mainActivity
public class MainActivity extends AppCompatActivity {
Button button1;
EditText edittext1;
EditText edittext2;
RecyclerView listview1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button1=(Button) findViewById(R.id.button1);
edittext1=(EditText) findViewById(R.id.edittext1);
edittext2=(EditText) findViewById(R.id.edittext2);
ListView listview = (ListView) findViewById(R.id.listview1) ;
final ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1,android.R.id.text1) ;
listview.setAdapter(adapter) ;
DatabaseReference database = FirebaseDatabase.getInstance().getReference();
database.child("message").addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Board board = dataSnapshot.getValue(Board.class); // Board를 가져오고
adapter.add(board.gettitle()); // adapter에 추가합니다.
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
} // message 이하 child의 이벤트를 수신
});
}
public void click1button(View v){
DatabaseReference database = FirebaseDatabase.getInstance().getReference();
Board board=new Board(edittext2.getText().toString(),edittext1.getText().toString());
database.child("message").push().setValue(board);
}
Board
package com.example.myapplication100;
class Board {
String title;
String content;
Board(){}
Board(String title, String content){
this.title=title;
this.content=content;
}
public Object gettitle() {return title;}
public String getContent(){return content;}
}
[오류코드]
E/eglCodecCommon: GoldfishAddressSpaceHostMemoryAllocator: ioctl_ping failed for device_type=5, ret=-1
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myapplication100, PID: 6155
com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.myapplication100.Board
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(com.google.firebase:firebase-database@@19.3.0:435)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.3.0:231)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(com.google.firebase:firebase-database@@19.3.0:79)
at com.google.firebase.database.DataSnapshot.getValue(com.google.firebase:firebase-database@@19.3.0:203)
at com.example.myapplication100.MainActivity$1.onChildAdded(MainActivity.java:74)
at com.google.firebase.database.core.ChildEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.3.0:79)
at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.3.0:63)
at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.3.0:55)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
찾아도 도통 안나와서... 제가 놓친것이 있나요?ㅠ 애뮬레이터를 작동시키면 강제종료됩니다..