Can anybody suggest what functionality to provide in a query utility class/classes? The idea is to provide a database utility package for android developers. I just wanna do it for android community and of course for my learning.:-)
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Sometimes I need to provide a Context object to call specific functions, such as
Intent intent = new Intent(context, MyClass.class);
in order to start a service
context.startService(intent);
Or, provide a Context object to do a query
Cursor cursor = context.managedQuery(uri, projection, null, null, null);
If this is done in a UI class which extends Activity, that's fine.
However, If I want to create my own utility class (a singleton) that doesn't extend anything and call these functions, I don't have necessary Context object. Now my workaround is to pass an activity reference while initializing the utility class and have that reference to call those functions. I'm wondering what's the correct way to do that. It should not be reasonable to have every class to extends Context so that it can call those functions.
I successfully created the Database and inserted a row however I cannot Query it for some reason. My Droid crashes everytime.
CODE:...........
I get this exception
No such column: value: , while compiling: SELECT DISTINCT value FROM mainTable
In android, How can I query the name of the MMS sender and text of the MMS from MMS database? For SMS, there are these 2 columns for that: Sms.PERSON_ID and Sms.Body. But what is the equivalent columns in MMS Table?
View 1 Replies View RelatedI wanted to remove duplicates from the database. In my db duplication can be defined by combination of multiple columns. For example :............
View 5 Replies View RelatedIn my android app i need to get 50,000 database entry(text) and compare them with a value when the activity started(in onCreate()).I am doing this with the simplest way : i get the whole table from db to a cursor.However this way is too laggy.Are there any other way to do it more effective?The app is "scrabble solver" that is why i am not using WHERE close in my query (Take the whole data annd compare it with combination of the input letters).At first i was using a big table which contains whole possible words.Now i am using 26 tables.This reduced the lag and i am making database call on a thread that solved a lot problems too.It is still little bit laggy but much better.
View 4 Replies View RelatedCan you please tell me how can I query all phone numbers of all Contacts in the Database? Where can I find some examples for that?
View 3 Replies View RelatedI'm trying to deploy an application with an existing SQLite database.I've been reading though the examples that are posted but they are always missing some part of the class. I feel like I'm trying to bake muffins but no one told me to use baking powder.Can someone post a full database helper class for depoying an SQLite database on Android? Edit : Delete old code because it doesn't work.
View 2 Replies View RelatedI'm populating a listview from a database query and I can't seem to figure out what is going wrong.
As you will see in the image, the query is returning some sort of id. I've done a ton of googling, but the problem is that I don't know what to search!
I'm writing an RSS reader for Android. I've faced a certain difficulty which the problem I can't resolve since databases aren't my expertise.. So i figured out maybe one of you could help me out! I currently have 3 tables (Categories, links and feeds). My goal is too link a feed to multiple categories. Therefor I'm using a Link table. My databases is an Android ContentProvider (sqlite) and looks like the following:
| Categories | | Links | | Feeds |
|------------| |---------| |-------|
| _ID | | Category| | _ID |
| Title | | Feed | | Title |
| URL |
I currently wrote the following code in my FeedListActivity to retrieve a list of links and their feeds.
CODE:.................
Now my question:
I was wondering how I could optimize this database layout, code or query so I would get my entries in a more efficient way. Because i believe this link table or the query to retrieve links isn't needed! Or am i doing this the correct way?
I am new to Android, and I haven't developed any app regarding databases on Android yet. So I have a few basic questions. I am after a good database class sample, that will let me to run the CRUD operations. I would like to use it as a static class
like: clsDB->Select("select * from clients");
or objClient->Delete(clientid);
I am wondering if someone, can share his database classes, if more people share the best. Also I have in mind to reuse this class in multiple ways, I will have services, activities etc...
