Spring boot 集成 S3 进行文件读写删改

步骤一：添加依赖

首先，在Spring Boot项目中添加AWS S3相关的依赖。如果你使用Maven，可以在pom.xml中添加以下依赖：

<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>s3</artifactId>
    <version>2.17.27</version> <!-- 请根据需要选择最新版本 -->
</dependency>

步骤二：配置AWS凭证和Bucket信息

在application.properties中配置AWS凭证和S3 Bucket的信息。

aws.s3.bucketName=your-bucket-name
aws.region=your-region

步骤三：创建S3服务类

创建一个服务类来封装与S3的交互逻辑，包括上传、下载、删除和修改文件的方法。

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.*;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;

@Service
public class S3Service {

    private final S3Client s3Client;
    private final String bucketName;

    public S3Service(@Value("${aws.s3.bucketName}") String bucketName,
                     @Value("${aws.region}") String region) {
        this.s3Client = S3Client.builder()
                .region(Region.of(region))
                .credentialsProvider(DefaultCredentialsProvider.create())
                .build();
        this.bucketName = bucketName;
    }

    // 上传文件到S3
    public void uploadFile(String keyName, File file) {
        PutObjectRequest request = PutObjectRequest.builder()
                .bucket(bucketName)
                .key(keyName)
                .build();

        s3Client.putObject(request, RequestBody.fromFile(file));
    }

    // 从S3下载文件
    public File downloadFile(String keyName) throws IOException {
        GetObjectRequest request = GetObjectRequest.builder()
                .bucket(bucketName)
                .key(keyName)
                .build();

        File tempFile = File.createTempFile("s3file-", ".tmp");
        try (FileOutputStream fos = new FileOutputStream(tempFile);
             ResponseInputStream<GetObjectResponse> s3Object = s3Client.getObject(request)) {
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = s3Object.read(buffer)) != -1) {
                fos.write(buffer, 0, bytesRead);
            }
        }

        return tempFile;
    }

    // 从S3中删除文件
    public void deleteFile(String keyName) {
        DeleteObjectRequest request = DeleteObjectRequest.builder()
                .bucket(bucketName)
                .key(keyName)
                .build();

        s3Client.deleteObject(request);
    }

    // 修改S3中的文件（简单地重新上传覆盖）
    public void updateFile(String keyName, File newFile) {
        uploadFile(keyName, newFile);
    }

    // 从S3中读取文件的内容
    public String readFileContent(String keyName) throws IOException {
        File file = downloadFile(keyName);
        return new String(Files.readAllBytes(file.toPath()));
    }
}

步骤四：创建控制器类

创建一个控制器类，用于处理与S3交互的HTTP请求，如文件上传、下载、删除和更新。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

@RestController
@RequestMapping("/api/s3")
public class S3Controller {

    private final S3Service s3Service;

    @Autowired
    public S3Controller(S3Service s3Service) {
        this.s3Service = s3Service;
    }

    @PostMapping("/upload")
    public String uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
        File convFile = new File(file.getOriginalFilename());
        try (FileOutputStream fos = new FileOutputStream(convFile)) {
            fos.write(file.getBytes());
        }
        s3Service.uploadFile(file.getOriginalFilename(), convFile);
        return "File uploaded successfully: " + file.getOriginalFilename();
    }

    @GetMapping("/download/{fileName}")
    public String downloadFile(@PathVariable String fileName) throws IOException {
        File file = s3Service.downloadFile(fileName);
        return "File downloaded successfully: " + file.getAbsolutePath();
    }

    @DeleteMapping("/delete/{fileName}")
    public String deleteFile(@PathVariable String fileName) {
        s3Service.deleteFile(fileName);
        return "File deleted successfully: " + fileName;
    }

    @PutMapping("/update")
    public String updateFile(@RequestParam("file") MultipartFile file) throws IOException {
        File convFile = new File(file.getOriginalFilename());
        try (FileOutputStream fos = new FileOutputStream(convFile)) {
            fos.write(file.getBytes());
        }
        s3Service.updateFile(file.getOriginalFilename(), convFile);
        return "File updated successfully: " + file.getOriginalFilename();
    }

    @GetMapping("/read/{fileName}")
    public String readFileContent(@PathVariable String fileName) throws IOException {
        return s3Service.readFileContent(fileName);
    }
}

步骤五：启动Spring Boot应用程序

确保所有配置和代码都正确之后，你可以启动Spring Boot应用程序。你可以使用以下命令来启动应用程序：

mvn spring-boot:run

示例操作

• 上传文件：
  通过POST请求上传文件，示例如下：

  curl -X POST -F "file=@/path/to/your/file.txt" http://localhost:8080/api/s3/upload
  

• 下载文件：
  通过GET请求下载文件，示例如下：

  curl -X GET http://localhost:8080/api/s3/download/file.txt
  

• 删除文件：
  通过DELETE请求删除文件，示例如下：

  curl -X DELETE http://localhost:8080/api/s3/delete/file.txt
  

• 更新文件：
  通过PUT请求更新文件，示例如下：

  curl -X PUT -F "file=@/path/to/your/file.txt" http://localhost:8080/api/s3/update
  

• 读取文件内容：
  通过GET请求读取文件内容，示例如下：

  curl -X GET http://localhost:8080/api/s3/read/file.txt
  

以上