Android Firebase 실시간 데이터베이스

Question

firebase 실시간 데이터베이스를 사용하는 모든 기기의 데이터를 업데이트하고 싶습니다. 저는 앱을 만들었지 만 데이터는 'SQLitedb'에 로컬로 저장합니다. 누군가가 db에서 CRUD 작업을 수행한다면 모든 장치에서 업데이트해야합니다.

여기 Person 클래스 클래스입니다.

심지어 나는 listview를 사용하여 db의 모든 레코드를 표시합니다.

public class Person { 
// Labels table name 
public static final String DATABASE_NAME = "PersonInfo.db"; 

// Labels Table Columns names 
public static final String KEY_ROWID = "_id"; 
public static final String KEY_ID = "id"; 
public static final String CONTACTS_TABLE_NAME = "Person"; 
public static final String CONTACTS_COLUMN_FNAME = "FNAME"; 
public static final String CONTACTS_COLUMN_MNAME = "MNAME"; 
public static final String CONTACTS_COLUMN_LNAME = "LNAME"; 
public static final String CONTACTS_COLUMN_ADDRESS = "ADDRESS"; 
public static final String CONTACTS_COLUMN_YADINO = "YADINO"; 
public static final String CONTACTS_COLUMN_MOBILENO = "MOBILENO"; 
public static final String CONTACTS_COLUMN_VOTINGID = "VOTINGID"; 

// property help us to keep data 
public int person_ID; 
public String name; 
public String email; 
public int age; 

public String fname; 
public String mname; 
public String lname; 
public String address; 
public String yadino; 
public String mobileno; 
public String votingid; 


public int getPerson_ID() { 
    return person_ID; 
} 

public void setPerson_ID(int person_ID) { 
    this.person_ID = person_ID; 
} 

public String getName() { 
    return name; 
} 

public void setName(String name) { 
    this.name = name; 
} 

public String getEmail() { 
    return email; 
} 

public void setEmail(String email) { 
    this.email = email; 
} 

public int getAge() { 
    return age; 
} 

public void setAge(int age) { 
    this.age = age; 
} 

public String getFname() { 
    return fname; 
} 

public void setFname(String fname) { 
    this.fname = fname; 
} 

public String getMname() { 
    return mname; 
} 

public void setMname(String mname) { 
    this.mname = mname; 
} 

public String getLname() { 
    return lname; 
} 

public void setLname(String lname) { 
    this.lname = lname; 
} 

public String getAddress() { 
    return address; 
} 

public void setAddress(String address) { 
    this.address = address; 
} 

public String getYadino() { 
    return yadino; 
} 

public void setYadino(String yadino) { 
    this.yadino = yadino; 
} 

public String getMobileno() { 
    return mobileno; 
} 

public void setMobileno(String mobileno) { 
    this.mobileno = mobileno; 
} 

public String getVotingid() { 
    return votingid; 
} 

public void setVotingid(String votingid) { 
    this.votingid = votingid; 
} 
} 

다음은 db에서 작업을 수행하는 클래스입니다.

public class StudentRepo { private DBHelper dbHelper;

public StudentRepo(Context context) { 
    dbHelper = new DBHelper(context); 
} 

public int insert(Person person) { 

    //Open connection to write data 
    SQLiteDatabase db = dbHelper.getWritableDatabase(); 
    ContentValues values = new ContentValues(); 
    values.put(Person.CONTACTS_COLUMN_FNAME, person.getFname()); 
    values.put(Person.CONTACTS_COLUMN_MNAME, person.getMname()); 
    values.put(Person.CONTACTS_COLUMN_LNAME, person.getLname()); 
    values.put(Person.CONTACTS_COLUMN_ADDRESS, person.getAddress()); 
    values.put(Person.CONTACTS_COLUMN_YADINO,person.getYadino()); 
    values.put(Person.CONTACTS_COLUMN_MOBILENO, person.getMobileno()); 
    values.put(Person.CONTACTS_COLUMN_VOTINGID,person.getVotingid()); 