Here is my code for my db class:
package one.two;
import java.util.List;
import android.app.ListActivity;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import java.util.ArrayList;
public class DBAdapter extends ListActivity
{public String status = "status";
public String id = "id";
public String arrival = "arrival";
public String destination = "destination";
public String ferry = "ferry";
private static String DB_PATH = "/data/data/one.two/databases/";
private static final String DATABASE_NAME = "ferry.db";
private static final String DATABASE_TABLE = "port";
public static Context context;
public Cursor c;
public static SQLiteDatabase DbLib;
//overloaded non-null constructor
public DBAdapter(Context context) {
DbLib = context.openOrCreateDatabase(DATABASE_NAME,
SQLiteDatabase.CREATE_IF_NECESSARY,null);
System.out.println("OpenOrCreateDB Done");
} public class DatabaseHelper extends SQLiteOpenHelper {
Context context;
DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}//end constructor DatabaseHelper
// ---closes the database---
public void close() {
DBHelper.close();
}//end close()
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion){
}//end onUpgrade()
@Override
public void onCreate(SQLiteDatabase db){
}//end onCreate()
}// end class DatabaseHelper
private static DatabaseHelper DBHelper;
private static final int DATABASE_VERSION = 1;
public static ArrayList<String> getAllTitles(){
ArrayList<String> port = new ArrayList<String>();
Cursor c=null;
c = DbLib.query("port"
new String[] { "status", "id", "arrival",
"destination", "ferry" }, null, null,
null, null, null);
try {
if (c!=null) { // start - when there is at least 1 record
System.out.println("Cursor is NOT NULL");
int i =0;
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())
{// Debug Stm
System.out.println("Record No. "+i);
System.out.println(c.getString(0));
System.out.println(c.getString(1));
System.out.println(c.getString(2));
System.out.println(c.getString(3));
System.out.println(c.getString(4));
// Assign database cursor.records to arraylist
port.add(i,c.getString(0));
port.add(i,c.getString(1));
port.add(i,c.getString(2));
port.add(i,c.getString(3));
port.add(i,c.getString(4));
i = i + 1;
} } // end - where there is at least 1 record
} finally {
if (c!=null) {
c.close();
} } return port;
}//end getAllTitles()
public void open() {
//Open the database
String myPath = DB_PATH + DATABASE_NAME;
DbLib = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
} }//end class DBAdapter
My Arrival class
package one.two;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class Arrival extends ListActivity
{ private ListView listView;
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState)
{ ArrayList<String> retList = new ArrayList<String>();
System.out.println("Start onCreate Function");
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
System.out.println("In onCreate Function");
System.out.println("In of GetData");
DBAdapter db = new DBAdapter(this);
System.out.println("DB Open");
db.open();
System.out.println("DB Opened");
retList = getData();
System.out.println("Out of GetData");
// force count no. of records in table
// dump to check index
int cnt = 2;
int i=0;
for (i = 0; i<cnt; i++)
System.out.println(retList.toString());
listView = (ListView) findViewById(android.R.id.list);
SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this, android.R.id.list, null, null, null);
this.setListAdapter(mAdapter);
// db.close();
} @SuppressWarnings("static-access")
public static ArrayList<String> getData()
{ ArrayList<String> items = DBAdapter.getAllTitles();
// titles ???? redundant
//ArrayList<String> titles = new ArrayList<String>(items);
System.out.println("Return a LIST titles");
return items;
} }
When I create a instance of the SQLiteOpenHelper, I always need a "Context" to be passed as its constructor's argument. To use this "Context", in my service layer class, I extends Activity class, though I do not display this activity on the screen because it is my service layer. I always get NullPointer exception when I open the SQLiteOpenHelper in my service layer class, Is it because my service layer class extends the Activity class but I did not show this activity on mobile screen? (That's there is no intent to my service layer class), if it is so, how to get rid of it if I wanna open a SQLiteOpenHelper in my service layer class which do not need to extends Activity, but need a Context object to pass to SQLiteOpenHelper?
View 2 Replies View RelatedI want to run this query in Android Application :
code:.......
My DB schema
code:..........
Here is the function -
code:...........
My app uses two databases (separate files). To handle these databases I have created two Helper classes which extend SQLiteOpenHelper, one for each database.
