SpringBoot入门之SpringBoot读取yml配置文件, yml配置文件的语法 12

浅浅的花香味﹌ 2021-11-05 15:50 1088阅读 0赞

# 12. SpringBoot读取yml(yaml)文件 #

## 12.1 了解什么是yml(yaml)文件 ##

YML文件格式是YAML (YAML Aint Markup Language)编写的文件格式，YAML是一种直观的能够被电脑识别的的数据序列化格式，并且容易被人类阅读，容易和脚本语言交互的，可以被支持YAML库的不同的编程语言程序导入，比如： C/C++, Ruby, Python, Java, Perl, C\#, PHP等。**YML文件是以数据为核心的，比传统的xml方式更加简洁**。  
YML文件的扩展名可以是.yml或.yaml

## 12.2 yml配置文件的语法 ##

1.  配置普通数据  
    语法 key: value **注意,value之前一定要有个空格**

# 属性的配置
    name: acece

1.  配置对象数据  
    语法:  
    key:  
     key1: value1  
     key2: value2  
    或者  
    key: \{key1: value1,key2: value2\}

# 对象的配置
    person:
      name: acece
      age: 18
      addr: beijing
    
    # 行内对象配置
    person1: { name: acece,age: 18,addr: beijing}
    
    # 配置端口
    #改变application.properties
    server:
      port: 8890
      servlet:
        path: /demo1

**注意：key1前面的空格个数不限定，在yml语法中，相同缩进代表同一个级别**  
3. 配置Map数据  
语法:  
map:  
key: value1  
key: value2

# map结构
    map:
      key1: value1
      key2: value2

1.  配置数组(List, Set)数据  
    语法:  
    key:  
     - value1  
     - value2  
    或者  
    key: \[value1,value2\]

# 配置数据集合
    city:
      - beijing
      - tianjin
      - shanghai
      - chongqing
    
    # 或者行内注入
    city: [beijing,tianjin,shanghai,chongqing]
    
    # 集合中的元素是对象形式
    student:
      - name: zhangsan
        age: 18
        score: 100
      - name: lisi
        age: 28
        score: 88
      - name: wangwu
        age: 38
        score: 90
    
    # 或者使用行内注入
    student: [{ name: zhangsan,age: 18,score: 100},{ name: lisi,age: 28,score: 88},{ name: wangwu,age: 38,score: 90}]

**注意：value与之间的 - 之间存在一个空格**

## 12.3 SpringBoot配置信息的查询 ##

文档URL： [https://docs.spring.io/spring-boot/docs/2.0.1.RELEASE/reference/htmlsingle/\#common-application-properties][https_docs.spring.io_spring-boot_docs_2.0.1.RELEASE_reference_htmlsingle_common-application-properties]  
常用的配置摘抄如下：

# QUARTZ SCHEDULER (QuartzProperties)
    spring.quartz.jdbc.initialize-schema=embedded # Database schema initialization mode.
    spring.quartz.jdbc.schema=classpath:org/quartz/impl/jdbcjobstore/tables_@@platform@@.sql # Path to the SQL file to use to initialize the database schema.
    spring.quartz.job-store-type=memory # Quartz job store type.
    spring.quartz.properties.*= # Additional Quartz Scheduler properties.
    
    # ----------------------------------------
    # WEB PROPERTIES
    # ----------------------------------------
    
    # EMBEDDED SERVER CONFIGURATION (ServerProperties)
    server.port=8080 # Server HTTP port.
    server.servlet.context-path= # Context path of the application.
    server.servlet.path=/ # Path of the main dispatcher servlet.
    
    # HTTP encoding (HttpEncodingProperties)
    spring.http.encoding.charset=UTF-8 # Charset of HTTP requests and responses. Added to the "Content-Type" header if not set explicitly.
    
    # JACKSON (JacksonProperties)
    spring.jackson.date-format= # Date format string or a fully-qualified date format class name. For instance, `yyyy-MM-dd HH:mm:ss`.
    
    # SPRING MVC (WebMvcProperties)
    spring.mvc.servlet.load-on-startup=-1 # Load on startup priority of the dispatcher servlet.
    spring.mvc.static-path-pattern=/** # Path pattern used for static resources.
    spring.mvc.view.prefix= # Spring MVC view prefix.
    spring.mvc.view.suffix= # Spring MVC view suffix.
    
    # DATASOURCE (DataSourceAutoConfiguration & DataSourceProperties)
    spring.datasource.driver-class-name= # Fully qualified name of the JDBC driver. Auto-detected based on the URL by default.
    spring.datasource.password= # Login password of the database.
    spring.datasource.url= # JDBC URL of the database.
    spring.datasource.username= # Login username of the database.
    
    # JEST (Elasticsearch HTTP client) (JestProperties)
    spring.elasticsearch.jest.password= # Login password.
    spring.elasticsearch.jest.proxy.host= # Proxy host the HTTP client should use.
    spring.elasticsearch.jest.proxy.port= # Proxy port the HTTP client should use.
    spring.elasticsearch.jest.read-timeout=3s # Read timeout.
    spring.elasticsearch.jest.username= # Login username.

我们可以通过配置application.poperties 或者 application.yml 来修改SpringBoot的默认配置  
例如：  
application.properties文件

server.port=8888
    server.servlet.context-path=/demo

application.yml文件

server:
      port: 8888
      servlet:
        path: /demo

## 12.4 读取.yml配置文件 ##

### 12.4.1 读取普通数据 key: value ###

1.  resources包下创建application.yml配置文件  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70]

mail.host: acece.com2

1.  SpringBootReadThing.Test类中编写测试方法  
    注入application.yml中的key, 使用@\*\*$\{key\}\*\*注解注入

@Value("${mail.host}")
        private String mailHost;
    
        @Test
        public void readYml(){ 
            System.out.println("&&&&&&&&&&&&&&&&&&&&&&&&&"+mailHost);
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70 1]  
控制台打印出来value值, 读取成功~

### 12.4.2 读取对象数据 ###

1.  配置文件信息如下

mail:
      host: acece.comNew
      port: port=80New
      username: username=啊策策New
      password: password=1234563New

1.  MailProperties.java  
    不需要指定application.yml的位置.

package com.acece.domain;
    
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.stereotype.Component;
    
    /** * @author 啊策策 * @date 2019-08-06 19:09 */
    @ConfigurationProperties(prefix = "mail") //配置文件的前缀
    //@PropertySource(value = "classpath:mail.properties") //写明自定义的配置文件路径
    @Configuration //包扫描,springBoot启动自动创建该mailproperties对象
    public class MailProperties { 
    
        private String host;
        private String port;
        private String username;
        private String password;
    
        public String getHost() { 
            return host;
        }
    
        public void setHost(String host) { 
            this.host = host;
        }
    
        public String getPort() { 
            return port;
        }
    
        public void setPort(String port) { 
            this.port = port;
        }
    
        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;
        }
    
        @Override
        public String toString() { 
            return "MailProperties{" +
                    "host='" + host + '\'' +
                    ", port='" + port + '\'' +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }
    }

1.  SpringBootReadThing.Test类中编写测试方法

@Autowired
        private MailProperties mailProperties;
    
        @Test
        public void readYml2(){ 
            System.out.println(mailProperties);;
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70 2]

[https_docs.spring.io_spring-boot_docs_2.0.1.RELEASE_reference_htmlsingle_common-application-properties]: https://docs.spring.io/spring-boot/docs/2.0.1.RELEASE/reference/htmlsingle/#common-application-properties
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