    // Inserting Row 
    long student_Id = db.insert(Person.CONTACTS_TABLE_NAME, null, values); 

    db.close(); // Closing database connection 
    return (int) student_Id; 
} 
public Cursor getStudentList() { 
    //Open connection to read only 
    SQLiteDatabase db = dbHelper.getReadableDatabase(); 
    String selectQuery = "SELECT rowid as " + 
      Person.KEY_ROWID + "," + 
      Person.KEY_ID + "," + 
      Person.CONTACTS_COLUMN_FNAME + "," + 
      Person.CONTACTS_COLUMN_MNAME + "," + 
      Person.CONTACTS_COLUMN_LNAME + "," + 
      Person.CONTACTS_COLUMN_ADDRESS + "," + 
      Person.CONTACTS_COLUMN_YADINO + "," + 
      Person.CONTACTS_COLUMN_MOBILENO + "," + 
      Person.CONTACTS_COLUMN_VOTINGID + 
      " FROM " + Person.CONTACTS_TABLE_NAME; 


    Cursor cursor = db.rawQuery(selectQuery, null); 
    // looping through all rows and adding to list 

    if (cursor == null) { 
     return null; 
    } else if (!cursor.moveToFirst()) { 
     cursor.close(); 
     return null; 
    } 
    return cursor; 


} 


public Cursor getStudentListByKeyword(String search) { 
    //Open connection to read only 
    SQLiteDatabase db = dbHelper.getReadableDatabase(); 
    String selectQuery = "SELECT rowid as " + 
      Person.KEY_ROWID + "," + 
      Person.KEY_ID + "," + 
      Person.CONTACTS_COLUMN_FNAME + "," + 
      Person.CONTACTS_COLUMN_MNAME + "," + 
      Person.CONTACTS_COLUMN_LNAME + "," + 
      Person.CONTACTS_COLUMN_ADDRESS + "," + 
      Person.CONTACTS_COLUMN_YADINO + "," + 
      Person.CONTACTS_COLUMN_MOBILENO + "," + 
      Person.CONTACTS_COLUMN_VOTINGID + 
      " FROM " + Person.CONTACTS_TABLE_NAME + 
      " WHERE " + Person.CONTACTS_COLUMN_FNAME + " LIKE '%" +search + "%' " 
      ; 


    Cursor cursor = db.rawQuery(selectQuery, null); 
    // looping through all rows and adding to list 

    if (cursor == null) { 
     return null; 
    } else if (!cursor.moveToFirst()) { 
     cursor.close(); 
     return null; 
    } 
    return cursor; 


} 

public Person getStudentById(int Id){ 

    SQLiteDatabase db = dbHelper.getReadableDatabase(); 
    String selectQuery = "SELECT " + 
      Person.KEY_ID + "," + 
      Person.CONTACTS_COLUMN_FNAME + "," + 
      Person.CONTACTS_COLUMN_MNAME + "," + 
      Person.CONTACTS_COLUMN_LNAME + "," + 
      Person.CONTACTS_COLUMN_ADDRESS + "," + 
      Person.CONTACTS_COLUMN_YADINO + "," + 
      Person.CONTACTS_COLUMN_MOBILENO + "," + 
      Person.CONTACTS_COLUMN_VOTINGID + 
      " FROM " + Person.CONTACTS_TABLE_NAME 
      + " WHERE " + 
      Person.KEY_ID + "=?";// It's a good practice to use parameter ?, instead of concatenate string 

    int iCount =0; 
    Person person = new Person(); 

    Cursor cursor = db.rawQuery(selectQuery, new String[] { String.valueOf(Id) }); 

    if (cursor.moveToFirst()) { 
     do { 
      person.person_ID =cursor.getInt(cursor.getColumnIndex(Person.KEY_ID)); 
      person.setFname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_FNAME))); 
      person.setMname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_MNAME))); 
      person.setLname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_LNAME))); 
      person.setAddress(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_ADDRESS))); 
      person.setYadino(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_YADINO))); 
      person.setMobileno(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_MOBILENO))); 
      person.setVotingid(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_VOTINGID))); 

