将多个图像(近100张)从Android上传到Amazon S3? [英] Upload multiple images(nearly 100) from Android to Amazon S3?

问题描述

我正在尝试将多个图像上传到亚马逊s3存储桶.我尝试上传的图像大小各接近300KB.我正在使用循环上传图像.但是，与ios相比，它需要花费更多时间.我正在使用以下代码将图像上传到S3.

I am trying to upload multiple image to amazon s3 bucket. The size of the images which i am trying to upload is nearly 300KB each. I am using loop to upload the images. But it's taking more time compared to ios. I am using the below code to upload the images to S3.

 val uploadObserver = transferUtility!!.upload(bucketname,
                    , "img_$timeStamp.jpg", File(fileUri.path!!),
                    md, CannedAccessControlList.PublicRead)

            uploadObserver.setTransferListener(object : TransferListener {
                override fun onStateChanged(id: Int, state: TransferState) {
                    if (TransferState.COMPLETED == state) {
                     
                    } else if (TransferState.FAILED == state) {
                  
                    }
                }

                override fun onProgressChanged(id: Int, bytesCurrent: Long, bytesTotal: Long) {
                  
                }

                override fun onError(id: Int, ex: Exception) {
                
                }
            })
        }

请帮助我，如何提高上传速度.

Please help me, how to increase the speed of upload.

推荐答案

使用 RxJava 和 RxAndroid ，您可以一次执行多个异步任务. zip 操作将所有任务绑定为一个任务.您的案例的示例代码如下:

Using RxJava and RxAndroid you can do multiple async task at a time. zip operate binds all task into one task. Sample code for your case is as following:

fun uploadTask(bucketname: String, timeStamp: Long, md: Any, uriList: List<Uri>) {
    
    val singles = mutableListOf<Single<String>>()
    uriList.forEach {
        singles.add(upload(bucketname, timeStamp, it, md).subscribeOn(Schedulers.io()))
    }
    val disposable = Single.zip(singles) {
        // If all request emits success response, then it will bind all emitted
        // object (in this example String) into an Array and you will get callback here.
        // You can change your final response here. In this can I am appending all strings
        // to a string.
        var finalString = ""
        it.forEach {  responseString ->
            finalString += responseString
        }
        finalString
    }
            .subscribe({
                // you will get final response here.
            }, {
                // If any one request failed and emits error all task will be stopped and error
                // will be thrown here.
                it.printStackTrace()
            })
    
}

和upload()方法可以如下:

fun upload(bucketname: String, timeStamp: Long, fileUri: Uri, md: Any): Single<String> {
    return Single.create<String> { emitter ->  // You can change String to anything you want to emmit

        val uploadObserver = transferUtility!!.upload(bucketname,
                , "img_$timeStamp.jpg", File(fileUri.path!!),
                md, CannedAccessControlList.PublicRead)

        uploadObserver.setTransferListener(object : TransferListener {
            override fun onStateChanged(id: Int, state: TransferState) {
                if (TransferState.COMPLETED == state) {
                    emitter.onSuccess("COMPLETED")  // Emmit your object here
                } else if (TransferState.FAILED == state) {
                    emitter.onSuccess("FAILED")
                }
            }
    
            override fun onProgressChanged(id: Int, bytesCurrent: Long, bytesTotal: Long) {
            
            }
    
            override fun onError(id: Int, ex: Exception) {
                emitter.onError(ex)
            }
        })
    }
}

请记住，如果任何上传请求失败，则所有其他任务都将停止.如果要继续，则必须使用onErrorResumeNext()运算符.

Just keep in mind, if any upload request is failed, all other task will be stopped. If you want to continue you have to use onErrorResumeNext() operator in that case.

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