第二篇 : Spring Boot配置文件详解

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SpringBoot使用一个全局的配置文件，配置文件名的

• application.properties
• application.yml

配置文件的作用 : SpringBoot底层都给我们配置好了，但有时候我们需要修改一些默认配置。

一、YMAL

1. YMAL与XML对比

YMAL :

serverport: 8081

XML :

<server><port>8081</port>
</server>

2. 基本语法

k:空格v : 表示一对键值对（空格必须有)
以空格的缩进来控制层级关系；空格多少无所谓，只要左对齐的一列数据，都是同一个层级的。

server:port: 8081path: /hello

3. 配置文件值注入

application.yml

server:port: 8081person:lastName: zhangsan # 也可写成(松散语法) last-name:zhansangage: 18boss: falsebirth: 2017/12/12map: {k1: v1, k2 : 12}list:- lisi- zhaoliudog:name: 史努比age: 2
cat:name: Tomage: 5

实体类 Person

package com.gf.entity;import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;import java.util.Date;
import java.util.List;
import java.util.Map;/*** 将配置文件中的配置，映射到这个组件中* @ConfigurationProperties: 告诉SpringBoot将本类所有属性和配置文件中相关的配置进行绑定*      prefix = "person" : 配置文件中那个下面的所有属性进行一一映射* 只有这个这个组件是容器中的组件，才能使用容器提供的@ConfigurationProperties的功能*/
@Component
@ConfigurationProperties(prefix = "person")
public class Person {private String lastName;private Integer age;private Boolean boss;private Date birth;private Map<String , Object> map;private List<Object> list;private Dog dog;public String getLastName() {return lastName;}public void setLastName(String lastName) {this.lastName = lastName;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Boolean getBoss() {return boss;}public void setBoss(Boolean boss) {this.boss = boss;}public Date getBirth() {return birth;}public void setBirth(Date birth) {this.birth = birth;}public Map<String, Object> getMap() {return map;}public void setMap(Map<String, Object> map) {this.map = map;}public List<Object> getList() {return list;}public void setList(List<Object> list) {this.list = list;}public Dog getDog() {return dog;}public void setDog(Dog dog) {this.dog = dog;}@Overridepublic String toString() {final StringBuilder sb = new StringBuilder( "{\"Person\":{" );sb.append( "\"lastName\":\"" ).append( lastName ).append( '\"' );sb.append( ",\"age\":" ).append( age );sb.append( ",\"boss\":" ).append( boss );sb.append( ",\"birth\":\"" ).append( birth ).append( '\"' );sb.append( ",\"map\":" ).append( map );sb.append( ",\"list\":" ).append( list );sb.append( ",\"dog\":" ).append( dog );sb.append( "}}" );return sb.toString();}
}

实体类 Dog

package com.gf.entity;public class Dog {private String name;private Integer age;public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}@Overridepublic String toString() {final StringBuilder sb = new StringBuilder( "{\"Dog\":{" );sb.append( "\"name\":\"" ).append( name ).append( '\"' );sb.append( ",\"age\":" ).append( age );sb.append( "}}" );return sb.toString();}
}

实体类 Cat

package com.gf.entity;import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;@Component
public class Cat {@Value( "${cat.name}" )private String name;@Value( "${cat.age}" )private Integer age;public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}@Overridepublic String toString() {final StringBuilder sb = new StringBuilder( "{\"Cat\":{" );sb.append( "\"name\":\"" ).append( name ).append( '\"' );sb.append( ",\"age\":" ).append( age );sb.append( "}}" );return sb.toString();}
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.gf</groupId><artifactId>springboot-config</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>springboot-config</name><description>Demo project for Spring Boot</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>1.5.9.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!-- 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></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

SpringBoot 测试类

package com.gf;import com.gf.entity.Cat;
import com.gf.entity.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;/*** SpringBoot单元测试* 可以在测试期间很方便的类似编码一样进行自动注入等容器的功能*/
@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootConfigApplicationTests {@AutowiredPerson person;@AutowiredCat cat;@Testpublic void contextLoads() {System.out.println(person);System.out.println(cat);}}

运行 SpringbootConfigApplicationTests 的到结果

{"Person": {"lastName": "zhangsan","age": 18,"boss": false,"birth": "Tue Dec 12 00:00:00 CST 2017","map": {k1 = v1,k2 = 12},"list": [lisi, zhaoliu],"dog": {"Dog": {"name": "史努比","age": 2}}}
}
{"Cat": {"name": "Tom","age": 5}
}

@Value获取值和@ConfigurationProperties获取值比较

如果说，我们只是在某个业务逻辑中需要获取一下配置文件中的某项值，使用**@Value**; 如果说，我们专门编写了一个javaBean来和配置文件进行映射，我们就直接使用**@ConfigurationProperties**;

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