application.properties 包含如下配置

test.config.host=127.0.0.1
test.config.port=7001
test.config.conI=AAAAAAAA

存在一个TestConfig类文章源自懂站帝-http://www.sfdkj.com/12856.html

public class TestConfig {
  private String host;
  private String port;
  private String conI;
}

要实现系统启动时能将application.properties中前缀为 test.config 的配置项文章源自懂站帝-http://www.sfdkj.com/12856.html

都初始化到一个TestConfig的@Bean上，文章源自懂站帝-http://www.sfdkj.com/12856.html

并能注入到其他@Component中文章源自懂站帝-http://www.sfdkj.com/12856.html

建立一个Spring boot Web项目

项目文件结构如下

Springboot中的自动配置类从application.properties取配置及注入

文章源自懂站帝-http://www.sfdkj.com/12856.html

POM 文件内容为

<?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 https://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>2.6.6</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.my.demo</groupId>
<artifactId>configTest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>config-Test</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
</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>

主类文件为 ConfigTestApplication 内容如下：

@ComponentScan(basePackages = { "com.my.demo.config" }) 这一项必须要有，文章源自懂站帝-http://www.sfdkj.com/12856.html

因为TestConfig类和主类不在一个包下文章源自懂站帝-http://www.sfdkj.com/12856.html

package com.my.demo.configTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.my.demo.config.TestConfig;
@RestController
@SpringBootApplication
@ComponentScan(basePackages = { "com.my.demo.config" })
public class ConfigTestApplication {
  @Autowired
  private TestConfig testConfigBean;
  @RequestMapping("/")
  public String index() {
    return "执行：" + testConfigBean.getHost();
  }
  public static void main(String[] args) {
    SpringApplication.run(ConfigTestApplication.class, args);
  }
}

TestConfig 文件内容如下，类上不需要加 @Component 注解。

package com.my.demo.config;
import org.springframework.boot.context.properties.ConfigurationProperties;
import lombok.Data;
@Data
@ConfigurationProperties(prefix = "test.config")
public class TestConfig {
  private String host;
  private String port;
  private String conI;
  private String name;
}

TestConfigCreater 文件内容为，这里注意EnableConfigurationProperties

有的文章说需要包含这个注解，配置才能自动生效，文章源自懂站帝-http://www.sfdkj.com/12856.html

个人试了一下，包含不包含没有区别，不知道是不是Springboot版本的原因文章源自懂站帝-http://www.sfdkj.com/12856.html

package com.my.demo.config;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@Configuration
//@EnableConfigurationProperties(TestConfig.class)
public class TestConfigCreater {
  @Bean
  public TestConfig testConfigBean() {
    log.info("创建testConfig...");
    return new TestConfig();
  }
}