IDEA的Springboot工程手动正确配置了yml配置文件无法识别并获取其中的属性，换回properties文件就能识别上了

一、问题场景

最近在学习springboot框架自定义starter时碰上一个问题，场景如下：

三个模块 aliyun-oss-spring-boot-starter（简写starter）、aliyun-oss-spring-boot-autoconfiguration（简写auto）和springboot-autoconfiguration-test （简写test）分别为阿里云oss功能的依赖管理模块、将图片上传至oss的具体功能实现模块和测试模块。（目录结构如下）

二、具体实现

starter：（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 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>3.3.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.itheima</groupId>
    <artifactId>aliyun-oss-spring-boot-starter</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>aliyun-oss-spring-boot-starter</name>
    <description>aliyun-oss-spring-boot-starter</description>
    <url/>

    <licenses>
        <license/>
    </licenses>

    <developers>
        <developer/>
    </developers>

    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>

    <properties>
        <java.version>17</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <!--        引入阿里云configuration包-->
        <dependency>
            <groupId>com.itheima</groupId>
            <artifactId>aliyun-oss-spring-boot-configuration</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>


</project>

auto:

AliOSSProperties.java:

（复制封装阿里云oss的对应容器信息，从配置文件中读入）

package com.itheima;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;


@Data
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliOSSProperties {
    private String endpoint;
    private String bucketName;
}

application.yml文件：

（我在使用此文件作为配置文件的时候，是将默认生成且优先级更高的properties文件删除了的）

aliyun:
  oss:
    endpoint: https://oss-cn-hangzhou.aliyuncs.com
    bucket-name: my

application.properties文件： 

aliyun.oss.bucket-name=my
aliyun.oss.endpoint=https://oss-cn-hangzhou.aliyuncs.com

AliOSSUtils.java:

package com.itheima;

import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyuncs.exceptions.ClientException;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.UUID;

/**
 * 阿里云 OSS 工具类
 */
@Data
public class AliOSSUtils {


    private AliOSSProperties aliOSSProperties;

    /**
     * 实现上传图片到OSS
     */
    public String upload(MultipartFile file) throws IOException, ClientException {
        String endpoint = aliOSSProperties.getEndpoint();
        String bucketName = aliOSSProperties.getBucketName();
        // 获取上传的文件的输入流
        InputStream inputStream = file.getInputStream();

        // 避免文件覆盖
        String originalFilename = file.getOriginalFilename();
        String fileName = UUID.randomUUID().toString() + originalFilename.substring(originalFilename.lastIndexOf("."));

        // 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        //上传文件到 OSS
        OSS ossClient = new OSSClientBuilder().build(endpoint,credentialsProvider);
        ossClient.putObject(bucketName, fileName, inputStream);

        //文件访问路径
        String url = endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + fileName;
        // 关闭ossClient
        ossClient.shutdown();
        return url;// 把上传到oss的路径返回
    }

    public AliOSSProperties getAliOSSProperties() {
        return aliOSSProperties;
    }

    public void setAliOSSProperties(AliOSSProperties aliOSSProperties) {
        this.aliOSSProperties = aliOSSProperties;
    }
}

AliOSSAutoConfiguration.java:

此类为自动配置类，负责生成工具类AliOSSUtils并将其交由springboot的ioc容器管理

package com.itheima;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
@EnableConfigurationProperties(AliOSSProperties.class)
public class AliOSSAutoConfiguration {

    @Bean
    public AliOSSUtils aliOSSUtils(AliOSSProperties aliOSSProperties){
        AliOSSUtils aliOSSUtils=new AliOSSUtils();
        aliOSSUtils.setAliOSSProperties(aliOSSProperties);
        return aliOSSUtils;
    }
}

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 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>3.3.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.itheima</groupId>
    <artifactId>aliyun-oss-spring-boot-configuration</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>aliyun-oss-spring-boot-configuration</name>
    <description>aliyun-oss-spring-boot-configuration</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

<!--        引入lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

<!--        引入web起步依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--阿里云OSS依赖-->
        <dependency>
            <groupId>com.aliyun.oss</groupId>
            <artifactId>aliyun-sdk-oss</artifactId>
            <version>3.17.4</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>javax.activation</groupId>
            <artifactId>activation</artifactId>
            <version>1.1.1</version>
        </dependency>

        <!-- no more than 2.3.3-->
        <dependency>
            <groupId>org.glassfish.jaxb</groupId>
            <artifactId>jaxb-runtime</artifactId>
            <version>2.3.3</version>
        </dependency>

        <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>

test:

UploadController类：

（一个简单的处理请求的类，注入阿里云工具类AliOSSUtils实现上传功能）

package com.itheima.controller;

import com.itheima.AliOSSUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

@RestController
public class UploadController {

    @Autowired
    AliOSSUtils aliOSSUtils;

    @PostMapping("/upload")
    public String upload(MultipartFile image) throws Exception {
        //上传文件到阿里云 OSS
        String url= aliOSSUtils.upload(image);
        return url;
    }

}

然后还有一个springboot工程的启动类，pom.xml文件中引入了starter模块，相当于自动将starter和auto两个模块的依赖都引入了，直接能使用上传到阿里云oss的功能了。

三、运行测试

1、启动项目：

使用两种配置文件均成功启动无报错。

2、postman测试：

（文件大小五十几KB不大）

a、properties文件时：

如下图，正常获得由oss容器自动生成的图片的URL

b、yml文件时：

注释properties文件，配置yml文件：

postman再次发送测试：

发现报500错误。调试时发现：是这个属性类没有从配置文件成功拿到对应的属性，导致之后的一个方法报空指针异常。

怀疑是ConfigurationProperties注解失效，把网上翻了个底朝天，最后找到一个帖子如下：

尝试将yml文件换回properties就好了。

四、总结

虽然问题解决了，但是还是不知道原因，大佬们有谁知道吗！！！？

解决问题的原文链接：https://www.cnblogs.com/qq3245792286/p/16229675.html