Android工作室中的SQL Lite不会插入属性

时间：2016-12-22 23:54:33

标签： android sql database nullpointerexception android-sqlite

我已经有这个问题了一段时间了。由于某种原因，它将它添加到数据库，但它会出现此错误并导致程序崩溃。

java.lang.NullPointerException：尝试调用虚拟方法'long com.example.munaj.feedmeg.DataBaseHelper.insertRow（java.lang.String，java.lang.String，java.lang.String，java.lang。对象引用上的String，java.lang.String，java.lang.String，java.lang.String）'

有很多随机填充，但我找到了我的错误。

enter image description here

这是我的数据库文件

public class DataBaseHelper extends SQLiteOpenHelper{

private static final String TAG = "DBAdapter"; // used for logging database version

//Field Names:
public static final String KEY_ROWID = "_id";
public static final String KEY_TASK = "task";
public static final String KEY_DATE = "date";
public static final String KEY_START_TIME = "sTime";
public static final String KEY_FINISH_TIME = "fTime";
public static final String KEY_LOC = "loc";
public static final String KEY_ROOM = "room";
public static final String KEY_DES = "des";


public static final String[] ALL_KEYS = new String[] {KEY_ROWID, KEY_TASK, KEY_DATE,KEY_START_TIME, KEY_FINISH_TIME, KEY_LOC, KEY_ROOM, KEY_DES};

public static final int COL_ROWID = 0;
public static final int COL_TASK = 1;
public static final int COL_DATE = 2;
public static final int COL_FTIME = 3;

//Column Numbers for each Field Name:
public static final String DATABASE_NAME = "dbToDo";
public static final String DATABASE_TABLE = "mainToDo";
public static final int DATABASE_VERSION = 5;

//SQL statement to create database
private static final String DATABASE_CREATE_SQL =
        "CREATE TABLE " + DATABASE_TABLE
        + " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
        + KEY_TASK + " TEXT NOT NULL, "
        + KEY_DATE + " TEXT, "
        + KEY_START_TIME + " TEXT NOT NULL,"
        + KEY_FINISH_TIME + " TEXT NOT NULL,"
        + KEY_LOC + " TEXT NOT NULL,"
        + KEY_ROOM + " TEXT NOT NULL,"
        + KEY_DES + " TEXT NOT NULL"
        + ");";

private final Context context;
private DatabaseHelper myDBHelper;
private SQLiteDatabase db;

public DataBaseHelper(Context ctx) {
    super(ctx, DATABASE_NAME, null, DATABASE_VERSION);
    this.context = ctx;
    myDBHelper = new DatabaseHelper(context);
}
//Open the database connection
public DataBaseHelper open(){
    db = myDBHelper.getWritableDatabase();
    return this;
}
//Close the database connection
public void close(){
    myDBHelper.close();
}

@Override
public void onCreate(SQLiteDatabase db) {

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

//Add a new set of values to be inserted into the database.
public long insertRow(String task, String date,String startTime, String finishTime, String loc, String room, String des){
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_TASK, task);
    initialValues.put(KEY_DATE,date);
    initialValues.put(KEY_START_TIME,startTime);
    initialValues.put(KEY_FINISH_TIME,finishTime);
    initialValues.put(KEY_LOC,loc);
    initialValues.put(KEY_ROOM,room);
    initialValues.put(KEY_DES,des);


    //Insert the data into the database
    return db.insert(DATABASE_TABLE, null, initialValues);
}
//Delete a row from the database, by rowId(primary key)
public boolean deleteRow(long rowId){
    String where = KEY_ROWID + "=" + rowId;
    return db.delete(DATABASE_TABLE, where, null) != 0;
}

public void deleteAll(){
    Cursor c = getAllRows();
    long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
    if(c.moveToFirst()){
        do{
            deleteRow(c.getLong((int)rowId));
        }while (c.moveToNext());
    }
    c.close();
}
//Return all data in the database.
public Cursor getAllRows(){
    Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS, null, null, null, null, null, null);
    if(c != null){
        c.moveToFirst();
    }
    return c;
}
//Return all data in the database.
public Cursor getRow(long rowId){
    String where = KEY_ROWID + "=" + rowId;
    Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS,where,null,null,null,null,null);
    if(c != null){
        c.moveToFirst();
    }
    return c;
}
//Change an existing row to be equal to new data.
public boolean updateRow(long rowId, String task, String date,String startTime, String finishTime, String loc, String room, String des){
    String where = KEY_ROWID + "=" + rowId;
    ContentValues newValues = new ContentValues();
    newValues.put(KEY_TASK,task);
    newValues.put(KEY_DATE, date);
    newValues.put(KEY_START_TIME,startTime);
    newValues.put(KEY_FINISH_TIME,finishTime);
    newValues.put(KEY_LOC, loc);
    newValues.put(KEY_ROOM, room);
    newValues.put(KEY_DES, des);

