Lottie动画资源放到服务器预下载，2021年Android开发突破20k有哪些有效的路径

//资源打包成zip文件放到了服务器上，所以下载下来要解压缩
LottieAnimationUtils.unZip(download.file, parentPath)
downloadCount(true)
}

override fun onError(download: Download, error: Error, throwable: Throwable?) {
if (download.group != groupId) {
return
}
downloadCount(false)
}

private val downloadCount: (Boolean) -> Unit = {
downloaded++
if (downloaded == num) {
callback?.invoke(it)
fetch.removeListener(this)
}
}
}

fun downloadList(pathList: List, priority: Priority = Priority.NORMAL, callback: ((Boolean) -> Unit)? = null) {
val groupId = Random.nextInt()
pathList.filter {
//本地文件不存在的才下载
!File(parentPath + File.separator + i

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t).exists()
}.flatMap { path ->
arrayListOf(Request(“ F i l e D o w n l o a d C o n s t a n t . B a s e C o n f i g . G I F T P A T H / {FileDownloadConstant.BaseConfig.GIFT_PATH}/ FileDownloadConstant.BaseConfig.GIFTP​ATH/path” + “.zip”, parentPath + “/” + path + “.zip”).also {
it.groupId = groupId
it.priority = priority
})
}.apply {
if (size == 0) {
callback?.invoke(true)
return@apply
}
fetch.addListener(DownloadListener(groupId, size, callback)).enqueue(this)
}
}

/**

• 下载单个文件
  */
  fun download(path: String, callback: ((Boolean) -> Unit)? = null) {
  if (File(“ p a r e n t P a t h / parentPath/ parentPath/path” + “.zip”).exists()) {
  callback?.invoke(true)
  return
  }
  val groupId = Random.nextInt()
  fetch.addListener(DownloadListener(groupId, 1, callback)).enqueue(Request(“ F i l e D o w n l o a d C o n s t a n t . B a s e C o n f i g . G I F T P A T H / {FileDownloadConstant.BaseConfig.GIFT_PATH}/ FileDownloadConstant.BaseConfig.GIFTP​ATH/path” + “.zip”, “ p a r e n t P a t h / parentPath/ parentPath/path.zip”).also { it.groupId = groupId })
  }
  }

下载框架使用的是一个开源的，名字叫Fetch

在启动页的onCreate方法中，调用：

FileDownloadUtil.INSTANCE.downloadList(FileDownloadConstant.INSTANCE.getGiftList(), Priority.NORMAL,null);

就开始下载资源了

那么怎么使用Lottie框架加载文件夹中的动画资源呢？直接上代码

object LottieAnimationUtils {
//lottie加载本地资源的核心方法
fun loadLottie(lottieAnimationView: LottieAnimationView,imagePath:String,dataPath : String,giftName:String):FileInputStream?{
lottieAnimationView.setCacheComposition(false)
val imageFiles = File(imagePath)
val jsonFile = File(dataPath)
var fis:FileInputStream? = null
//资源中只有json文件的时候走这里
if (!imageFiles.exists()) {
if (jsonFile.exists()) {
fis = FileInputStream(jsonFile)
try {
lottieAnimationView.setImageAssetDelegate(null)
}catch (e : Exception) {

}
LottieComposition.Factory.fromInputStream(fis) {
lottieAnimationView.postDelayed(Runnable {
lottieAnimationView.visibility = View.VISIBLE
},200)
it?.let {
it1 -> lottieAnimationView.setComposition(it1)
}
lottieAnimationView.playAnimation()
}
}else {
FileDownloadUtil.download(giftName)
}
return fis
}
//资源中有imges和json的走这里
try {
fis = FileInputStream(jsonFile)
val absolutePath = imageFiles.absolutePath
lottieAnimationView.setImageAssetDelegate() {
val opts = BitmapFactory.Options()
opts.inScaled = true
var bitmap: Bitmap? = null
bitmap = BitmapFactory.decodeFile(absolutePath + File.separator + it.fileName, opts)
bitmap
}
LottieComposition.Factory.fromInputStream(fis) {
lottieAnimationView.postDelayed(Runnable {
lottieAnimationView.visibility = View.VISIBLE
},200)
it?.let { it1 -> lottieAnimationView.setComposition(it1) }
lottieAnimationView.playAnimation()
}
return fis
} catch (e: Exception) {

}
return null
}

//这个是解压缩的方法，解压缩的工具类可以从网上找一个
fun unZip(imagePath: String,destPath:String) {
val file = File(imagePath)
val destFile = File(destPath)
if (!destFile.exists()) {
destFile.mkdir()
}
if (!file.exists()) return
ZipUtils.unzipFile(file,destFile)
}

//辅助类，不重要
fun inputStreamClose(fis:FileInputStream?) {
if (fis != null) {
try {
fis.close()
} catch (e: IOException) {
e.printStackTrace()
}
}
}
//辅助类，不重要
fun getGiftFileName(giftId:Int):String {
if (giftId > FileDownloadConstant.giftList.size){
return “”
}