dependencies {
    def aws_version = "2.16.+"
    implementation "com.amazonaws:aws-android-sdk-s3:$aws_version"
    implementation ("com.amazonaws:aws-android-sdk-mobile-client:$aws_version") { transitive = true }
    public void downloadFileByKey(String key) throws JSONException {
        JSONObject jsonConfig = new JSONObject();
        JSONObject s3TransferUtility = new JSONObject();
        jsonConfig.putOpt("S3TransferUtility", s3TransferUtility);
        s3TransferUtility.put("Region", "服务端请求来的region");
        s3TransferUtility.put("Bucket", "服务端请求来bucket");
        AWSSessionCredentials credentials = new AWSSessionCredentials() {
            @Override
            public String getSessionToken() {
                return "服务端请求过来的SessionToken";
            @Override
            public String getAWSAccessKeyId() {
                return "服务端请求来的AccessKey";
            @Override
            public String getAWSSecretKey() {
                return "服务端请求来的SecretKey";
        AWSConfiguration configuration = new AWSConfiguration(jsonConfig);
        TransferUtility utility = TransferUtility.builder()
                .context(this)
                .s3Client(new AmazonS3Client(credentials))
                .awsConfiguration(configuration)
                .build();
        File file = new File(Environment.getExternalStorageDirectory().getPath() + "/test44.png");
        TransferObserver observer = utility.download(key, file);
        observer.setTransferListener(new TransferListener() {
            @Override
            public void onStateChanged(int i, TransferState transferState) {
                if (transferState == TransferState.COMPLETED) {
                    //下载完成了
            @Override
            public void onProgressChanged(int i, long l, long l1) {
            @Override
            public void onError(int i, Exception e) {
                //下载出错
以上是下载文件，上传文件类似：
TransferObserver observer = utility.upload(key, file);