    //Insert it into the database.
    return db.update(DATABASE_TABLE,newValues,where,null) != 0;
}

private static class DatabaseHelper extends SQLiteOpenHelper {
    DatabaseHelper(Context context){
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase _db){
        _db.execSQL(DATABASE_CREATE_SQL);
    }

    @Override
    public void onUpgrade(SQLiteDatabase _db, int oldVersion, int newVersion){
        Log.w(TAG, "Upgrading Application's database from version " + oldVersion
                + " to " + newVersion + ", which will destroy all old data!");
        //Destroy old database;
        _db.execSQL("DROP TABLE IF EXISTS " +  DATABASE_TABLE);
        //Recreates new database:
        onCreate(_db);

    }
}
}

主程序

public class MainActivity extends AppCompatActivity {
DataBaseHelper myDb;
//Time zone
Time today = new Time(Time.getCurrentTimezone());
String etTasks;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    etTasks = "KKKK";
    openDB();
    populateListView();
    //listViewItemClick();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}
//Opening the database
public void openDB(){
    myDb = new DataBaseHelper(this);
    myDb.open();
}
public void insertMe(String a, String s, String d, String f, String g, String h, String j){
(****ERROR HERE****)myDb.insertRow(a,s,d,f,g,h,j);
    populateListView();
}
public void populateListView(){
    //Cursor went into data base and got all the rows
    Cursor cursor = myDb.getAllRows();
    if(cursor.getCount() == 0){
        Toast.makeText(this, "PARTYYY", Toast.LENGTH_LONG).show();

        return;
    }
    //then places them into these arrays
    String[] fromFieldNames = new String[]{
            DataBaseHelper.KEY_START_TIME,DataBaseHelper.KEY_TASK,DataBaseHelper.KEY_LOC, DataBaseHelper.KEY_FINISH_TIME, DataBaseHelper.KEY_DATE, DataBaseHelper.KEY_ROOM, DataBaseHelper.KEY_DES};
    int[] toViewIDs = new int[] {
            R.id.sTime, R.id.food,R.id.loc, R.id.fTime, R.id.date, R.id.room, R.id.des};
    SimpleCursorAdapter myCursorAdapter;
    myCursorAdapter = new SimpleCursorAdapter(getBaseContext(),R.layout.item_layout, cursor,fromFieldNames,toViewIDs,0);
    ListView myList = (ListView) findViewById(R.id.listView);
    myList.setAdapter(myCursorAdapter);
}

private void updateTask(long id){
    Cursor cursor = myDb.getRow(id);
    if(cursor.moveToFirst()){
        String task = etTasks;
        String fTime = "2pm";
        String sTime = "12pm";
        String loc = "UC";
        String room = "103";
        String des = "Fun Event Great Time";
        today.setToNow();
        String date = today.format("%Y-%m-%d %H:%M:%S");
        myDb.updateRow(id,task,date,sTime,fTime,loc,room,des);
    }
    cursor.close();
}

private void listViewItemClick(){
    ListView myList = (ListView)findViewById(R.id.listView);
    myList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long id) {
            updateTask(id);
            populateListView();
        }
    });
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        //getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#F44336")));
        return true;
    }

    else if (id == R.id.action_login)
    {
        Intent intent = new Intent(MainActivity.this, Clubs.class);
        startActivity(intent);
    }

    return super.onOptionsItemSelected(item);
}
}

俱乐部计划

public class Clubs extends AppCompatActivity implements AdapterView.OnItemSelectedListener{
EditText clubName;
TextView nameError;
TextView dateError;
TextView locError;
TextView startError;
TextView endError;
TextView foodError;
TextView desError;

ImageButton add;
ImageButton date;
ImageButton loc;
ImageButton sTime;
ImageButton eTime;
ImageButton foodType;

Button des;

int year, month, day;
int hour, minute, eHour, eMinute;
String name, description = "", location = "---", food = "---";
ArrayList<Library> library = new ArrayList<>();

