I'm having some real problems passing a single string from my main activity to my db helper class. Here is my main activity method which I am returning a string 'answerSetId':
public String showNextRandomQuestion3() {
SQLDatabaseHelper db = new SQLDatabaseHelper(this);
//get the data from the database
List<List<String>> listList = db.getAllAnswersByQuestion1();
//Get the question/text/answer Strings
List<String> questionStrings = listList.get(0); //question Strings
List<String> answerSetIds = listList.get(4);
//Generate random index
Random r = new Random();
int rand = Math.abs((r.nextInt() % questionStrings.size()));
//get answer description for randomly selected question
String questionString = questionStrings.get(rand);
String answerSetId = answerSetIds.get(rand);
questionView.setText(questionString);
return answerSetId;
}
I specifically want to use this 'answerSetId' in one method in my db helper class (as part of a query). Here is my current code - but it is capturing an empty string '[]':
public List<List<String>> getAnswers(String answerSetId) {
List<String> array1 = new ArrayList<String>();
List<String> array2 = new ArrayList<String>();
System.out.println(answerSetId);
SQLiteDatabase db = this.getReadableDatabase();
String[] columns = new String[]{TDESCR, ADESCR};
String selection = ASID+"=?";
String[] selectionArgs = new String[]{String.valueOf(answerSetId)};
Cursor c = db.query(TABLE_ANSWERS, columns, selection, selectionArgs, null, null, null);
if (c.moveToFirst()) {
do {
String textdescr = c.getString(c.getColumnIndex(TDESCR));
String answersdescr = c.getString(c.getColumnIndex(ADESCR));
array1.add(textdescr);
array2.add(answersdescr);
} while (c.moveToNext());
}
List< List<String> > listArray2 = new ArrayList< List<String> >();
listArray2.add(array1);
listArray2.add(array2);
return listArray2;
}
You can see that I want to use this method to retrun some more array data based on the query using the 'answerSetId' string - you'll also see where I have added a system print out which gives the empty value '[]'. But am only bothered about actually capturing the 'answerSetId' value from my main activity at this point.
How best to achieve this?
the arrays of data I will then pass onto my 'showNextAnswer()' method:
public String showNextAnswers() {
SQLDatabaseHelper db = new SQLDatabaseHelper(this);
//get the data from the database
List<List<String>> listList = db.getAnswers(answerSetId);
//Get the question/text/answer Strings
List<String> textDescrs = listList.get(0); //question Strings
// List<String> answerDescrs = listList.get(1); //text strings
// System.out.println(answerSetId);
answerView3.setText(textDescrs.toString());
String textDescriptions = textDescrs.toString();
// String regex = "\\[|\\]";
// textDescriptions = textDescriptions.replaceAll(regex, "");
//Separate out the question/answer of text description associated with the randomly selected question
StringTokenizer textDescr = new StringTokenizer(textDescriptions, ",");
String first = textDescr.nextToken();
// String second = textDescr.nextToken();
// String third = textDescr.nextToken();
// String fourth = textDescr.nextToken();
subQuestionView1.setText(first);
// subQuestionView2.setText(second);
// subQuestionView3.setText(third);
// answerView3.setText(fourth);
// System.out.println(textDescr);
return null;
}
FYI - I call 'showNextRandomQuestion3()' from an onClick method when user clicks to go to a next question - a new random question and the related answers to that new question will appear each click:
NextQuestionButton.setOnClickListener(new OnClickListener(){;
#Override
public void onClick(View v) {
showNextRandomQuestion3();
showNextAnswers();
countQuestions();
}});
It looks like the solution is very simple. You just capture the return value of showNextRandomQuestion3(), since it returns answerSetId.
You will need to add a String parameter to the showNextAnswers() method to take the String that was returned from showNextRandomQuestion3().
So in your click event, you would do this:
NextQuestionButton.setOnClickListener(new OnClickListener(){;
#Override
public void onClick(View v) {
String answerSetId = showNextRandomQuestion3(); //get return value
showNextAnswers(answerSetId); //give the ID here
countQuestions();
}});
Then, just add the parameter to showNextAnswers(), and you're done!
public String showNextAnswers(String answerSetId) {
SQLDatabaseHelper db = new SQLDatabaseHelper(this);
//get the data from the database
List<List<String>> listList = db.getAnswers(answerSetId); //This will work now!
//.................
