1. 添加 AWS SDK for Java 和 Spring Boot Starter Web 依赖

在 Maven 或 Gradle 的项目中添加以下依赖：

Maven:

    com.amazonaws
    aws-java-sdk-s3
    1.11.375


    org.springframework.boot
    spring-boot-starter-web

Gradle:

dependencies {
    implementation 'com.amazonaws:aws-java-sdk-s3:1.11.375'
    implementation 'org.springframework.boot:spring-boot-starter-web'
}

2. 配置 AWS S3 认证信息

在 Spring Boot 的配置文件（application.properties 或 application.yml）中添加以下信息：

# AWS S3 认证信息
aws.accessKeyId=
aws.secretKey=
aws.s3.region=
aws.s3.bucket=

3. 创建 AWS S3 配置类

创建一个类来获取 AWS S3 认证信息，并创建 AmazonS3Client 对象：

import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AwsS3Config {

    @Value("${aws.accessKeyId}")
    private String accessKeyId;

    @Value("${aws.secretKey}")
    private String secretKey;

    @Value("${aws.s3.region}")
    private String region;

    @Value("${aws.s3.bucket}")
    private String bucketName;

    @Bean
    public AmazonS3 amazonS3() {
        BasicAWSCredentials credentials = new BasicAWSCredentials(accessKeyId, secretKey);
        AmazonS3 client = new AmazonS3Client(credentials);
        client.setRegion(region);
        return client;
    }
}

4. 创建 Controller 类

创建一个 Controller 来处理文件上传和下载请求：

import com.amazonaws.services.s3