Library lib = new Library();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_clubs);
    des = (Button) findViewById(R.id.btnDes);
    clubName = (EditText) findViewById(R.id.txtName);
    nameError = (TextView) findViewById(R.id.lblNameError);
    dateError = (TextView) findViewById(R.id.lblDError);
    locError = (TextView) findViewById(R.id.lblLError);
    startError = (TextView) findViewById(R.id.lblSError);
    endError = (TextView) findViewById(R.id.lblFinError);
    foodError = (TextView) findViewById(R.id.lblFoError);
    desError = (TextView) findViewById(R.id.lblDesError);

    add = (ImageButton) findViewById(R.id.btnAdd);

    date = (ImageButton) findViewById(R.id.btnDate);
    loc = (ImageButton) findViewById(R.id.btnLoc);
    sTime = (ImageButton) findViewById(R.id.btnSTime);
    eTime = (ImageButton) findViewById(R.id.btnETime);
    foodType = (ImageButton) findViewById(R.id.btnFood);

    date.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            final Calendar cal = Calendar.getInstance();
            year = cal.get(Calendar.YEAR);
            month = cal.get(Calendar.MONTH);
            day = cal.get(Calendar.DAY_OF_MONTH);

            DatePickerDialog dDate =  new DatePickerDialog(Clubs.this, dpickerListner, year, month, day);
            dDate.show();
            DatePickerDialog.OnDateSetListener dpickerListner
                    = new DatePickerDialog.OnDateSetListener(){
                @Override
                public void onDateSet(DatePicker view, int year_x, int month_x, int day_x){
                    year = year_x;
                    month = month_x + 1;
                    day = day_x;

                    Toast.makeText(Clubs.this, year + "/" + month + "/" + day, Toast.LENGTH_LONG).show();
                }
            };
        }
    });

    loc.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            final Dialog dialog = new Dialog(Clubs.this);
            dialog.setTitle("Building");
            dialog.setContentView(R.layout.description_dialog);
            dialog.show();

            Button done = (Button) dialog.findViewById(R.id.btnDone);
            final EditText dDialog = (EditText) dialog.findViewById(R.id.txtDes);
            done.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    location = dDialog.getText().toString();
                    Toast.makeText(Clubs.this, "Saved " + location, Toast.LENGTH_LONG).show();
                    dialog.cancel();
                }
            });
        }
    });

    sTime.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            TimePickerDialog tTime = new TimePickerDialog(Clubs.this, sTimePickerListner, hour, minute,false);
            tTime.show();
        }
    });

    eTime.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            TimePickerDialog tTime = new TimePickerDialog(Clubs.this, eTimePickerListner, eHour, eMinute,false);
            tTime.show();
        }
    });

    foodType.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final Dialog dialog = new Dialog(Clubs.this);
            dialog.setTitle("Food");
            dialog.setContentView(R.layout.food_spinner_dialog);
            dialog.show();

            final Spinner spinner = (Spinner) dialog.findViewById(R.id.spinner_food);
            final ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(Clubs.this, R.array.Food, android.R.layout.simple_spinner_item);
            adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);
            spinner.setAdapter(adapter);
            spinner.setOnItemSelectedListener(Clubs.this);

            Button done = (Button) dialog.findViewById(R.id.btnSpDoneFood);
            done.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    food = spinner.getSelectedItem().toString();
                    if (food.equals("---")) {
                        Toast.makeText(Clubs.this, "Pick a Food item!, " + food, Toast.LENGTH_LONG).show();
                    } else {
                        Toast.makeText(Clubs.this, "Saved, " + food, Toast.LENGTH_LONG).show();
                        dialog.cancel();
                    }
                }
            });
        }
    });

    des.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final Dialog dialog = new Dialog(Clubs.this);
            dialog.setTitle("Description of Event");
            dialog.setContentView(R.layout.description_dialog);
            dialog.show();

