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  • Database layout tagging system

    - by Kurresmack
    I am creating a web site for a customer and they want to be able to create articles. My idea is to tag them so I am going to implement the system. What is the best design, both from an architectural and a perfomance perspective: 1. To have table with all tags and then have a one to many relationship table that links a tag like this: articles table with ID tags table with ID one to many table with columns Article.ID and Tags.ID 2. To have one table with articles and one with tags for articles like this: articles table with ID tags table with Article.ID and tag text Thanks in advance!

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  • javax.naming.NameNotFoundException: Name [comp/env] is not bound in this Context. Unable to find [comp] error with java scheduler

    - by Morgan Azhari
    What I'm trying to do is to update my database after a period of time. So I'm using java scheduler and connection pooling. I don't know why but my code only working once. It will print: init success success javax.naming.NameNotFoundException: Name [comp/env] is not bound in this Context. Unable to find [comp]. at org.apache.naming.NamingContext.lookup(NamingContext.java:820) at org.apache.naming.NamingContext.lookup(NamingContext.java:168) at org.apache.naming.SelectorContext.lookup(SelectorContext.java:158) at javax.naming.InitialContext.lookup(InitialContext.java:411) at test.Pool.main(Pool.java:25) ---> line 25 is Context envContext = (Context)initialContext.lookup("java:/comp/env"); I don't know why it only works once. I already test it if I didn't running it without java scheduler and it works fine. No error whatsoerver. Don't know why i get this error if I running it using scheduler. Hope someone can help me. My connection pooling code: public class Pool { public DataSource main() { try { InitialContext initialContext = new InitialContext(); Context envContext = (Context)initialContext.lookup("java:/comp/env"); DataSource datasource = new DataSource(); datasource = (DataSource)envContext.lookup("jdbc/test"); return datasource; } catch (Exception ex) { ex.printStackTrace(); } return null; } } my web.xml: <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <listener> <listener-class> package.test.Pool</listener-class> </listener> <resource-ref> <description>DB Connection Pooling</description> <res-ref-name>jdbc/test</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> </resource-ref> Context.xml: <?xml version="1.0" encoding="UTF-8"?> <Context path="/project" reloadable="true"> <Resource auth="Container" defaultReadOnly="false" driverClassName="com.mysql.jdbc.Driver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" initialSize="0" jdbcInterceptors="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer" jmxEnabled="true" logAbandoned="true" maxActive="300" maxIdle="50" maxWait="10000" minEvictableIdleTimeMillis="300000" minIdle="30" name="jdbc/test" password="test" removeAbandoned="true" removeAbandonedTimeout="60" testOnBorrow="true" testOnReturn="false" testWhileIdle="true" timeBetweenEvictionRunsMillis="30000" type="javax.sql.DataSource" url="jdbc:mysql://localhost:3306/database?noAccessToProcedureBodies=true" username="root" validationInterval="30000" validationQuery="SELECT 1"/> </Context> my java scheduler public class Scheduler extends HttpServlet{ public void init() throws ServletException { System.out.println("init success"); try{ Scheduling_test test = new Scheduling_test(); ScheduledExecutorService executor = Executors.newScheduledThreadPool(100); ScheduledFuture future = executor.scheduleWithFixedDelay(test, 1, 60 ,TimeUnit.SECONDS); }catch(Exception e){ e.printStackTrace(); } } } Schedule_test public class Scheduling_test extends Thread implements Runnable{ public void run(){ Updating updating = new Updating(); updating.run(); } } updating public class Updating{ public void run(){ ResultSet rs = null; PreparedStatement p = null; StringBuilder sb = new StringBuilder(); Pool pool = new Pool(); Connection con = null; DataSource datasource = null; try{ datasource = pool.main(); con=datasource.getConnection(); sb.append("SELECT * FROM database"); p = con.prepareStatement(sb.toString()); rs = p.executeQuery(); rs.close(); con.close(); p.close(); datasource.close(); System.out.println("success"); }catch (Exception e){ e.printStackTrace(); } }

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  • Ruby on Rails: How to find all items with a hash that contain a specific value...

    - by kingjeffrey
    Suppose I have three models: Student, SchoolClass, and DayOfWeek. There is a HABTM relationship between Student and SchoolClass, and between SchoolClass and DayOfWeek. What I'd like to do is find all school classes belonging to a given student that meet on Monday. Now I suppose I could do something like: @student = Student.find(:student_id) @student_classes = @student.school_classes.find(:all) @student_classes_on_monday = Array.new @student_classes.each do |student_class| if student_class.day_of_week.include?("Monday") @student_classes_on_monday << student_class end end But there has to be a more elegant way. Can you help me find it?

