Springboot configuration

1. Basic grammar and expression of yml

1. Basic grammar of yaml

1. k: (space) v represents a key-value pair

key: value

2. Use indentation to indicate hierarchical relationships

key:
	child-key1: value1
	child-key2: value2

3. Attributes and values ​​are case sensitive
4. Comments
Use # for comments

#xxxxxxx
key: value

2. The expression of value

1. Object

Student:
	name: tom
	age: 11
#行内写法
Student: {
    
    name:tom,age:11}

2. Array

nums: 
	- 1
	- 2
	- 3
#行内写法
nums: {
    
    1,2,3}

Two, springboot configuration file

You can import the configuration file processor before writing, so that you will be prompted when writing yml

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

1. Injection of configuration file values

Prerequisite: The javabean corresponding to the configuration file must be placed in the IOC container, that is, using @Component annotation

Method 1
uses @ConfigurationProperties(prefix = "person") to set a value for binding, and set the properties of the class through this binding value in the configuration file.

javabean

@Component
@ConfigurationProperties(prefix = "person")
public class Person {
    
    
    private String lastName;
    private Integer age;
    private boolean boss;
    private Date date;

    private Map<String,Object> maps;
    private List<Object> list;
    private Dog dog;
    ....
}
@Component
public class Dog {
    
    
    private String name;
    private Integer age;
    ...
}

yml configuration file

person:
  lastname: zhangsan
  age: 11
  boss: true
  date: 2010/11/11
  maps: {
    
    k1: v1,k2: v2}
  list:
    - list1
    - list2
    - list3
  dog:
    name: xiaoming
    age: 2

result:

Person{lastName='zhangsan', age=11, boss=true, date=Thu Nov 11 00:00:00 CST 2010, maps={k1=v1, k2=v2, kw=v2}, list=[list1, list2, list3], dog=Dog{name='xiaoming', age=2}}

Method 2:
You can assign the value to the object by using @PropertySource to specify the properties configuration file

Configuration file

person.last-name=张三
person.age=11
person.boss=false
person.date=2021/2/2
person.maps.k1=v1
person.maps.kw=v2
person.list=a,x,c,v
person.dog.name = dog
person.dog.age = 15

javabean

/**
 * 将配置文件中的每一个属性的值映射到这个组件中
 * @ConfigurationProperties 高数springboot将本类中所有属性和配置文件中相关的配置进行绑定
 *      prefix 在配置文件中哪个下面的所有属性进行一一映射
 * 只有这个组件是容器中的组件，才能提供@ConfigurationProperties的功能
 *
 * @PropertySource 导入spring的配置文件，让配置文件中的内容生效
 */
@PropertySource(value = {
    
    "classpath:person.properties"})
@Component
@ConfigurationProperties(prefix = "person")
public class Person {
    
    
    private String lastName;
    private Integer age;
    private boolean boss;
    private Date date;

    private Map<String,Object> maps;
    private List<Object> list;
    private Dog dog;
    ...
}

result

Person{lastName='张三', age=11, boss=false, date=Tue Feb 02 00:00:00 CST 2021, maps={k1=v1, kw=v2}, list=[a, x, c, v], dog=Dog{name='dog', age=15}}

Method 3
Use @Value annotation to assign value to attribute

@Component
//@ConfigurationProperties(prefix = "person")
public class Person {
    
    

    @Value("zhangsan")
    private String lastName;
    @Value("11")
    private Integer age;
    private boolean boss;
    private Date date;

    private Map<String,Object> maps;
    private List<Object> list;
    private Dog dog;

result

Person{lastName='zhangsan', age=11, boss=false, date=null, maps=null, list=null, dog=null}

2, @Value get value and @ConfigurationProperties get value comparison

	@ConfigurationProperties	@Value
Features	Bulk injection of properties in configuration files	Specify one by one
Loosely bound (loose syntax)	stand by	not support
Game	not support	stand by
JSR303 data verification	stand by	not support
Complex type package	stand by	not support

Both the configuration file yml and properties can get the value;

If we just need to get a value in the configuration file in a certain business logic, use @Value;

If we say that we have specially written a javaBean to map with the configuration file, we will directly use @ConfigurationProperties;

3. Configuration file injection data verification

Before using verification, you need to import the dependency of field verification

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.4.Final</version>
        </dependency>

First use the @Validated annotation to decorate the class to be verified, and then use the following annotations to decorate the properties to be verified in the class