            Button done = (Button) dialog.findViewById(R.id.btnDone);
            final EditText dDialog = (EditText) dialog.findViewById(R.id.txtDes);
            done.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    description = dDialog.getText().toString();
                    Toast.makeText(Clubs.this, "Saved", Toast.LENGTH_LONG).show();
                    dialog.cancel();
                }
            });
        }
    });

    add.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //Food product = new Food(clubName.getText().toString());

            if (clubName.getText().toString().equals("") || year == 0 || month == 0 || day == 0 || hour == 0 || eHour == 0 || location.equals("---") || description.equals("")) {
             Toast.makeText(Clubs.this, "Input Error, check all fields", Toast.LENGTH_LONG).show();
            }

            else{
            lib.addItem(year, month, day, location, hour, minute, eHour, eMinute, food, description);
            Toast.makeText(Clubs.this, "Added Successfully", Toast.LENGTH_LONG).show();

                Toast.makeText(Clubs.this, "PARTYYY", Toast.LENGTH_LONG).show();

                String dateBooked = (month + " " + day + ", " + year);
                String startTime = (hour + ":" + minute);
                String finishTime = (eHour + ":" + eMinute);
                int room = 222;
                String locc = "UC";
                String dess = "LOOL";
                String x = clubName.getText().toString();
                Toast.makeText(Clubs.this,clubName.getText().toString()  + "... " + startTime + " .." + finishTime + ".. loc: " + location + "..food: " +food + description, Toast.LENGTH_LONG).show();

(****ERROR HERE****)new MainActivity().insertMe("dude","a","a","a","a","a","a");**



                Intent intent = new Intent(Clubs.this, MainActivity.class);
                startActivity(intent);

            }

            if (clubName.getText().toString().equals("")) {
                nameError.setVisibility(View.VISIBLE);
            } else {
                nameError.setVisibility(View.INVISIBLE);
            }

            if (year == 0 || month == 0 || day == 0) {
                dateError.setVisibility(View.VISIBLE);
            } else {
                dateError.setVisibility(View.INVISIBLE);
            }

            if (hour == 0) {
                startError.setVisibility(View.VISIBLE);
            } else {
                startError.setVisibility(View.INVISIBLE);
            }

            if (eHour == 0) {
                endError.setVisibility(View.VISIBLE);
            } else {
                endError.setVisibility(View.INVISIBLE);
            }

            if (location.equals("---")) {
                locError.setVisibility(View.VISIBLE);
            } else {
                locError.setVisibility(View.INVISIBLE);
            }

            if (description.equals("")) {
                desError.setVisibility(View.VISIBLE);
            } else {
                desError.setVisibility(View.INVISIBLE);
            }
        }
    });

}
//*****************************************************DATE PICKER***************************************************************
private DatePickerDialog.OnDateSetListener dpickerListner
        = new DatePickerDialog.OnDateSetListener(){
    @Override
    public void onDateSet(DatePicker view, int year_x, int month_x, int day_x){
        year = year_x;
        month = month_x + 1;
        day = day_x;

        Toast.makeText(Clubs.this, "Saved!", Toast.LENGTH_LONG).show();
    }
};
//*****************************************************TIME PICKER***************************************************************

protected TimePickerDialog.OnTimeSetListener sTimePickerListner =
        new TimePickerDialog.OnTimeSetListener() {
            @Override
            public void onTimeSet (TimePicker view, int hour_x, int minute_x){
                hour = hour_x;
                minute = minute_x;
                Toast.makeText(Clubs.this, "Saved!", Toast.LENGTH_LONG).show();
            }
        };
protected TimePickerDialog.OnTimeSetListener eTimePickerListner =
        new TimePickerDialog.OnTimeSetListener() {
            @Override
            public void onTimeSet (TimePicker view, int hour_x, int minute_x){
                eHour = hour_x;
                eMinute = minute_x;
                Toast.makeText(Clubs.this,"Saved!", Toast.LENGTH_LONG).show();
            }
        };

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_clubs, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    else if (id == R.id.action_sign_out)
    {
        Intent intent = new Intent(Clubs.this, MainActivity.class);
        startActivity(intent);
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    TextView myText = (TextView) view;
    food = (String) myText.getText();
    if (!food.equals("---")) {
        Toast.makeText(this, "Food:  " + food, Toast.LENGTH_LONG).show();
    }
}

@Override
public void onNothingSelected(AdapterView<?> parent) {

}
}

1 个答案:

答案 0 :(得分：1)

从未运行的Activity调用NullPointerException方法导致DataBaseHelper。

要使其工作，请在Clubs活动中创建insertRow类对象，然后调用DataBaseHelper myDb = new DataBaseHelper(this); myDb.insertRow(); 方法。 

set(handles.text1,'String',sprintf('%-s\n%-s',a,Fs))
相关问题
最新问题