"Null" appended to database input values from a delimited string

Question

I wonder if someone could show me the error of my ways--I've been struggling with this issue for two days, and realize it must be a fundamental error of initializing variables, but...that reflects the level of my java knowledge.

I'm getting a database result on a delimited string wherein each of the segments has "null" appended to it. It seems that no matter how I change the initialization...well, two days!

I'm declaring the following in the class heading area:

private String strListContent;
private SQLiteDatabase database;
private DatabaseHelper helper2 = new DatabaseHelper(this);
private static final String fields[] = { "_id", "listTitle", "listType",
        "listContent", "dateCreated", "dateModified" };
private ArrayList<String> textArray = new ArrayList<String>();
private ArrayList<Integer> imageArray = new ArrayList<Integer>();

Then concatenating my items in

final ImageButton addItem = (ImageButton) findViewById(R.id.btnToAddItem);
addItem.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
    itemEdit = (EditText) findViewById(R.id.editTextItem);

    if (itemEdit.getText().toString().equals("")) {
        showToastMessage("Please enter an item to add...");

    } else {

        String newListItem = itemEdit.getText().toString();
        strListContent += newListItem + "|~|";

...
}}}

I'm using the following bare-bones SQLiteOpenHelper:

public class DatabaseHelper extends SQLiteOpenHelper {

public static final String KEY_ID = "_id";

public DatabaseHelper(Context context) {
    super(context, "Cursor", null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE IF NOT EXISTS list_data ("
            + KEY_ID
            + " INTEGER PRIMARY KEY AUTOINCREMENT, listTitle TEXT, listType TEXT,    listContent TEXT, dateCreated TEXT, dateModified TEXT)");

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // Steps to upgrade the database for the new version ...
}
}

To insert the values as so:

ImageButton saveAndBack = (ImageButton) findViewById(R.id.btnSaveBack);
saveAndBack.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {

        String title = null;
        String listContent = null;
        Calendar javaCalendar = null;

        title = titleEdit.getText().toString();
        title = (title=="" || title==null)?"Untitled List":title;
        strListContent = (strListContent=="" || strListContent==null)?"No Items|~|":strListContent;
        listContent = strListContent;
        String type = "R"; //"Regular List"

        javaCalendar = Calendar.getInstance();
        String currentDate = javaCalendar.get(Calendar.MONTH) + "/" +   (javaCalendar.get(Calendar.DATE) + 1) + "/" + javaCalendar.get(Calendar.YEAR);

        database = helper2.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put("listTitle", title);
        values.put("listType", type);
        values.put("listContent", listContent);
        values.put("dateCreated", currentDate);
        values.put("dateModified", currentDate);

        database.insert("list_data", null, values);

        Intent i = new Intent(RegularList.this, ActivityMain.class);
        startActivity(i);

    }
});


}
//
//End of OnCreate(){}
//

Then, when I retrieve from another activity:

DatabaseHelper helper = new DatabaseHelper(this);
database = helper.getWritableDatabase();

    Cursor data = database.query("list_data", fields, null, null, null,
            null, null);
    Integer tindex = data.getColumnIndex("listTitle");
    Integer iindex = data.getColumnIndex("listType");
    Integer cindex = data.getColumnIndex("listContent");

    itemCount = 0;
    for (data.moveToFirst(); !data.isAfterLast(); data.moveToNext()) {
        showToastMessage(data.getString(cindex));
        titleArrayList.add(data.getString(tindex));

        if (data.getString(iindex) == "R") {
            imageArrayList.add(R.drawable.listview_regular);
        } else if (data.getString(iindex) == "L") {
            imageArrayList.add(R.drawable.listview_location);
        } else {
            imageArrayList.add(R.drawable.listview_regular);
        }

        itemCount++;

    }

    data.close();

...

I can see in the toast message that each item from the delimited string has "null" appended to the front of it...the other values are fine. I hope this hasn't been too verbose, but...any recommendations? Thanks!

martin clayton · Accepted Answer · 2013-03-27 00:16:29Z

2

To me it looks like you may have simply not initialised the String strListContent before you first append to it with:

strListContent += newListItem + "|~|";

When you do that, you'll get a "null" prefixed in front of the value you are trying to append, just as you observe.

Perhaps you can just initialise in the declaration:

private String strListContent = "";

edited Mar 27, 2013 at 0:16

answered Mar 26, 2013 at 23:54

martin clayton

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2 Comments

kwishnu Over a year ago

I realize it sounds ridiculous, but could you show me how and where I should do that? I've tried many ways and none seems to work...pretend I don't know anything about java, which isn't too far off base! Thanks

kwishnu Over a year ago

Omg...I could swear I had it that way at one point...what can I say? Thanks for the help, that was all it was! Where are the emoticons to show red cheeks?

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