I am now going to add a third database and wonder whether I need to create yet another Helper class (and if I used a 4th and a 5th database would I need even more Helper classes), or can I use the same Helper class for multiple databases?
The problem that I see with trying to use just one Helper class is that I can't see how to pass the name of the individual database files to the Helper. At present the name of the database is hard-coded as a Static field of each of the Helper classes, but if I had only one Helper class I would need to be able to pass the different names in to the Constructor when creating the separate Helper objects; the problem is that the SQLiteOpenHelper Constructor seems to be called by Android with just one parameter: the Context.
I have developed an application and want to sign it. After signing the application when I try to Align the final package with zipalign. But there's no file called zipalign in tools directory. Can someone guide me regarding this?
Moreover, after signing the application when I try to install the application it gave me "com.satloc signatures do not match the previously installed version; ignoring!". To remove this error I tried -wipe_data. After doing this I again tried to load the application with adb install SatLoc.apk but it again gave me an error this time it
DDM dispatch reg wait timeout Can't dispatch DDM chunk 52454151: no handler defined Can't dispatch DDM chunk 48454c4f: no handler defined pkg: /data/local/tmp/SatLoc.apk Failure [-12]
What is this and how to remove this? I want to load the signed application in emulator. Is zipalign necessay for this purpose? If yes then from where can I get zipalign utility.
I have a little idea of the Utility Classes with a slight doubt on demand.
If I use a Utility class in my Application than to use that class in my main Activity do I have to create the object of that class or I can directly Import that class in my main activity?
In the nutshell, all I want to be clear about is that basically how can I use the utility class in my Main Activity?
I've got a common use-case wherein a user selects one item out of many (say, on a spinner or autocomplete list), then enters the data. For example, let's say the user selects a country. Ultimately, the data I want is the country code, not the country name; but the users will want to select based on name, not code. To put it another way, user's will select "United States", but I ultimately want that to translate into "US".
There are a lot of countries. Is there an easy way to setup a mapping in Android to hash from the name to the code? I've thought of a few solutions, none of them are quite satisfactory in my mind:
A database containing country/code, which I can query on. Setting up all countries as strings in strings.xml, then retrieving the resource by name. Creating a huge Map in code and using that. (This is the least satisfactory answer).
Find a lib which can provide url parsing/building functionality which can be used with Android platform. Character escaping is desired.
View 1 Replies View RelatedI am trying to use the SDK's DDMS utility to capture screens off my Droid X. I have installed the Java JDK and the Android SDK. I set up the USB driver on my Windows laptop and connected my Droid X to the USB port. Windows XP can see the Droid just fine in Windows Explorer as a removable USB device, but the DDMS utility shows no devices. Running "adb devices" in a DOS window lists no devices either. Yes, the java.exe location has been added to my PATH. Yes, the Droid is set to allow USB debugging. So why can't DDMS see my phone?
View 2 Replies View RelatedI'm conceptualizing an app that would *ideally* service as dashboard admin of the users SD Card. Is it possible to create a utility app that would be act as a file browser/manager for all the media on an SD Card? does this app already exist? In the event this is possible. I'm interested in sourcing a freelance developer help that can make this happen.
View 2 Replies View RelatedI am new to Java and I referred regarding my question on the Net but not quite Satisfied. I want to know what the "Utility Class" in Java is?
View 3 Replies View RelatedDuring the installation of my Android SDK, I am getting stuck during the process where the manager goes out and downloads all the revisions of the APIs and the SDKs.
It is potentially due to a socket issue that typically occurs when a database query is called and there are a large number of TCP connections... according to googling my error (No buffer space available (maximum connections reached?): recv failed )...
So I just need to know if there is a way, other then using the Android download manager, to download / update my computer with the following Android SDK components:
Downloading Documentation for Android SDK, API 7, revision 1
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 2.1, API 7, revision 1
No buffer space available (maximum connections reached?): recv failed
Skipping 'Google APIs by Google Inc., Android API 7, revision 1'; it depends on 'SDK Platform Android 2.1, API 7, revision 1' which was not installed.