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  • Android app hanging, sometimes until Force Close / Wait dialog appears

    - by fredley
    I'm making an app that records uncompressed (wav format) audio. I'm using this class to actually record the audio. Currently, my application records fine (I can play the file), however when I click the button to stop the recording, the app hangs for 10 seconds or so, with no log output or any signs of life. Finally it comes round, dumps a load of errors into the log, updates the UI etc. I'm using AsyncTasks to try and avoid this kind of thing but it's not working. Here's my code: //Called on clicks of the record button. rar is the instance of RehearsalAudioRecorder private OnClickListener RecordListener = new OnClickListener(){ @Override public void onClick(View v) { Log.d("Record","Click"); if (recording){ new stopRecordingTask().execute(rar,null,null); startStop.setText("Record"); statusBar.setText("Recording Finished, ready to Encode"); }else{ recording = true; new startRecordingTask().execute(rar,null,null); startStop.setText("Stop"); statusBar.setText("Recording Started"); } } }; private class startRecordingTask extends AsyncTask<RehearsalAudioRecorder,Void,Void>{ @Override protected Void doInBackground(RehearsalAudioRecorder... rs) { RehearsalAudioRecorder r = rs[0]; r.setOutputFile("/sdcard/rarOut.wav"); r.prepare(); r.start(); return null; } } private class stopRecordingTask extends AsyncTask<RehearsalAudioRecorder,Void,Void>{ @Override protected Void doInBackground(RehearsalAudioRecorder... rs) { RehearsalAudioRecorder r = rs[0]; r.stop(); r.reset(); return null; } } In Logcat, I always get output like this, which has me stumped. I have no idea what's causing it (I'm logging the RehearsalAudioRecorder class, and it's being started/stopped correctly by the button clicks. This output occurs after the log output for the button click and correct stop() method call) 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: STOPPED 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: ERROR 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: ERROR ... 10 or more times I've been fiddling with this all day and I'm not getting anywhere, any input would be greatly appreciated. Update I've replace the AsyncTasks with Threads, still doesn't work, the app completely hangs when I click record, despite the fact the Log indicates there's nothing going on in the main thread. Still completely stumped.

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  • Cakephp, Retreive Data for HABTM Models using find

    - by user298079
    I am new to cakephp and I'm trying to accomplish something that should be relatively easy. I have 2 models projects & categories bind by HABTM relationship. I am trying to perform the following query - find all projects that belong to a category $projects = $this->Project->find('all', array('conditions' => array('Category.slug' => $category))); However when I'm doing so it generates an SQL error: SQL Error: 1054: Unknown column 'Category.slug' in 'where clause' What am I doing wrong??

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  • How to get data from struts2 action with jQuery?

    - by Rafa Romero
    I have an Struts2 Web with GoogleMaps. I want to load a list of markers which are saved in a SQL DDBB. To do this, I tried with jQuery and Ajax. Here you are the code: loadMarkers.java public class loadMarkers extends ActionSupport implements ServletRequestAware,ServletResponseAware{ //Variables de sesion/cookie FunctionClass ses; protected HttpServletResponse servletResponse; protected HttpServletRequest servletRequest; private String userID=""; //Variables del marker private List<marker> markersList = new ArrayList<marker>(); public String execute() throws Exception{ FunctionClass friends = new FunctionClass(); //Leemos de la cookie for(Cookie c : servletRequest.getCookies()) { if (c.getName().equals("userID")) userID = (c.getValue()); } System.out.println("en el loadMarkers"); connectionBBDD con = new connectionBBDD(); markersList = con.loadMarkers(userID); return SUCCESS; } I want to use the markerList array in Javascript, to create the markers. This is the struts.xml file: <package name="jsonActions" namespace="/test" extends="json-default"> <action name="LoadMarkers" class="web.localizadroid.maps.loadMarkers"> <interceptor-ref name="basicStack"/> <result type="json"> <param name="root">markersList</param> </result> </action> </package> And here you are the Javascript (jQuery) code: function loadMarkersJ(){ alert("dentro"); $.ajax({ type : "post", url : "LoadMarkers", dataType: "json", success : function(data) { alert(data); var image = new google.maps.MarkerImage ('http://i53.tinypic.com/ettquh.png'); var jSon_Object = eval("(" + data + ")"); //For para analizar los datos (Json) obtenidos de la BBDD for (x = 0; x < jSon_Object.length; x++) { var markersArray = []; var myLatlng = new google.maps.LatLng(jSon_Object[x].lat, jSon_Object[x].lon); markerLoaded = new google.maps.Marker( { position : myLatlng, map : map, icon: image, title: "NOMBRE: " + jSon_Object[x].tarjetName + "\n" + "ANOTACIONES: " + jSon_Object[x].anotaciones + "\n" + "TIME: " + jSon_Object[x].time }); markersArray.push(markerLoaded); if (markersArray) { for (i in markersArray) { alert("entro en forColocaMarkers"); if (markersArray[i].getAnimation() != null) { markersArray[i].setAnimation(null); } else { markersArray[i].setAnimation(google.maps.Animation.BOUNCE); } markersArray[i].setMap(map); } } } } }); } From success : function(data) { to the end, is JavaScript code to create de markers, and this it's OK. The problem is whith ajax, because I don't get to obtain markerList Array by jSon data return...I think that the problem is in the url attribute from $.ajax...I tried loadMarkers.action and loadMarkers, but nothing happens. When I execute the web, only prints the alert alert("dentro"), the alert alert(data) never has been printed. I have forgotten to add the code where I call the Javascript function (loadMarkersJ). Here you are: <p><s:a action="LoadMarkers.action" namespace="/test" onclick="loadMarkersJ(this)">Cargar Marcadores S</s:a></p> Somebody can help me please?

