Java SpringBoot实现上传文件到AWS S3

简单记录一下在Springboot中上传文件到AWS S3存储服务的代码。

在 application . xml 中添加aws相关配置：

custom:
  aws:
    access-key: CHOBITACCESSKEY
    secret-key: CHOBIT/THISIS006SECRET007Key/dotORG
    bucket: zhyea
    endpoint: www.zhyea.com:80

新建一个 AwsS3Componment 类来执行上传文件操作：

@Component
public class AwsS3Component implements InitializingBean {
 
    @Value("${custom.aws.access-key}")
    private String accessKey;
 
    @Value("${custom.aws.secret-key}")
    private String accessSecret;
 
    @Value("${custom.aws.bucket}")
    private String bucket;
 
    @Value("${custom.aws.endpoint}")
    private String endpoint;
 
    private AmazonS3 client;
 
 
    @Override
    public void afterPropertiesSet() {
        ClientConfiguration config = new ClientConfiguration();
        config.setProtocol(Protocol.HTTP);
        config.disableSocketProxy();
 
        this.client = AmazonS3ClientBuilder
                .standard()
                .withClientConfiguration(config)
                .withCredentials(new AWSStaticCredentialsProvider(new BasicAWSCredentials(accessKey, accessSecret)))
                .withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(endpoint, Regions.CN_NORTH_1.getName()))
                .enablePathStyleAccess()
                .build();
    }
}

因为使用的服务有设置 endpoint ，所以这里需要使用下面这一行完成 endpoint 的设置：

withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(endpoint, Regions.CN_NORTH_1.getName()))

如果不设置 endpoint 就会收到下面这样的报错：

com.amazonaws.services.s3.model.AmazonS3Exception: The AWS Access Key Id you provided does not exist in our records. (Service: Amazon S3; Status Code: 403; Error Code: InvalidAccessKeyId; Request ID: FRDT8N0RAQFNCVDP; S3 Extended Request ID: DemEatwroXry2YN/5lyuMKDmhIi/aIz3QZPmLN0DYHeHU3oGUeOClJBcToz1J1qkcBZBfklRNs8=)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleErrorResponse(AmazonHttpClient.java:1660)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1324)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1074)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:745)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:719)
	at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:701)

异常信息中提示了 AccessKey 无效——虽然我的 AccessKey 是有效的。

在 endpoint 的这行配置中还设置了 region 信息。如果不需要设置 endpoint ，就得补上 region 的配置：

this.client = AmazonS3ClientBuilder
        .standard()
        .withClientConfiguration(config)
        .withCredentials(new AWSStaticCredentialsProvider(new BasicAWSCredentials(accessKey, accessSecret)))
        .withRegion(Regions.CN_NORTH_1) //Region配置
        .enablePathStyleAccess()
        .build();

下面是执行上传的代码：

/**
 * 执行文件上传
 *
 * @param file 要上传的文件的路径
 * @param key  存储文件的路径
 * @return 文件路径
 */
private String upload(File file, String key) {
    client.putObject(new PutObjectRequest(bucket, key, file).withCannedAcl(CannedAccessControlList.PublicRead));
    GeneratePresignedUrlRequest urlRequest = new GeneratePresignedUrlRequest(bucket, key);
    URL url = client.generatePresignedUrl(urlRequest);
    return url.toString();
}

这里是通过 File 实例执行的上传。有时候会需要直接通过文件流执行上传，此时可以使用下面的代码：

private String upload(InputStream input, String key) throws IOException {
    Date expireDate = new Date(System.currentTimeMillis() + TimeUnit.DAYS.toMillis(30));
    ObjectMetadata metadata = new ObjectMetadata();
    metadata.setHttpExpiresDate(expireDate);
    metadata.setContentLength(input.available());
 
    client.putObject(new PutObjectRequest(bucket, key, input, metadata).withCannedAcl(CannedAccessControlList.PublicRead));
    GeneratePresignedUrlRequest urlRequest = new GeneratePresignedUrlRequest(bucket, key);
    URL url = client.generatePresignedUrl(urlRequest);
    return url.toString();
}

注意这里的 setContentLength ( ) 最好配置一下。不设置会在处理的时候给出WARN。根据方法文档也可以看到，如果不设置，在上传的时候就会先在内存中缓存整个信息流来计算文件长度。

大体上就是这样了。

End！