Borrow

@AssertFalse 校验false
@AssertTrue 校验true
@Email 校验是否是邮箱格式
@DecimalMax(value=,inclusive=) 小于等于value，
inclusive=true,是小于等于
@DecimalMin(value=,inclusive=) 与上类似
@Max(value=) 小于等于value
@Min(value=) 大于等于value
@NotNull  检查Null
@Past  检查日期
@Pattern(regex=,flag=)  正则
@Size(min=, max=)  字符串，集合，map限制大小
@Validate 对po实体类进行校验

Use mode three configuration file injection

@PropertySource(value = {
    
    "classpath:person.properties"})
@Component
@ConfigurationProperties(prefix = "person")
@Validated
public class Person {
    
    

//    @Value("zhangsan")
    @Email
    private String lastName;
//    @Value("11")
    private Integer age;
    private boolean boss;
    private Date date;

    private Map<String,Object> maps;
    private List<Object> list;
    private Dog dog;
	...
}

result:

java.lang.IllegalStateException: Failed to load ApplicationContext

4. Configuration file placeholder

#配置person的值
#配置文件的占位符${},如果想设没有的默认值可以用${name:defualt}
#通过使用${random.xxxx}随机数 例${random.value}、${random.int}、${random.long}、${random.int(10)}、${random.int[1024,65536]}等等
person.last-name=张三${random.int}
person.age=11
person.boss=false
person.date=2021/2/2
person.maps.k1=v1
person.maps.kw=v2
person.list=a,x,c,v
person.dog.name = ${person.hello:hello}dog
person.dog.age = 15

result

//结果1
Person{lastName='张三-1155973093', age=11, boss=false, date=Tue Feb 02 00:00:00 CST 2021, maps={k1=v1, kw=v2}, list=[a, x, c, v], dog=Dog{name='hellodog', age=15}}
//结果2
Person{lastName='张三1191295749', age=11, boss=false, date=Tue Feb 02 00:00:00 CST 2021, maps={k1=v1, kw=v2}, list=[a, x, c, v], dog=Dog{name='hellodog', age=15}}

5. Multiple Profile files

1. Multi-Profile file When
we write the main configuration file, the file name can be application-{profile}.properties/yml
. The configuration of

application.properties is used by default; application.properties file

#激活使用application-dev.properties配置文件
spring.profiles.active=dev

application-dev.properties file

#使用application-{profile},properties/yml取配置文件名
#默认使用的是application.properties
server.port=8081

application-prod.properties file

server.port=8082

result

2. yml supports multiple document blocks

#yml支持多文档块方式用 --- 来分割文档块
server:
  port: 8080
spring:
  profiles:
    active: prod
---
server:
  port: 8081
spring:
  profiles: dev #制定属于那个环境
---
server:
  port: 8082
spring:
  profiles: prod
---

result

6. Configuration file loading location

Springboot startup will scan the application.properties or application.yml file in the following location as the default configuration file for Spring boot

file:./config/

file:./

classpath:/config/

classpath:/

The priority is from high to low, and the configuration with high priority will override the configuration with low priority;

SpringBoot will load the main configuration file from these four locations; complementary configuration ;

You can also change the default configuration file location through spring.config.location

7. External configuration loading sequence

SpringBoot can also load the configuration from the following locations; priority from high to low; high priority configuration overrides low priority configuration, all configurations will form complementary configurations

1. Command line parameters

All configurations can be specified on the command line

java -jar spring-boot-02-config-02-0.0.1-SNAPSHOT.jar --server.port=8087 --server.context-path=/abc

Multiple configurations are separated by spaces; --configuration item=value

2. JNDI attributes from java:comp/env

3. Java system properties (System.getProperties())

4. Operating system environment variables

5. Random.* property value configured by RandomValuePropertySource

Search from the jar package to the jar package;

Load with profile first

6. Application-{profile}.properties or application.yml (with spring.profile) configuration file outside the jar package

7. Application-{profile}.properties or application.yml (with spring.profile) configuration file inside the jar package

Load again without profile

8. Application.properties or application.yml (without spring.profile) configuration file outside the jar package

9. Application.properties or application.yml (without spring.profile) configuration file inside the jar package

10.@PropertySource on @Configuration Annotated Class

11. The default properties specified by SpringApplication.setDefaultProperties

All supported configuration loading sources;

Refer to official documents