     } while (cursor.moveToNext()); 
    } 

    cursor.close(); 
    db.close(); 
    return person; 
} 

public Person getStudentByName(String fname){ 
    // Log.d("SHAZ","ID OF STUDENT= "+String.valueOf(Id)); 
    SQLiteDatabase db = dbHelper.getReadableDatabase(); 
    String selectQuery = "SELECT " + 
      Person.KEY_ID + "," + 
      Person.CONTACTS_COLUMN_FNAME + "," + 
      Person.CONTACTS_COLUMN_MNAME + "," + 
      Person.CONTACTS_COLUMN_LNAME + "," + 
      Person.CONTACTS_COLUMN_ADDRESS + "," + 
      Person.CONTACTS_COLUMN_YADINO + "," + 
      Person.CONTACTS_COLUMN_MOBILENO + "," + 
      Person.CONTACTS_COLUMN_VOTINGID + 
      " FROM " + Person.CONTACTS_TABLE_NAME 
      + " WHERE " + 
      Person.CONTACTS_COLUMN_FNAME + "=?";// It's a good practice to use parameter ?, instead of concatenate string 

    int iCount =0; 
    Person person = new Person(); 

    Cursor cursor = db.rawQuery(selectQuery, new String[] { String.valueOf(Person.CONTACTS_COLUMN_FNAME) }); 

    if (cursor.moveToFirst()) { 
     do { 
      person.person_ID =cursor.getInt(cursor.getColumnIndex(Person.KEY_ID)); 
      person.setFname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_FNAME))); 
      person.setMname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_MNAME))); 
      person.setLname(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_LNAME))); 
      person.setAddress(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_ADDRESS))); 
      person.setYadino(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_YADINO))); 
      person.setMobileno(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_MOBILENO))); 
      person.setVotingid(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_VOTINGID))); 

     } while (cursor.moveToNext()); 
    } 

    cursor.close(); 
    db.close(); 
    return person; 
} 





} 

이리스트 뷰

public class CustomAdapter extends CursorAdapter { 
private LayoutInflater mInflater; 

public CustomAdapter(Context context, Cursor c, int flags) { 
    super(context, c, flags); 
    mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
} 


@Override 
public View newView(Context context, Cursor cursor, ViewGroup parent) { 
    View view = mInflater.inflate(R.layout.item, parent, false); 
    ViewHolder holder = new ViewHolder(); 
    holder.txtId = (TextView) view.findViewById(R.id.txtId); 
    holder.txtFname = (TextView) view.findViewById(R.id.txtdFname); 
    holder.txtMname = (TextView) view.findViewById(R.id.txtMname); 
    holder.txtLname = (TextView)view.findViewById(R.id.txtLname); 
    holder.txtVotingId = (TextView)view.findViewById(R.id.txtVotingId); 
    view.setTag(holder); 
    return view; 
} 

@Override 
public void bindView(View view, Context context, Cursor cursor) { 
    //If you want to have zebra lines color effect uncomment below code 
    /*if(cursor.getPosition()%2==1) { 
     view.setBackgroundResource(R.drawable.item_list_backgroundcolor); 
    } else { 
     view.setBackgroundResource(R.drawable.item_list_backgroundcolor2); 
    }*/ 

    ViewHolder holder = (ViewHolder) view.getTag(); 
    holder.txtId.setText(cursor.getString(cursor.getColumnIndex(Person.KEY_ID))); 
    holder.txtFname.setText(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_FNAME))); 
    holder.txtMname.setText(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_MNAME))); 
    holder.txtLname.setText(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_LNAME))); 
    holder.txtVotingId.setText(cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_VOTINGID))); 

} 

static class ViewHolder { 
    TextView txtId; 
    TextView txtFname; 
    TextView txtMname; 
    TextView txtLname; 
    TextView txtVotingId; 
} 
} 

에 대한 나의 CustomAdapter입니다 그리고 내가 중포 기지에서 사람 개체를 추가하는 경우이 내가 다시 검색 할 수 방법 다음 내 DBHelper 클래스

public class DBHelper extends SQLiteOpenHelper { 
//version number to upgrade database version 
//each time if you Add, Edit table, you need to change the 
//version number. 
private static final int DATABASE_VERSION = 1; 

// Database Name 
private static final String DATABASE_NAME = "Person.db"; 

public DBHelper(Context context) { 
    super(context, DATABASE_NAME, null, DATABASE_VERSION); 
} 

@Override 
public void onCreate(SQLiteDatabase db) { 
    //All necessary tables you like to create will create here 

    String CREATE_TABLE_STUDENT = "CREATE TABLE " + Person.CONTACTS_TABLE_NAME + "(" 
      + Person.KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT ," 
      + "FNAME" + " TEXT, " 
      + "MNAME" + " TEXT, " 
      + "LNAME" + " TEXT, " 
      + "ADDRESS" + " TEXT, " 
      + "YADINO" + " TEXT, " 
      + "MOBILENO" + " TEXT, " 
      + "VOTINGID" + " TEXT)"; 

    db.execSQL(CREATE_TABLE_STUDENT); 

} 

@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    // Drop older table if existed, all data will be gone!!! 
    db.execSQL("DROP TABLE IF EXISTS " + Person.CONTACTS_TABLE_NAME); 

    // Create tables again 
    onCreate(db); 

} 

} 

입니다 또는 db의 다른 장치에 로컬로 저장합니다.

