我在构建应用程序时没有遇到任何错误，但当应用程序最终启动时，它在从JsonArrayRequest()函数获得响应后立即崩溃。
这些是我的日志：logcat 1logcat 2显示器

FATAL EXCEPTION: main
Process: com.example.scoremusplayer, PID: 19239
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object 
at android.content.ContextWrapper.getApplicationContext(ContextWrapper.java:122)
at com.bumptech.glide.Glide.get(Glide.java:128)
at com.bumptech.glide.Glide.getRetriever (Glide.java:510)
at com.bumptech.glide.Glide.with(Glide.java:564)
at com.example.scoremusplayer.scoreExplore.adapter.AdapterForScoreListForAllScoreFragmentForRecyclerView.onBindViewHolder 
at com.example.scoremusplayer.scoreExplore.adapter.AdapterForScoreListForAllScoreFragmentForRecyclerView.onBindViewHolder
at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder (RecyclerView.java:7065)
at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder (RecyclerView.java:7107)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline (RecyclerView.java:6012)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline (RecyclerView.java:6279)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition (RecyclerView.java:6118)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition (RecyclerView.java:6114)
at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2303)
at androidx.recyclerview.widget.GridLayoutManager.LayoutChunk (GridLayoutManager.java:561)
at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)

以下是片段中的代码：

class AllScoresFragment : Fragment() {

    companion object {
        lateinit var tempList : ArrayList<Score>
        fun newInstance() = AllScoresFragment()
    }

    private lateinit var binding: FragmentAllScoresBinding
    private lateinit var viewModel: AllScoresViewModel
    private lateinit var progressDialog : ProgressDialog

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        binding = FragmentAllScoresBinding.inflate(inflater)
        return binding.root
//        return inflater.inflate(R.layout.fragment_all_scores, container, false)
    }

    @Deprecated("Deprecated in Java")
    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)

        viewModel = ViewModelProvider(this)[AllScoresViewModel::class.java]

        binding.include.recyclerViewForScoreContent.setHasFixedSize(true)
        binding.include.recyclerViewForScoreContent.layoutManager = GridLayoutManager(context, 3)

        retrieveTwo()

        binding.swipeToRefresh.setOnRefreshListener {
            retrieveTwo()
            binding.swipeToRefresh.isRefreshing = false
        }
    }

我可以感觉到问题是来自retrieveTwo()函数中的JsonArrayRequest得到响应后发生的事情，但我似乎不知道我在那里做错了什么。

以下是retrieveTwo()函数：

fun retrieveTwo() {
    tempList = ArrayList()
    progressDialog = ProgressDialog(context)
    progressDialog.setMessage("Loading...")
    progressDialog.show()


    val pdfSiteUrl = "https://..."

    // Get a RequestQueue
    AllScoresFragment().context?.let { MySingleton.getInstance(it).requestQueue }

    val jsonArrayRequest = JsonArrayRequest(
        Request.Method.GET, pdfSiteUrl, null,
        { response ->
            
            //Toast the response to know if response is actually gotten
            Toast.makeText(context, response.toString(), Toast.LENGTH_LONG).show()

            var jo : JSONObject

            try {
                for (i in 0 until response.length()){
                    jo = response.getJSONObject(i)
                    val id = jo.getInt("id")
                    val name:String = jo.getString("name")
                    val composer:String = jo.getString("composer")
                    val style:String = jo.getString("style")
                    val theme:String = jo.getString("theme")
                    val album:String = jo.getString("album")
                    val lang:String = jo.getString("lang")
                    val thumbnailUrl:String = jo.getString("thumbnail_url")
                    val pdfUrl: String = jo.getString("pdf_url")

                    val score = Score(
                        id = id,
                        name = name,
                        composer = composer,
                        style = style,
                        theme = theme,
                        album = album,
                        lang = lang,
                        thumbnail_url = pdfSiteUrl + thumbnailUrl,
                        pdf_url = pdfSiteUrl + pdfUrl
                    )

                    tempList.add(score)

                    val adapter =
                        context?.let {
                            AdapterForScoreListForAllScoreFragmentForRecyclerView(it,
                                tempList) }

                    binding.include.recyclerViewForScoreContent.adapter = adapter

                    progressDialog.hide()

                }

            } catch (e : JSONException){
                Toast.makeText(context, e.message, Toast.LENGTH_LONG).show()
                progressDialog.hide()
            }

        },
        { error ->
            Toast.makeText(context,
                error.message,
                Toast.LENGTH_SHORT)
                .show()
            progressDialog.hide()
        }
    )

    // Access the RequestQueue through my singleton class.
    context?.let { MySingleton.getInstance(it).addToRequestQueue(jsonArrayRequest) }
}

以下是我的Recyclerview适配器的外观：

class AdapterForScoreListForAllScoreFragmentForRecyclerView(
    private val context: Context,
    private val scoreList: ArrayList<Score>
) : RecyclerView.Adapter<AdapterForScoreListForAllScoreFragmentForRecyclerView.ViewHolder>() {
    class ViewHolder(binding: ScoreListForRecycleBinding) : RecyclerView.ViewHolder(binding.root){
        val pdfThumbnailImage = binding.thumbnailForScore
        val songTitle = binding.scoreTitleNameOfAllScoresFragment
        val composerName = binding.nameOfComposerForAllScoresFragment
        val genre = binding.styleForAllScoresFragment

        //val for root
        val root = binding.root

    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int)
    : ViewHolder {
        val layoutInflater = LayoutInflater.from(parent.context)
        val scoreList = ScoreListForRecycleBinding.inflate(layoutInflater, parent, false)
        return ViewHolder(scoreList)
    }

    override fun getItemCount(): Int {
        return scoreList.size
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
       
        val scoreName = scoreList[position].name
        val scoreComposer = scoreList[position].composer
        val genre = scoreList[position].style
        val pdfUrl = scoreList[position].pdf_url
        val thumbnailImage = scoreList[position].thumbnail_url

        holder.songTitle.text = scoreName
        holder.composerName.text = scoreComposer
        holder.genre.text = genre

        if (pdfUrl.isNotEmpty()){
            Glide
                .with(FragmentActivity())
                .load(thumbnailImage)
                .placeholder(R.drawable.scoremus_icon_slash)
                .into(holder.pdfThumbnailImage)
        }


        holder.root.setOnClickListener {
            holder.root.isLongClickable = true
            Toast.makeText(
                context,
                "opening \"${scoreName.uppercase()} composed by $scoreComposer\"...",
                Toast.LENGTH_SHORT)
                .show()

            val intent = Intent(context, PdfActivity::class.java)
            intent.putExtra("index", position)
            intent.putExtra("pdfPath", scoreList[position].pdf_url)
            ContextCompat.startActivity(context, intent, null)
        }
    }

}

帮帮我
这就是我想做的
1.从https源请求json数组
1.获取json数组中每个元素的json对象
1.在回收视图中显示对象
但是我的应用程序在得到json数组的响应后崩溃了