Related
i have data in sqlit database so i use it to store categoreis and items
and i get it in arraylist like this:
public ArrayList showDataItems(String id_cate){
ArrayList<Items> arrayListItems = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cr = db.rawQuery("select * from items where id_cate = "+id_cate,null);
cr.moveToFirst();
while (cr.isAfterLast() == false){
String item_id = cr.getString(0);
String ItemName = cr.getString(1);
String Item_quantity = cr.getString(2);
String icon = cr.getString(3);
int isDone = Integer.parseInt(cr.getString(5));
arrayListItems.add(new Items(item_id,ItemName,Item_quantity,R.drawable.shopicon,icon,isDone));
cr.moveToNext();
}
return arrayListItems;
}
so i need to get this data and convert it to string and share it to other application like whatsapp in custom format for example :
1- first one *
2- second one *
3-....
so i use this code for send data
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_TEXT,"hello world");
intent.setType("text/plain");
startActivity(Intent.createChooser(intent,"send items i need all
data here"));
so we can use string builder or some thing to get data in one string
please help me!
As you said, there is a StringBuilder class who can help formatting strings.
Here are the java docs
From StringBuilder, see the append(..) method. For your example:
int size = list.size();
for(int i = 0; i< size-1;i++){
stringBuilder.append(i+1).append("- ").append(list.get(i)).append('\n');
}
stringBuilder.append(size).append("- ").append(list.get(size-1));
The last call to append is different from the firstone by not appending the end line
My question is when i store the data into array from sqlite database, how can i get it from specific position let say, my database contain "food, drinks,snack" how can i get the string "snack" from array.
String CatNameQuery = "SELECT * FROM Category";
db = new DBController(MainActivity.this);
SQLiteDatabase db3 = db.getReadableDatabase();
final Cursor cursor2 = db3.rawQuery(CatNameQuery, null);
{
List<String> array = new ArrayList<String>();
while(cursor2.moveToNext()){
String uname = cursor2.getString(cursor2.getColumnIndex("CategoryName"));
array.add(uname);
}
You need to iterate through the list in order to find the item you are looking for.
For example:
for (String s : array) {
if (s.equals("snack")) {
System.out.println("Found snack");
}
}
You can also use the contains method to check if the list contains "snack."
if (array.contains("snack")) {
System.out.println("Found snack");
}
Resource: ArrayList
Use the WHERE clause within your SELECT query. For example:
"SELECT * FROM Category WHERE CategoryName='snacks'"
This will fill your array with only items under the category 'snacks'.
List<String> array = new ArrayList<String>();
array.add("food");
array.add("drinks");
array.add("snack");
String result="";
if (array.contains("snack")) // avoid null pointer exception
{
int index =array.indexOf("snack") //find the index of arraylist
result=array.get(index);
}
You can find it by looping the array
List<String> arrobj= new ArrayList<String>();
arrobj.add("food");
arrobj.add("drinks");
arrobj.add("snack");
for (String value : arrobj) {
if (value.equals("snack")) {
System.out.println("Here is the snack");
}
}
if (array.size() > 0) {
int index = 0;
if (array.contains("Snacks")) {
index = array.indexOf("Snacks");
System.out.println(array.get(index));
}
}
I have created a table below that has name of the places as its entryPoint in the first column. I want to keep a textfield so that one can search for the place he wants to view in the table.
How can i do this? For eg: if i type "a" in text field, all the places starting from "a" only are shown in the table.
json value for table
connectionRequest = new ConnectionRequest() {
#Override
protected void readResponse(InputStream input) throws IOException {
JSONParser p = new JSONParser();
results = p.parse(new InputStreamReader(input));
responseInout = (Vector) results.get("inout");
for (int i = 0; i < responseInout.size(); i++) {
Hashtable hash = (Hashtable) responseInout.get(i);
String entryPoint = (String) hash.get("entry_point");
String passengerIn = (String) hash.get("passenger_in");
String passengerOut = (String) hash.get("passenger_out");
String vehicleIn = (String) hash.get("vehicle_in");
String vehicleOut = (String) hash.get("vehicle_out");
dataInOut[i][0] = entryPoint;
dataInOut[i][1] = passengerIn;
dataInOut[i][2] = passengerOut;
dataInOut[i][3] = vehicleIn;
dataInOut[i][4] = vehicleOut;
}
}
connectionRequest.setPost(false);
connectionRequest.setUrl("http://capitaleyedevelopment.com/~admin/traffic/api/reports/getReports/2015-12-30");
connectionRequest.setDuplicateSupported(true);
NetworkManager.getInstance().addToQueueAndWait(connectionRequest);
//table
Table table = new MyTable(new DefaultTableModel(columnNamesInOut, dataInOut));
//what to do here in textField
TextField tf = new TextField();
tf.addDataChangeListener(new DataChangedListener() {
#Override
public void dataChanged(int type, int index) {
String searchPlace = tf.getText();
}
});
You can have two types of "search":
Data narrowing - this will hide the rows where the text doesn't show.