이것은 내 수업입니다. 여기서 나는 db에 대한 모든 입력을 받고 있습니다.

public class AddPeopleActivity extends AppCompatActivity { 
Person per = null; 
StudentRepo student; 
EditText eFname,eMname,eLname,eAddress,eYadiNo,eMobileNo,eVoterNo; 
FancyButton btnAdd; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_add_people); 



    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 

    student = new StudentRepo(AddPeopleActivity.this); 



    final Person person = new Person(); 

    //init of EditText's 
    btnAdd = (FancyButton)findViewById(R.id.btnAddPeople); 
    eFname = (EditText)findViewById(R.id.eFname); 
    eMname = (EditText)findViewById(R.id.eMname); 
    eLname = (EditText)findViewById(R.id.eLname); 
    eAddress = (EditText)findViewById(R.id.eAddress); 
    eYadiNo = (EditText)findViewById(R.id.eYadiNo); 
    eMobileNo = (EditText)findViewById(R.id.eMobileNo); 
    eVoterNo = (EditText)findViewById(R.id.eVoterNo); 



    btnAdd.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Log.d("SHAZ","ADDPEOPLE ACTIVITY ONCLICK INVOKED"); 
      String efname = eFname.getText().toString(); 
      String emname = eMname.getText().toString(); 
      String elname = eLname.getText().toString(); 
      String eaddress = eAddress.getText().toString(); 
      String eyadi = eYadiNo.getText().toString(); 
      String emobileno = eMobileNo.getText().toString(); 
      String evoterno = eVoterNo.getText().toString(); 

      person.setFname(efname); 
      person.setMname(emname); 
      person.setLname(elname); 
      person.setAddress(eaddress); 
      person.setYadino(eyadi); 
      person.setMobileno(emobileno); 
      person.setVotingid(evoterno); 

      if(person!=null) { 

       student.insert(person); 
       Toast.makeText(AddPeopleActivity.this, "Person Added Successfully", Toast.LENGTH_SHORT).show(); 
       per = null; 
      } 

      myRef.addChildEventListener(new ChildEventListener() { 
       @Override 
       public void onChildAdded(DataSnapshot dataSnapshot, String s) { 
        for(DataSnapshot userSnap:dataSnapshot.getChildren()) 
        { 
         per = dataSnapshot.getValue(Person.class); 
         Cursor cursor = student.getStudentList(); 
         String cVoting = cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_VOTINGID)); 
         if(cVoting.equals(per.getVotingid())) 
         { 
          student.updateList(per); 
         }else{ 
          student.insert(per); 
         } 
        } 
       } 
     } 
    }); 

} 

이 내가 AddPeopleActivity

myRef.addChildEventListener(new ChildEventListener() { 
       @Override 
       public void onChildAdded(DataSnapshot dataSnapshot, String s) { 
        for(DataSnapshot userSnap:dataSnapshot.getChildren()) 
        { 
         per = dataSnapshot.getValue(Person.class); 
         Cursor cursor = student.getStudentList(); 
         String cVoting = cursor.getString(cursor.getColumnIndex(Person.CONTACTS_COLUMN_VOTINGID)); 
         if(cVoting.equals(per.getVotingid())) 
         { 
          student.updateList(per); 
         }else{ 
          student.insert(per); 
         } 
        } 
       } 

Answer 1

중포 기지에서 사용 아동의 이벤트 리스너에서 수행 한 방법이다. 이 리스너에는 추가, 변경, 이동, 삭제와 같은 많은 이벤트가 있으며 데이터베이스가 변경 될 때마다 실행됩니다. 이 방법으로 로컬 데이터베이스의 변경 사항을 모든 장치에 저장할 수 있습니다.

그냥 어린이의 말을 듣고 마법을 봅니다. https://firebase.google.com/docs/reference/admin/java/reference/com/google/firebase/database/ChildEventListener