Downloading Google APIs by Google Inc., Android API 7, revision 1
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 2.0.1, API 6, revision 1
No buffer space available (maximum connections reached?): recv failed
Skipping 'Google APIs by Google Inc., Android API 6, revision 1'; it depends on 'SDK Platform Android 2.0.1, API 6, revision 1' which was not installed.
Downloading Google APIs by Google Inc., Android API 6, revision 1
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 2.0, API 5, revision 1
No buffer space available (maximum connections reached?): recv failed
Skipping 'Google APIs by Google Inc., Android API 5, revision 1'; it depends on 'SDK Platform Android 2.0, API 5, revision 1' which was not installed.
Downloading Google APIs by Google Inc., Android API 5, revision 1
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 1.6, API 4, revision 2
No buffer space available (maximum connections reached?): recv failed
Skipping 'Google APIs by Google Inc., Android API 4, revision 2'; it depends on 'SDK Platform Android 1.6, API 4, revision 2' which was not installed.
Downloading Google APIs by Google Inc., Android API 4, revision 2
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 1.5, API 3, revision 3
No buffer space available (maximum connections reached?): recv failed
Skipping 'Google APIs by Google Inc., Android API 3, revision 3'; it depends on 'SDK Platform Android 1.5, API 3, revision 3' which was not installed.
Downloading Google APIs by Google Inc., Android API 3, revision 3
No buffer space available (maximum connections reached?): recv failed
Downloading SDK Platform Android 1.1, API 2, revision 1
No buffer space available (maximum connections reached?): recv failed
Downloading Usb Driver package, revision 3
No buffer space available (maximum connections reached?): recv failed
I can not find any utility to parse the ini file in android.
View 11 Replies View RelatedI'm creating a new class, using eclipse "New Java Class" dialog box. I can write the superclass I want (I can't find using "browse" button), but I can't write or select an interface to implement. I click "add" but ther is nothing to select. What I'm doing wrong?
View 4 Replies View RelatedI'm just getting into Android development, and I have a question about communicating between a receiver class and an activity class. I'm very new to JAVA and Android so I hope I don't sound too stupid. I'm developing an application where I intercept an SMS message and then based on various elements of that SMS I might delete it once it's been saved to the inbox. I have a receiver class that intercepts the txt message, and I am also able to delete messages from my inbox with code in the activity class using a button at the moment. The problem I have is communicating between the receiver class and the activity class where the code to delete a message resides. I tried putting that code directly into the receiver class but as I'm sure most of you already know the BroadcastReceiver class doesn't seem to support what I need to delete messages. I've been searching for an answer to this for a while, but haven't been able to find anything. Honestly I'm not sure I know enough about JAVA and Android to even recognize a solution if I saw it.
View 2 Replies View RelatedWhat I want to do, is be able to access the object neoApi inside the Neoseeker class, from its inner class RunningTimer. Now, in my code, you can see what I would think to work, but when I run my application, nothing pops up. Nothing inside my TextView, no Toast, nothing at all. How can I remedy this?
package com.neoseeker.android.app;
import java.util.Timer;
import java.util.TimerTask;
import org.json.JSONObject;
import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;.......................
I'm new to Java and android development. In my application I need data which is accessible for a few activities. I've read that a good solution is to use Application class for this. So I use it like this:
public class MyApplication extends Application {
private String str;
public String getStr(){
return str;
}
public void setStr(String s){
str = s;
}
}
and I can access this variable from activity like this:........................................
I have just started android. I just want to know that how can i call activity class from other java class. i just want to pass class object to activity class.
public class GsonParser extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
MagazineThread thread=new MagazineThread();
thread.start();
}
public GsonParser(JsonMagazineParser Obj)
{
}
}
and i am just doing like from other class. GsonParser obj=new GsonParser(this);passing obj to activity class.how can i achieve that.
I am doing Android programing with Eclipse (Helios), and I have some utility classes created. How do I set up Eclipse, so that if I use one of my utility classes it gets included when the project compiles?
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