Kotlin Firebase:Can'；t将java.lang.String类型的对象转换为com.example.Model.perizinan类型

我正在尝试将数据从Firebase加载到RecyclerView，我需要将数据从Firebase加载到ArrayList，但我得到以下错误：

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.Model.perizinan

class perizinan(val imageUrl:String, val namakegiatan:String, val keterangan:String, val waktuKegiatan:String, val presensiIzin:String, val tanggalkegiatan:String)
class izin(val perizinan:List<perizinan>)

fun readFirebaseDatabase(){

    val ref= FirebaseDatabase.getInstance().getReference("Admin")
    ref.addValueEventListener(object: ValueEventListener {

        override fun onCancelled(p0: DatabaseError) {
            Log.e("AdminActivity","cancelled")
        }

        override fun onDataChange(p0: DataSnapshot) {
            val uid = FirebaseAuth.getInstance().uid

            p0.child(uid!!).children.forEach{

                it.children.forEach{

                val posts = ArrayList<perizinan>()

                for (snapshot in it.children) {
                    val post = snapshot.getValue(perizinan::class.java)
                    posts.add(post!!)
                }

                    RecyclerViewAdmin.layoutManager = LinearLayoutManager(this@AdminActivity)
                    RecyclerViewAdmin.adapter = adminAdapter(izin(posts), this@AdminActivity)

                }
            }


        }
    })

}

这是我的课：

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.Model.perizinan

class perizinan(val imageUrl:String, val namakegiatan:String, val keterangan:String, val waktuKegiatan:String, val presensiIzin:String, val tanggalkegiatan:String)
class izin(val perizinan:List<perizinan>)

fun readFirebaseDatabase(){

    val ref= FirebaseDatabase.getInstance().getReference("Admin")
    ref.addValueEventListener(object: ValueEventListener {

        override fun onCancelled(p0: DatabaseError) {
            Log.e("AdminActivity","cancelled")
        }

        override fun onDataChange(p0: DataSnapshot) {
            val uid = FirebaseAuth.getInstance().uid

            p0.child(uid!!).children.forEach{

                it.children.forEach{

                val posts = ArrayList<perizinan>()

                for (snapshot in it.children) {
                    val post = snapshot.getValue(perizinan::class.java)
                    posts.add(post!!)
                }

                    RecyclerViewAdmin.layoutManager = LinearLayoutManager(this@AdminActivity)
                    RecyclerViewAdmin.adapter = adminAdapter(izin(posts), this@AdminActivity)

                }
            }


        }
    })

}

class perizinan（val-imageUrl:String，val-namakegiatan:String，val-keteragan:String，val-waktuKegiatan:String，val-presensisizin:String，val-tanggalkegiatan:String）
izin类（val perizinan:列表）

这是我的代码：

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.Model.perizinan

class perizinan(val imageUrl:String, val namakegiatan:String, val keterangan:String, val waktuKegiatan:String, val presensiIzin:String, val tanggalkegiatan:String)
class izin(val perizinan:List<perizinan>)

fun readFirebaseDatabase(){

    val ref= FirebaseDatabase.getInstance().getReference("Admin")
    ref.addValueEventListener(object: ValueEventListener {

        override fun onCancelled(p0: DatabaseError) {
            Log.e("AdminActivity","cancelled")
        }

        override fun onDataChange(p0: DataSnapshot) {
            val uid = FirebaseAuth.getInstance().uid

            p0.child(uid!!).children.forEach{

                it.children.forEach{

                val posts = ArrayList<perizinan>()

                for (snapshot in it.children) {
                    val post = snapshot.getValue(perizinan::class.java)
                    posts.add(post!!)
                }

                    RecyclerViewAdmin.layoutManager = LinearLayoutManager(this@AdminActivity)
                    RecyclerViewAdmin.adapter = adminAdapter(izin(posts), this@AdminActivity)

                }
            }


        }
    })

}

fun readFirebaseDatabase（）{
val ref=FirebaseDatabase.getInstance（）.getReference（“管理员”）
ref.addValueEventListener（对象：ValueEventListener{
已取消覆盖乐趣（p0:DatabaseError）{
Log.e（“AdminActivity”、“已取消”）
}
覆盖数据更改（p0:DataSnapshot）{
val uid=FirebaseAuth.getInstance（）.uid
p0.child（uid！！）.children.forEach{
它，孩子们{
val posts=ArrayList（）
用于（it.children中的快照）{
val post=snapshot.getValue（perizinan:：class.java）
添加（post！！）
}
RecycleServiceAdmin.layoutManager=LinearLayoutManager(this@AdminActivity)
recycleServiceAdmin.adapter=adminAdapter（izin（posts），this@AdminActivity)
}
}
}
})
}

下面是我的数据库结构：

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.Model.perizinan

class perizinan(val imageUrl:String, val namakegiatan:String, val keterangan:String, val waktuKegiatan:String, val presensiIzin:String, val tanggalkegiatan:String)
class izin(val perizinan:List<perizinan>)

fun readFirebaseDatabase(){

    val ref= FirebaseDatabase.getInstance().getReference("Admin")
    ref.addValueEventListener(object: ValueEventListener {

        override fun onCancelled(p0: DatabaseError) {
            Log.e("AdminActivity","cancelled")
        }

        override fun onDataChange(p0: DataSnapshot) {
            val uid = FirebaseAuth.getInstance().uid

            p0.child(uid!!).children.forEach{

                it.children.forEach{

                val posts = ArrayList<perizinan>()

                for (snapshot in it.children) {
                    val post = snapshot.getValue(perizinan::class.java)
                    posts.add(post!!)
                }

                    RecyclerViewAdmin.layoutManager = LinearLayoutManager(this@AdminActivity)
                    RecyclerViewAdmin.adapter = adminAdapter(izin(posts), this@AdminActivity)

                }
            }


        }
    })

}

---

您之所以会出现此错误，是因为您在尝试从数据库获取

perizinan

对象时使用了错误的引用。要解决此问题，请更改以下代码行：

val ref= FirebaseDatabase.getInstance().getReference("Admin")

到

及

到

---

Admin

节点下的第一个uid是登录用户的

uid

，第二个和第三个uid是什么的id？第二个uid来自消息发送者，第三个是消息uid，这类似于聊天应用程序，所以您想在登录用户id或消息uid下获取所有帖子？在第一种情况下，这仅仅是一个。在消息uid下，请注意，但我不能向recyclerview显示，哈哈哈，解决这个问题会带来另一个问题：vYa，这一直在发生。这听起来像是一个新问题，基本上应该被视为另一个问题，因此请使用发布另一个新问题，以便我和其他Firebase开发人员可以帮助您。