
• The string does not need to be quoted. If you want to add it, '单引号it "双引号means that the string content will be escaped/unescaped

2. Data type representation

• Literals: A single, indivisible value. date, boolean, string, number, null

k: v

• Object: A collection of key-value pairs. map, hash, set, object

行内写法： k: {
    
    k1:v1,k2:v2,k3:v3}
#或
 k:
  k1: v1
  k2: v2
  k3: v3

• Array: A group of values ​​arranged in order. array, list, ...

行内写法： k: [v1,v2,v3]
#或者
k:
 - v1
 - v2
 - v3

The use of yaml in springboot

1. @ConfigurationProperties annotation and bean creation

@ConfigurationProperties Annotation, used to bind the properties file or yml file configuration to the javabean component.

Create a Person bean component:

package com.robin.boot.bean;

import lombok.Data;
import lombok.ToString;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;

@ConfigurationProperties(prefix = "person") // 将application.yaml中前缀为person的数据绑定到person的bean组件中
@Component // 将person的javabean当作一个容器中的组件
@ToString
@Data
public class Person {
    
    
    private String userName;
    private Boolean boss;
    private Date birth;
    private Integer age;
    private Pet pet;
    private String[] hobbies;
    private List<String> animal;
    private Map<String, Object> score;
    private Set<Double> pinMoney;
    private Map<String, List<Pet>> allPets;
}

Create a dependent Pet class:

package com.robin.boot.bean;


import lombok.Data;
import lombok.ToString;

@ToString
@Data
public class Pet {
    
    
    private String name;
    private int age;
}

2. Write the controller

Use the @RequestMapping annotation to respond to the specified url path request mapping:

package com.robin.boot.controller;

import com.robin.boot.bean.Person;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    
    

    @Autowired // 自动装配
    Person person;

    @RequestMapping("/test") // 路径请求映射
    public Person person(){
    
    
        return person;
    }
}

3. Configure the application.yaml configuration file

Use the yaml syntax format to write and bind the corresponding Person attributes:

# yaml表示以上对象
person:
  userName: robin
  boss: true
  birth: 2001/08/09
  age: 21
  pet:
    name: 小白
    age: 3
  hobbies: [下棋,长跑,编程]
  animal:
    - 小狗
    - 小猫
    - 小猪
  score: {
    
    操作系统:88,数据结构:92,计网:97,计组:91}
  pinMoney:
    - 1500.01
    - 2009.99
  allPets:
    sick:
      - 小狗:
        name: 小黄
        age: 2
    healthy:
      - 小猫: {
    
    name: 胖橘,age: 4}
      - 小猪: {
    
    name: 大花,age: 1}

4. Open yaml prompt in pom.xml

The pom.xml configuration prompted by lombok and yaml:

		<!--  Lombok      -->
        <dependency>
            <groupId>cn.itlym.shoulder</groupId>
            <artifactId>lombok</artifactId>
            <version>0.1</version>
        </dependency>
        <!--   开启yml提示     -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>

Filter resource configuration-processor:

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <!--     将yml提示的configuration-processor 取消避免打包到jar中       -->
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.springframework.boot</groupId>
                            <artifactId>spring-boot-configuration-processor</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>

        </plugins>
    </build>

run view

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