【安卓app开发】kotlin Jetpack Compose框架 | 先用OKhttp下载远程音频文件再使用ExoPlayer播放

dependencies {
    // Jetpack Compose
    implementation "androidx.compose.ui:ui:1.0.0"
    implementation "androidx.compose.material:material:1.0.0"
    implementation "androidx.compose.ui:ui-tooling-preview:1.0.0"

    // OkHttp
    implementation "com.squareup.okhttp3:okhttp:4.9.2"
    
    // ExoPlayer
    implementation 'com.google.android.exoplayer:exoplayer:2.14.1'
}

import android.content.Context
import android.net.Uri
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.launchedEffect
import androidx.compose.ui.tooling.preview.Preview
import com.google.accompanist.permissions.ExperimentalPermissionsApi
import com.google.accompanist.permissions.rememberPermissionState
import com.google.accompanist.permissions.MultiplePermissionsState
import com.google.accompanist.permissions.rememberMultiplePermissionsState
import com.google.android.exoplayer2.ExoPlayer
import com.google.android.exoplayer2.MediaItem
import okhttp3.OkHttpClient
import okhttp3.Request
import java.io.File
import kotlin.concurrent.thread

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MaterialTheme {
                MyApp(this)
            }
        }
    }
}

@Composable
fun MyApp(context: Context) {
    val audioUrl = "https://example.com/path/to/your/audiofile.mp3"
    val downloadedFile = File(context.cacheDir, "downloaded.mp3")

    // Permissions handling (Optional, if your file needs special storage permissions)
    val context = LocalContext.current
    val permissionsState = rememberMultiplePermissionsState(listOf(
        android.Manifest.permission.INTERNET,
        android.Manifest.permission.WRITE_EXTERNAL_STORAGE
    ))
    
    if (permissionsState.allPermissionsGranted) {
        DownloadAndPlayAudio(context, audioUrl, downloadedFile)
    } else {
        permissionsState.launchMultiplePermissionRequest()
    }
}

@Composable
fun DownloadAndPlayAudio(context: Context, url: String, file: File) {
    launchedEffect(url) {
        thread {
            val client = OkHttpClient()
            val request = Request.Builder().url(url).build()
            client.newCall(request).execute().use { response ->
                if (response.isSuccessful) {
                    response.body?.byteStream()?.use { input -> file.outputStream().use { output -> input.copyTo(output) } }
                    playAudio(context, Uri.fromFile(file))
                }
            }
        }
    }

    Text("Downloading and playing...")
}

fun playAudio(context: Context, uri: Uri) {
    val player = ExoPlayer.Builder(context).build()
    val mediaItem = MediaItem.fromUri(uri)
    player.setMediaItem(mediaItem)
    player.prepare()
    player.playWhenReady = true
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    MaterialTheme {
        Text("Hello Android!")
    }
}