[springboot framework] - springboot configuration file, another golden nine silver ten year

• application.properties

• application.yml(application.yaml)

1. application.properties The configuration file

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We can create  application.properties Configuration file to overwrite SpringBoot Default configuration , Can be in resources Create under folder  application.properties file , Here you can configure it manually Tomcat Port de coverage SpringBoot The default configuration is , We know Tomcat The default open port is 8080, We can go through  application.properties Configuration file to modify the default configuration ：

server.port=8888

After adding the configuration , Run the project

properties The file is written in the form of key value pairs , You can see , By modifying the application.properties The configuration file , Have already put Tomcat Port to 8888, Overwrites the previous configuration , because  properties In the past, more documents were used , More common , I won't talk too much here , Mainly right yml Learn from the configuration file .

2. application.yml(application.yaml) The configuration file

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YML The file format is YAML (YAML Aint Markup Language) The format of the document ,YAML It is an intuitive data serialization format that can be recognized by computer , And it's easy for humans to read , Easy to interact with scripting language , Can be supported YAML Library of different programming languages, program import , such as ： C/C++, Ruby, Python, Java, Perl, C#, PHP etc. .YML Files are data centric , Than traditional xml The way is more concise .YML The file extension can use .yml perhaps .yaml.

【1】yml Profile syntax

yml The configuration of can be divided into the following , We first in resources Create under the folder  application.yml The configuration file

• Configure common data

• Configure object data

• To configure Map data

• Configure array data

Configure common data ：

• grammar ： key: value

• eg：

name: onestar

Be careful ：value There is a space in front

Configure object data ：

• grammar 1：

• key:

key1: value1

key2: value2

• grammar 2：

• key: {key1: value1,key2: value2}

• eg：

person:

name: oneStar

age: 18

addr: yichun

# perhaps

person: {name: oneStar,age: 18,addr: yihcun}

Be careful ：key1 There is no limit to the number of spaces in front , stay yml In the syntax , The same indent represents the same level

To configure Map data ：

• To configure Map The data is the same as the configuration object data

• eg：

map:

key1: value1

key2: value2

Configure array data ：

• grammar 1

• key:

• value1

• value2

• grammar 2

• key: [value1,value2]

• eg：

city:

• beijing

• tianjin

• shanghai

• chongqing

# perhaps

city: [beijing,tianjin,shanghai,chongqing]

# The elements in the collection are in the form of objects

student:

• name: oneStar

age: 18

score: 100

• name: twoStar

age: 28

score: 88

• name: threeStar

age: 38

score: 90

Be careful ：value1 Between and - There is a space between

Two 、 Attribute mapping between configuration file and configuration class

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Configuration in profile , Whether it's properties The file or yml file , There are some configurations SpringBoot Will automatically identify , such as server.port=8888 To configure , But there are some custom configurations ,SpringBoot It doesn't automatically recognize , How to make SpringBoot Know your own configuration information , There are two ways ：

• Using annotations @Value mapping

• Using annotations @ConfigurationProperties mapping

1、 Using annotations @Value mapping

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We can go through @Value Annotation maps the values in the configuration file to a Spring Managed Bean Field on , Here we use  yml The document explains

• application.yml The configuration is as follows ：

person:

name: oneStar

age: 18

• Entity Bean The code is as follows ：

@Controller

public class QuickController {

@Value("${person.name}")

private String name;

@Value("${person.age}")

private int age;

@RequestMapping("/quick")

@ResponseBody

public String quick(){

return “name=”+name+",age="+age;

}

}

After operation , Browser access address ：http://localhost:8080/quick give the result as follows

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2、 Using annotations @ConfigurationProperties mapping

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Use Value Mapping can accurately match to a certain attribute , But if there are many properties , It brings inconvenience , therefore , You can also use  @ConfigurationProperties mapping , Through annotation @ConfigurationProperties(prefix=“ In the configuration file key The prefix of ”) The configuration in the configuration file can be automatically mapped to the entity

• application.yml The configuration is as follows ：

person:

name: oneStar

age: 19

• Entity Bean The code is as follows ：