Android通过okhttp下载文件(本文案例下载mp4到本地，并更新到相册)

使用步骤分为两步

okhttp3__1">第一步导入 okhttp3 依赖

第二步调用本文提供的 utils

第一步这里不做说明了，直接提供第二步复制即用

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DownloadUtil 中 download 为下载文件参数说明

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这里主要看你把 destFileName 下载文件名称定义为什么后缀，比如我定义为 .mp4 下载后就是 mp4 格式

这里 destFileDir 下载目录要说一下，如果没有开启存储权限或者使用了系统默认路径就会报错比如 /0 文件一类的错误，怎么使用可以参考 open failed: ENOENT (No such file or directory) 解决办法

DownloadUtil 中 saveVideoToAlbum 为将下载好的视频更新到手机图库中，原来的放式已经随着安全性提高不适用了，这里基本就是复制出一份更新到系统层的文件夹

源码

DownloadUtil.download(mVideoUrl,getUrlPath(),"sing示例名称${System.currentTimeMillis()}.mp4",object : DownloadUtil.OnDownloadListener{override fun onDownloadSuccess(file: File?) {"下载成功".toast()//更新视频到相册DownloadUtil.saveVideoToAlbum(this@MoreActivity,file?.absolutePath)Log.e("视频下载", "下载成功: ${file?.absolutePath}")}override fun onDownloading(progress: Int) {Log.e("视频下载", "下载进度:${progress}")}override fun onDownloadFailed(e: Exception?) {LoadingSingDialog.dismiss()Log.e("视频下载", "下载失败:${e?.printStackTrace()}")}})

DownloadUtil

object DownloadUtil {private var okHttpClient: OkHttpClient? = null/*** @param url          下载连接* @param destFileDir  下载的文件储存目录* @param destFileName 下载文件名称* @param listener     下载监听*/fun download(url: String, destFileDir: String, destFileName: String, listener: OnDownloadListener) {if (url == null || url == ""){return}if (okHttpClient == null){okHttpClient = OkHttpClient()}val request: Request = Request.Builder().url(url).build()okHttpClient!!.newCall(request).enqueue(object : Callback {override fun onFailure(call: Call, e: IOException) {// 下载失败监听回调listener.onDownloadFailed(e)}@Throws(IOException::class)override fun onResponse(call: Call, response: Response) {if (response.body != null) {var inputStream: InputStream? = nullval buf = ByteArray(2048)var len = 0var fos: FileOutputStream? = null// 储存下载文件的目录val dir = File(destFileDir)if (!dir.exists()) {dir.mkdirs()}val file = File(dir, destFileName)try {inputStream = response.body!!.byteStream()val total: Long = response.body!!.contentLength()fos = FileOutputStream(file)var sum: Long = 0while (inputStream.read(buf).also { len = it } != -1) {fos.write(buf, 0, len)sum += len.toLong()val progress = (sum * 1.0f / total * 100).toInt()// 下载中更新进度条listener.onDownloading(progress)}fos.flush()// 下载完成listener.onDownloadSuccess(file)} catch (e: Exception) {listener.onDownloadFailed(e)} finally {try {inputStream?.close()} catch (e: IOException) {listener.onDownloadFailed(e)}try {fos?.close()} catch (e: IOException) {listener.onDownloadFailed(e)}}}else{listener.onDownloadFailed(IOException("接口失败"))}}})}interface OnDownloadListener {/*** @param file 下载成功后的文件*/fun onDownloadSuccess(file: File?)/*** @param progress 下载进度*/fun onDownloading(progress: Int)/*** @param e 下载异常信息*/fun onDownloadFailed(e: Exception?)}/*** 将视频保存到系统相册*/fun saveVideoToAlbum(context: Context, videoFile: String?): Boolean {if (videoFile == null || videoFile == ""){return false}return if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {saveVideoToAlbumBeforeQ(context, videoFile)} else {saveVideoToAlbumAfterQ(context, videoFile)}}private fun saveVideoToAlbumAfterQ(context: Context, videoFile: String): Boolean {return try {val contentResolver = context.contentResolverval tempFile = File(videoFile)val contentValues = getVideoContentValues(context, tempFile, System.currentTimeMillis())val uri =contentResolver.insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, contentValues)copyFileAfterQ(context, contentResolver, tempFile, uri)contentValues.clear()contentValues.put(MediaStore.MediaColumns.IS_PENDING, 0)context.contentResolver.update(uri!!, contentValues, null, null)context.sendBroadcast(Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri))true} catch (e: java.lang.Exception) {e.printStackTrace()false}}private fun saveVideoToAlbumBeforeQ(context: Context, videoFile: String): Boolean {val picDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)val tempFile = File(videoFile)val destFile = File(picDir, context.packageName + File.separator + tempFile.name)var ins: FileInputStream? = nullvar ous: BufferedOutputStream? = nullreturn try {ins = FileInputStream(tempFile)ous = BufferedOutputStream(FileOutputStream(destFile))var nread = 0Lval buf = ByteArray(1024)var n: Intwhile (ins.read(buf).also { n = it } > 0) {ous.write(buf, 0, n)nread += n.toLong()}MediaScannerConnection.scanFile(context, arrayOf(destFile.absolutePath), arrayOf("video/*")) { path: String?, uri: Uri? -> }true} catch (e: java.lang.Exception) {e.printStackTrace()false} finally {try {ins?.close()ous?.close()} catch (e: IOException) {e.printStackTrace()}}}@Throws(IOException::class)private fun copyFileAfterQ(context: Context,localContentResolver: ContentResolver,tempFile: File,localUri: Uri?) {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q &&context.applicationInfo.targetSdkVersion >= Build.VERSION_CODES.Q) {//拷贝文件到相册的uri,android10及以上得这么干，否则不会显示。可以参考ScreenMediaRecorder的save方法val os = localContentResolver.openOutputStream(localUri!!)Files.copy(tempFile.toPath(), os)os!!.close()tempFile.delete()}}/*** 获取视频的contentValue*/private fun getVideoContentValues(context: Context, paramFile: File, timestamp: Long): ContentValues {val localContentValues = ContentValues()if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {localContentValues.put(MediaStore.Video.Media.RELATIVE_PATH, Environment.DIRECTORY_DCIM+ File.separator + context.packageName)}localContentValues.put(MediaStore.Video.Media.TITLE, paramFile.name)localContentValues.put(MediaStore.Video.Media.DISPLAY_NAME, paramFile.name)localContentValues.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4")localContentValues.put(MediaStore.Video.Media.DATE_TAKEN, timestamp)localContentValues.put(MediaStore.Video.Media.DATE_MODIFIED, timestamp)localContentValues.put(MediaStore.Video.Media.DATE_ADDED, timestamp)localContentValues.put(MediaStore.Video.Media.SIZE, paramFile.length())return localContentValues}}