SpringBoot配置文件与配置类的属性映射方式

一、在pom文件中加入依赖

目录结构

在这里插入图片描述
在实体类中会出现错误，然后点击这个网址会有需要的依赖
网址：
https://docs.spring.io/spring-boot/docs/2.1.6.RELEASE/reference/html/configuration-metadata.html#configuration-metadata-annotation-processor
引入的依赖为：

<dependency><groupId> org.springframework.boot </groupId><artifactId> spring-boot-configuration-processor </artifactId><optional> true </optional></dependency>

<?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><!--继承父工程--><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.6.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.william</groupId><artifactId>day01_springboot_initializr</artifactId><version>0.0.1-SNAPSHOT</version><name>day01_springboot_initializr</name><description>Demo project for Spring Boot</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId> org.springframework.boot </groupId><artifactId> spring-boot-configuration-processor </artifactId><optional> true </optional></dependency><!--spring boot开发工具包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId></dependency><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></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

二、application.yml

#配置对象
person:name: zhangsanage: 19date: 2019/09/09# 数组配置city:- beijing- tianjin- shanghai- chongqing# 配置集合
student:
- name: zhangsanage: 18score: 100
- name: lisiage: 28score: 88
- name: wangwuage: 38score: 90
#注意事项：在key与value直接需要加入空格，对大小写敏感。
server:port: 8081servlet:context-path: /demo

三、application.properties

server.port=8081
server.servlet.context-path=/demo

四、Person

需要提供get/set方法和toString方法

还需要注解@Component

需要注解@ConfigurationProperties(prefix = “person”)

使用注解@ConﬁgurationProperties映射

通过注解@ConﬁgurationProperties(preﬁx=’'配置文件中的key的前缀")可以将配置文件中的配置自动与实体进行映射。
使用@ConﬁgurationProperties方式必须提供Setter方法，使用@Value注解不需要Setter方法

package com.william.day01_springboot_initializr.domain;import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;import java.util.Arrays;
import java.util.Date;/*** @author ：lijunxuan* @date ：Created in 2019/6/27  19:29* @description ：* @version: 1.0*/
@Component
@ConfigurationProperties(prefix = "person")
public class Person {private String name;private String age;private Date date;private String []  city;@Overridepublic String toString() {return "Person{" +"name='" + name + '\'' +", age='" + age + '\'' +", date=" + date +", city=" + Arrays.toString(city) +'}';}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public Date getDate() {return date;}public void setDate(Date date) {this.date = date;}public String[] getCity() {return city;}public void setCity(String[] city) {this.city = city;}
}

五、HelloController

1、使用注解@Value映射

@value注解将配置文件的值映射到Spring管理的Bean属性值

package com.william.day01_springboot_initializr.controller;import com.william.day01_springboot_initializr.domain.Person;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** @author ：lijunxuan* @date ：Created in 2019/6/27  17:20* @description ：* @version: 1.0*/
@RestController
public class HelloController {@AutowiredPerson person;@Value("${person.name}")private String name;@Value("${person.age}")private String age;@RequestMapping("/hello")public String hello(){return String.format("hello world  你好！世界！1234222 name = %s!! age = %s!! person = %s !!",name,age,person);// return String.format("hello world  你好！世界！1234222 person = %s !!",person);}
}