SpringBoot配置文件与配置类的属性映射方式

た入场券 2021-12-21 05:09 261阅读 0赞

# 一、在pom文件中加入依赖 #

## 目录结构 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70]  
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][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>
        
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.6.RELEASE</version>
            <relativePath/> 
        </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>
            
            <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: zhangsan
      age: 19
      date: 2019/09/09
      # 数组配置
      city:
      - beijing
      - tianjin
      - shanghai
      - chongqing
    
    # 配置集合
    student:
    - name: zhangsan
      age: 18
      score: 100
    - name: lisi
      age: 28
      score: 88
    - name: wangwu
      age: 38
      score: 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: 8081
      servlet:
        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;
    
        @Override
        public 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 {
        @Autowired
        Person 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);
        }
    }

# 七、测试 结果 #

![在这里插入图片描述][20190627201652583.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM5MTc5OTkz_size_16_color_FFFFFF_t_70]: /images/20211221/8f9edb61a0964cc4b4ef2c5499565e17.png
[https_docs.spring.io_spring-boot_docs_2.1.6.RELEASE_reference_html_configuration-metadata.html_configuration-metadata-annotation-processor]: https://docs.spring.io/spring-boot/docs/2.1.6.RELEASE/reference/html/configuration-metadata.html#configuration-metadata-annotation-processor
[20190627201652583.png]: /images/20211221/2d01b1e5234e4794ab15211baedca898.png