댓글 불러오기 파트 진행 중인데 앱이 다운되네요 ㅠㅠ

댓글 불러오기 부분 하고 있는데

2022-09-18 18:50:08.110 7539-7539/com.example.mysololife E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.mysololife, PID: 7539

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.mysololife.comment.CommentModel

at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(CustomClassMapper.java:436)

at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:232)

at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(CustomClassMapper.java:80)

at com.google.firebase.database.DataSnapshot.getValue(DataSnapshot.java:203)

at com.example.mysololife.board.BoardInsideActivity$getCommentData$postListener$1.onDataChange(BoardInsideActivity.kt:77)

at com.google.firebase.database.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:75)

at com.google.firebase.database.core.view.DataEvent.fire(DataEvent.java:63)

at com.google.firebase.database.core.view.EventRaiser$1.run(EventRaiser.java:55)

at android.os.Handler.handleCallback(Handler.java:942)

at android.os.Handler.dispatchMessage(Handler.java:99)

at android.os.Looper.loopOnce(Looper.java:201)

at android.os.Looper.loop(Looper.java:288)

at android.app.ActivityThread.main(ActivityThread.java:7898)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

이러한 오류 메시지 뜨면서 앱이 죽습니다

코드는 board inside 부분은

package com.example.mysololife.board

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.widget.Button
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.core.view.isVisible
import androidx.databinding.DataBindingUtil
import com.bumptech.glide.Glide
import com.example.mysololife.R
import com.example.mysololife.comment.CommentLVAdapter
import com.example.mysololife.comment.CommentModel
import com.example.mysololife.databinding.ActivityBoardInsideBinding
import com.example.mysololife.utils.FBAuth
import com.example.mysololife.utils.FBRef
import com.google.android.gms.tasks.OnCompleteListener
import com.google.firebase.database.DataSnapshot
import com.google.firebase.database.DatabaseError
import com.google.firebase.database.ValueEventListener
import com.google.firebase.ktx.Firebase
import com.google.firebase.storage.ktx.storage
import java.lang.Exception

class BoardInsideActivity : AppCompatActivity() {
    private val commentDataList = mutableListOf<CommentModel>()

    private lateinit var binding : ActivityBoardInsideBinding

    private lateinit var key : String

    private lateinit var commentAdapter : CommentLVAdapter


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this,R.layout.activity_board_inside)

//        val title = intent.getStringExtra("title").toString()
//        val content = intent.getStringExtra("content").toString()
//        val time = intent.getStringExtra("time").toString()

//        binding.titleArea.text = title
//        binding.textArea.text = content
//        binding.timeArea.text = time

        key = intent.getStringExtra("key").toString()
        getBoardData(key)
        getImageData(key)

        binding.boardSetting.setOnClickListener {
            showDialog()
        }

        binding.commentBtn.setOnClickListener {
            insertComment(key)
        }


        getCommentData(key)

        commentAdapter = CommentLVAdapter(commentDataList)
        binding.commentLV.adapter = commentAdapter
    }

    fun getCommentData(key: String){
        val postListener = object : ValueEventListener {
            override fun onDataChange(dataSnapshot: DataSnapshot) {

                commentDataList.clear()

                for (dataModel in dataSnapshot.children) {

                    val item = dataModel.getValue(CommentModel::class.java)
                    commentDataList.add(item!!)
                }
                commentAdapter.notifyDataSetChanged()
            }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("TalkFragment", "loadPost:onCancelled", databaseError.toException())
            }
        }
        FBRef.commentRef.child(key).addValueEventListener(postListener)
    }

    fun insertComment(key: String){
        FBRef.commentRef
            .child(key)
            .push()
            .setValue(CommentModel(
                binding.commentArea.text.toString(),
                FBAuth.getTime()
            )
            )

        Toast.makeText(this,"댓글 입력 완료",Toast.LENGTH_LONG).show()
        binding.commentArea.setText("")
    }

    private fun showDialog(){
        val mDialogView = LayoutInflater.from(this).inflate(R.layout.custom_dialog,null)
        val mBuilder = AlertDialog.Builder(this)
            .setView(mDialogView)
            .setTitle("게시글 수정/삭제")

        val alertDialog = mBuilder.show()
        alertDialog.findViewById<Button>(R.id.editBtn)?.setOnClickListener {
            val intent = Intent(this,BoardEditActivity::class.java)
            intent.putExtra("key",key)
            startActivity(intent)
        }
        alertDialog.findViewById<Button>(R.id.removeBtn)?.setOnClickListener {
            FBRef.boardRef.child(key).removeValue()
            Toast.makeText(this,"삭제 완료",Toast.LENGTH_LONG).show()
            finish()
        }

    }

    private fun getImageData(key:String){

        val storageReference = Firebase.storage.reference.child(key)



        val imageViewFB = binding.getImageArea

        storageReference.downloadUrl.addOnCompleteListener(OnCompleteListener { task ->
            if (task.isSuccessful) {
                Glide.with(this)
                    .load(task.result)
                    .into(imageViewFB)
            }
            else {
                binding.getImageArea.isVisible = false
            }
        })

    }

    private fun getBoardData(key: String){
        val postListener = object : ValueEventListener {
            override fun onDataChange(dataSnapshot: DataSnapshot) {

                try {
                    val dataModel = dataSnapshot.getValue(BoardModel::class.java)

                    binding.titleArea.text = dataModel!!.title
                    binding.textArea.text = dataModel!!.content
                    binding.timeArea.text = dataModel!!.time

                    val myUid = FBAuth.getUid()
                    val writeUid = dataModel.uid

                    if (myUid == writeUid){
                        binding.boardSetting.isVisible = true
                    }
                    else {

                    }


                }
                catch (e: Exception){

                }



            }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("TalkFragment", "loadPost:onCancelled", databaseError.toException())
            }
        }
        FBRef.boardRef.child(key).addValueEventListener(postListener)
    }
}

이렇게 짰습니다 오류메세지가 가르키는 부분이

    for (dataModel in dataSnapshot.children) {

    이쪽-->    val item = dataModel.getValue(CommentModel::class.java)
        commentDataList.add(item!!)
    }
    commentAdapter.notifyDataSetChanged()
}

이던데 뭐가 문제일까요?

추가로 commentLVAdapter는

package com.example.mysololife.comment

import android.graphics.Color
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.BaseAdapter
import android.widget.LinearLayout
import android.widget.TextView
import com.example.mysololife.R
import com.example.mysololife.utils.FBAuth

class CommentLVAdapter(val commentList : MutableList<CommentModel>) : BaseAdapter () {
    override fun getCount(): Int {
        return commentList.size
    }

    override fun getItem(p0: Int): Any {
        return commentList[p0]
    }

    override fun getItemId(p0: Int): Long {
        return p0.toLong()
    }

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
        var view = convertView

        if (view == null) {
            view = LayoutInflater.from(parent?.context)
                .inflate(R.layout.board_list_item, parent, false)
        }
        val title = view?.findViewById<TextView>(R.id.titleArea)

        val time = view?.findViewById<TextView>(R.id.timeArea)


        title!!.text = commentList[position].commentTitle
        time!!.text = commentList[position].commentCreatedTime

        return view!!
    }
}

이렇게 모델은

package com.example.mysololife.comment

data class CommentModel (
    val commentTitle : String = "",
    val commentCreatedTime : String = ""
)

이렇게 했습니다