Highlight - this will highlight the cells where the data appears
If you choose the data narrowing route just create a new model without the rows that don't contain the data you want and invoke: table.setModel(searchModel); this will leave only the search results.
If you want the highlighting mode In the search field just call table.setModel(table.getModel()); this will force the table to rebuild.
Then override in the table:
protected Component createCell(Object value, int row, int column, boolean editable) {
Component c = super.createCell(value, row, column, editable);
if(isSearchedValue(value)) {
c.setUIID("SearchResult");
}
return c;
}
Then style SearchResult to be the highlight color you want and all is well...
I have managed to obtain the data from the SQLite database and plot the actual values for the cube line chart view. Since the values should be plotted against the date which is also stored in the database in the format (dd-mm-yyyy) and is expected to be plotted on the x, I have difficulties how to actually realize that. Current parts of my code like this:
hapinessdb.class (SQLite database and the code to search for the date entries)
/**
* Return the date as a string and place it to ArrayList
* of strings.
* #return
*/
public ArrayList<String> getDataForDate() {
ArrayList<String> dateValues = new ArrayList<String>();
String[] columns = new String[]{KEY_ROWID, KEY_DATE, KEY_TIME,KEY_HAPPY,
KEY_NORMAL, KEY_SAD };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null,
null, null, null, null); //Read the data from columns with cursor
String result = "";
int iDate= c.getColumnIndex(KEY_DATE);
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
result = c.getString(iDate);
dateValues.add(result);
}
return dateValues;
}
chart.class (method to obtain the ArrayList of date strings from happinessDb.class)
ArrayList<String> dateList = new ArrayList<String>();
private void dateDataFromDb() {
happinessDb dateInfo = new happinessDb(this);
try {
dateInfo.open();
} catch (SQLException e) {
e.printStackTrace();
}
ArrayList<String> data = dateInfo.getDataForDate();
dateInfo.close();
dateList = data; // Adds the dates to the String arrayList
My question is aimed towards, how to break the ArrayList of Strings and use them as part of the X-Axis series together with the bellow addHappyData method which plots the Integer values from ArralyList of Integers.
private void addHappyData() {
Integer x = 0;
for (Integer happy : happyList) {
mCurrentSeries.add(x += 20, happy);
}
}
Thank you for your time,review, possible review and answer on this post,
brg
Animus
I'm trying to retrieve a column (a database column where names are saved) and puting them to a listview. I have a class called Data with "getters" and "setters".
The following code is placed in a DBHandler class which extends SQLiteOpenHelper. This code is called from the MainActivity.java where the listview is meant to be updated with an onClickButton event.
public String[] getNames (int a, int b) {
String[] names = new String[] {};
String selectQuery = "SELECT * FROM " + TABLE_NAME
+ " WHERE " + KEY_ONE + " = ? AND " + KEY_TWO + " = ?";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, new String[]{String.valueOf(a), String.valueOf(b)});
if (cursor.moveToFirst()) {
int i = 0;
do {
Data myData = new Data();
names [i] = cursor.getString(1); //Names in cursor
++i;
} while (cursor.moveToNext());
}
return names;
}
In the MainActivity.java I call the following code before updating and notifying the update of the listview adapter:
values = db.getNames (1, 1);
I don't know why but this isn't working, it throws many errors with String lengths and crashes the app when I click the button that is suposed to enter the onClickButton.
Thanks
Follow the laalto answer and at last convert your ArrayList to Array like below:
String[] arrRecords = names.toArray(new String[names.size()]);
String[] names = new String[] {};
...
names [i] = cursor.getString(1); //Names in cursor
You're assigning to an empty array which causes ArrayIndexOutOfBoundsException.
Consider using a list such as ArrayList where you can append your values, e.g.
List<String> names = new ArrayList<String>();
...
names.add(cursor.getString(1));
If you really need to return a String[], you can convert the list with toArray():
String[] arr = new String[names.size()];
names.toArray(arr);
return arr;
Also, when posting questions that involve exceptions, always include the exception stacktrace from logcat in the question itself.
Why use like this
String[] names = new String[] {}; //no size
names [i] = cursor.getString(1); //it can work?
Use ArrayList<String>
List<String> names = new ArrayList<String>(); //declare
names.add(<column-val>); //add column value to list