问题
I have the following code for music recognition. I am using intent service to do all the music recognition in the service. I have done all the basic steps like adding all the permissions required and adding the ACRCloud android SDK in the project.
class SongIdentifyService(discoverPresenter : DiscoverPresenter? = null) : IACRCloudListener , IntentService("SongIdentifyService") {
private val callback : SongIdentificationCallback? = discoverPresenter
private val mClient : ACRCloudClient by lazy { ACRCloudClient() }
private val mConfig : ACRCloudConfig by lazy { ACRCloudConfig() }
private var initState : Boolean = false
private var mProcessing : Boolean = false
override fun onHandleIntent(intent: Intent?) {
Log.d("SongIdentifyService", "onHandeIntent called" )
setUpConfig()
addConfigToClient()
if (callback != null) {
startIdentification(callback)
}
}
public fun setUpConfig(){
Log.d("SongIdentifyService", "setupConfig called")
this.mConfig.acrcloudListener = this@SongIdentifyService
this.mConfig.host = "some-host"
this.mConfig.accessKey = "some-accesskey"
this.mConfig.accessSecret = "some-secret"
this.mConfig.protocol = ACRCloudConfig.ACRCloudNetworkProtocol.PROTOCOL_HTTP // PROTOCOL_HTTPS
this.mConfig.reqMode = ACRCloudConfig.ACRCloudRecMode.REC_MODE_REMOTE
}
// Called to start identifying/discovering the song that is currently playing
fun startIdentification(callback: SongIdentificationCallback)
{
Log.d("SongIdentifyService", "startIdentification called")
if(!initState)
{
Log.d("AcrCloudImplementation", "init error")
}
if(!mProcessing) {
mProcessing = true
if (!mClient.startRecognize()) {
mProcessing = false
Log.d("AcrCloudImplementation" , "start error")
}
}
}
// Called to stop identifying/discovering song
fun stopIdentification()
{
Log.d("SongIdentifyService", "stopIdentification called")
if(mProcessing)
{
mClient.stopRecordToRecognize()
}
mProcessing = false
}
fun cancelListeningToIdentifySong()
{
if(mProcessing)
{
mProcessing = false
mClient.cancel()
}
}
fun addConfigToClient(){
Log.d("SongIdentifyService", "addConfigToClient called")
this.initState = this.mClient.initWithConfig(this.mConfig)
if(this.initState)
{
this.mClient.startPreRecord(3000)
}
}
override fun onResult(result: String?) {
Log.d("SongIdentifyService", "onResult called")
Log.d("SongIdentifyService",result)
mClient.cancel()
mProcessing = false
val result = Gson().fromJson(result, SongIdentificationResult :: class.java)
if(result.status.code == 3000)
{
callback!!.onOfflineError()
}
else if(result.status.code == 1001)
{
callback!!.onSongNotFound()
}
else if(result.status.code == 0 )
{
callback!!.onSongFound(MusicDataMapper().convertFromDataModel(result))
//callback!!.onSongFound(Song("", "", ""))
}
else
{
callback!!.onGenericError()
}
}
override fun onVolumeChanged(p0: Double) {
TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
}
interface SongIdentificationCallback {
// Called when the user is offline and music identification failed
fun onOfflineError()
// Called when a generic error occurs and music identification failed
fun onGenericError()
// Called when music identification completed but couldn't identify the song
fun onSongNotFound()
// Called when identification completed and a matching song was found
fun onSongFound(song: Song)
}
}
Now when I am starting the service I am getting the following error:
回答1:
I checked the implementation of the ACRCloudClient and its extends android Activity. Also ACRCloudClient uses shared preferences(that's why I am getting a null pointer exception).
Since keeping a reference to an activity in a service is not a good Idea its best to Implement the above code in the activity. All the implementation of recognizing is being done in a separate thread anyway in the ACRCloudClient class so there is no point of creating another service for that.
来源：https://stackoverflow.com/questions/49705028/acrcloud-integration-to-android-app