SpringBoot|SpringBoot yaml语法与数据读取操作详解 SpringBootyaml语法与数据读取操作

yaml
yaml语法规则

字面值表示方式：
数组表示方式：
对象数组格式：
对象数组缩略格式：

读取yaml数据

编写yaml文件
读取单一数据
读取二级数据
读取数组数据
读取服务器端口号
读取对象属性
封装全部数据到Environment对象
读取yaml引用类型属性数据

application.yml
MyDataSource
读取数据

变量的引用

application.yml
读取数据

context-path

@Autowired报错解决方案

yaml YAML是一种数据序列化格式。
yaml扩展名

.yaml
.yml（主流）

yaml语法规则

大小写敏感
属性层次关系使用多行描述，每行结尾使用冒号结束
使用缩进表示层级关系，同层左侧对齐，只允许使用空格(不允许使用Tab键)
属性值前面添加空格(属性名与属性值之间使用冒号+空格作为分隔)
#表示注释

字面值表示方式：

boolean: true
float: 3.14
int: 15
#表示空
null: ~
string: xiaofeixia
date: 2022-7-9
#日期与时间用T连接
datetime: 2022-7-9T12:00:30+02:00

数组表示方式：

likes:
- music
- draw
- game
likes1: [music,draw,game]

对象数组格式：

user2:
- name: xiaofeixia
age: 22
- name: xiaomage
age: 26
user3:
-
name: xiaofeixia
age: 22
-
name: xiaomage
age: 27

对象数组缩略格式：

user4: [{name:xiaofeixia,age:21},{name:xiaofeixia,age:22}]

读取yaml数据使用@Value读取单个数据，属性名引用方式：${一级属性名.二级属性名}

编写yaml文件

server:
port: 81
country: china
province: henan
city: zhengzhou
area: shangqiu
party: true
birthday: 2022-11-11
user8:
name: xiaofeixia
age: 22
user1:
name: xiaofeixia
age: 22
a:
B:
C:
d:
e: abc
likes:
- music
- draw
- game
likes1: [music,draw,game]
user2:
- name: xiaofeixia
age: 22
- name: xiaomage
age: 26
user3:
-
name: xiaofeixia
age: 22
-
name: xiaomage
age: 27
user4: [{name:xiaofeixia,age:21},{name:xiaofeixia,age:22}]

读取单一数据

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {//读取yaml数据中的单一数据@Value("${country}")public String country1; @GetMappingpublic String ById(){System.out.println("springboot is running..."); System.out.println("country=="+country1); //country==chinareturn "springboot is running..."; }}

读取二级数据

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Value("${user8.name}")public String username; @GetMappingpublic String ById(){System.out.println("springboot is running..."); System.out.println("username=="+username); //username==xiaofeixiareturn "springboot is running..."; }}

读取数组数据

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController { @Value("${likes[0]}")public String likes1; @GetMappingpublic String ById(){System.out.println("springboot is running..."); System.out.println("likes1=="+likes1); //likes1==musicreturn "springboot is running..."; }}

读取服务器端口号

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Value("${server.port}")public String port; @GetMappingpublic String ById(){System.out.println("springboot is running..."); System.out.println("port=="+port); //port==81return "springboot is running..."; }}

读取对象属性

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Value("${user2[0].age}")public String age2; @GetMappingpublic String ById(){System.out.println("springboot is running..."); System.out.println("age2=="+age2); //age2==22return "springboot is running..."; }}

封装全部数据到Environment对象

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Autowiredprivate Environment env; @GetMappingpublic String ById(){System.out.println(env.getProperty("server.port")); System.out.println(env.getProperty("user8.name")); return "springboot is running..."; }}

读取yaml引用类型属性数据

application.yml

【SpringBoot|SpringBoot yaml语法与数据读取操作详解】server:
port: 81
#创建类用于封装下面的数据
#由spring去加载数据到对象中，一定要告诉spring加载这组信息
#使用的时候直接从spring中获取信息
datasource:
driver: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/springboot
username: root
password: root

MyDataSource 自定义对象封装指定数据
1.定义数据模型封装yaml文件中对应的数据

package com.jkj; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; //2.定义spring的管控Bean@Component//3.指定加载数据@ConfigurationProperties(prefix = "datasource")public class MyDataSource {private String driver; private String url; private String username; private String password; public String getDriver() {return driver; }public void setDriver(String driver) {this.driver = driver; }public String getUrl() {return url; }public void setUrl(String url) {this.url = url; }public String getUsername() {return username; }public void setUsername(String username) {this.username = username; }public String getPassword() {return password; }public void setPassword(String password) {this.password = password; }@Overridepublic String toString() {return "MyDataSource{" +"driver='" + driver + '\'' +", url='" + url + '\'' +", username='" + username + '\'' +", password='" + password + '\'' +'}'; }}

读取数据

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Autowiredprivate MyDataSource myDataSource; @GetMappingpublic String ById(){System.out.println(myDataSource); //MyDataSource{driver='com.mysql.jdbc.Driver', url='jdbc:mysql://localhost/springboot', username='root', password='root'}return "springboot is running..."; }}

变量的引用
application.yml

server:
port: 81
baseDir: E:\window
tempDir: ${baseDir}\temp

读取数据

package com.jkj.controller; import com.jkj.MyDataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController@RequestMapping("/yamlBooks")public class BookController {@Value("${tempDir}")public String temp; @GetMappingpublic String ById(){System.out.println("temp=="+temp); //temp==E:\window\tempreturn "springboot is running..."; }}

context-path
只写：