Firebase异常无法将字符串转换为类型

Question

我无法解决此错误，有人可以帮我吗？我正在使用Firebase，但是此错误即将出现

  

com.google.firebase.database.DatabaseException：无法转换对象   类型为java.lang.String的类型**

public class riderdashboard extends AppCompatActivity {
    Button btn;
    Button btn2;
    ListView historylistView;
    private DatabaseReference mRef;
    private DatabaseReference mdsRef;
   // private DatabaseReference databaseRevenue;
    List<Jobhstory> jobhstoryList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_riderdashboard);
        mRef=FirebaseDatabase.getInstance().getReference();
        mdsRef=mRef.child("Data");
        Log.i("dta", mdsRef.toString());
        btn = (Button) findViewById(R.id.revenue);
        btn2 = (Button) findViewById(R.id.jobhistory);
        historylistView = (ListView) findViewById(R.id.historylistview);
        jobhstoryList = new ArrayList<>();
btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        mdsRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
               // jobhstoryList.clear();
                for (DataSnapshot revenuesnapshot : dataSnapshot.getChildren()) {
                    Jobhstory jobhstory = revenuesnapshot.getValue(Jobhstory.class);
                   // String time=revenuesnapshot.child("Data").getValue(String.class);
                    Log.i("jobhstory", jobhstory.toString());
                   // Log.i("tetxe",time);
                    jobhstoryList.add(jobhstory);
                }
                Jobhistory adapter = new Jobhistory(riderdashboard.this, jobhstoryList);
                historylistView.setAdapter(adapter);
            }


            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }
});


    }
}

Jobhstory.java此类用于构造函数和getter（）

public class Jobhstory  {
    String dta;
    String tm;
    String earn;

    public Jobhstory(String date, String time, String earn) {
        this.dta = date;
        this.tm = time;
        this.earn = earn;
    }

    public String getDta() {
        return dta;
    }

    public String getTm() {
        return tm;
    }

    public String getEarn() {
        return earn;
    }
}

Jobhistory.java 该类用作arrayAdapter

public class Jobhistory extends ArrayAdapter<Jobhstory>{
    private Activity context;
    private List<Jobhstory> revenue;

    public Jobhistory( Activity context1, List<Jobhstory> revenue) {
        super(context1,R.layout.historylayout,revenue);
        this.context = context1;
        this.revenue = revenue;

    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        LayoutInflater inflater=context.getLayoutInflater();
        View view=inflater.inflate(R.layout.historylayout,null,true);
        TextView textView1=(TextView)view.findViewById(R.id.date);
        TextView textView2=(TextView)view.findViewById(R.id.time);
        TextView textView3=(TextView)view.findViewById(R.id.earn);
        Jobhstory jobhstory=revenue.get(position);
        textView1.setText(jobhstory.getDta());
        textView2.setText(jobhstory.getTm());
        textView3.setText(jobhstory.getEarn());
        return view;

    }
}