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  • SQL join to grab data from same table via intermediate table

    - by Sergio
    Hi Could someone help me with building the following query. I have a table called Sites, and one called Site_H. The two are joined by a foreign key relationship on page_id. So the Sites table contains pages, and the Site_H table shows which pages any given page is a child of by having another foreign key relation back to the site table with a column called ParentOf. So, a page can be have another page as a parent. Other data is stored in the Site_H table such as position etc, hence why it is separated out. I would like a query that returns the details of a page along with the details of its parent page. I just cant quite think about how to structure the SQL. Thanks

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  • Partial form with nested routes

    - by jerhinesmith
    I have two models -- User and Entry -- that are related through a has_many relationship (a User has many Entries). I'm using RESTful routing, and have the following in my routes.rb file: map.resource :user, :controller => "users" do |user| user.resources :entries end This seems to work, but in my partial _form file, when I do this: form_for [@current_user, @entry] do |f| # Form stuff end It generates a URL like this: /user/entries.%23%3Cuser:0xb6a6aea8%3E instead of /user/entries Am I missing something? I should note that the correct classes are applied to the form when doing creation vs. editing, so it does seem to be correctly interpreting what I'm trying to do -- it's just that I can't submit the form to an invalid url.

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  • How to explain to a client that you've gone over-budget and you'll need more money/time to deliver w

    - by General Tapioca
    My situation is that I have agreed on a per-project proposal with the client. The proposal is vague, but still names functionality in a way that can be argued as to whether it's included or not, while leaving some room for interpretation. I originally pressed as much as I could to get a per-month contract, arguing that the project is mostly non-predictable, but the client refused. Being a small company, I had to fold and signed a contract on an estimate based on my group's estimations. At this point we have reached completion on about 85% of the features (we think) but we ran out of budget. We have been working for almost two years with this client in previous contracts, and we have delivered a good product that they are happy with, so we have a good standing relationship. More info: -There has been a bit of scope-creep, but I don't think enough for me to hide behind that argument -We've been delivering partial releases about monthly. -We don't have systematic user-testing in place.

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  • Blackberry XML Parsing Application not working

    - by Nirmal
    Hello All... I found one sample application from the Blackberry knowledgebase. From that application I have put that sample application on my eclipse plugin, and the code is as follows : import javax.microedition.io.*; import net.rim.device.api.ui.*; import net.rim.device.api.ui.component.*; import net.rim.device.api.ui.container.*; import net.rim.device.api.system.*; import net.rim.device.api.xml.parsers.*; import org.w3c.dom.*; import org.xml.sax.*; class XML_Parsing_Sample extends UiApplication { // creating a member variable for the MainScreen MainScreen _screen = new MainScreen(); // string variables to store the values of the XML document String _node, _element; Connection _connectionthread; public static void main(String arg[]) { XML_Parsing_Sample application = new XML_Parsing_Sample(); // create a new instance of the application // and start the application on the event thread application.enterEventDispatcher(); } public XML_Parsing_Sample() { _screen.setTitle("XML Parsing");// setting title _screen.add(new RichTextField("Requesting.....")); _screen.add(new SeparatorField()); pushScreen(_screen); // creating a screen // creating a connection thread to run in the background _connectionthread = new Connection(); _connectionthread.start();// starting the thread operation } public void updateField(String node, String element) { // receiving the parsed node and its value from the thread // and updating it here // so it can be displayed on the screen String title = "My App"; _screen.add(new RichTextField(node + " : " + element)); if (node.equals(title)) { _screen.add(new SeparatorField()); } } private class Connection extends Thread { public Connection() { super(); } public void run() { // define variables later used for parsing Document doc; StreamConnection conn; try { // providing the location of the XML file, // your address might be different conn = (StreamConnection) Connector .open("http://www.sufalamtech.com/demo/moviewebservice/Test.xml"); // next few lines creates variables to open a // stream, parse it, collect XML data and // extract the data which is required. // In this case they are elements, // node and the values of an element DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder docBuilder = docBuilderFactory .newDocumentBuilder(); docBuilder.isValidating(); doc = docBuilder.parse(conn.openInputStream()); doc.getDocumentElement().normalize(); NodeList list = doc.getElementsByTagName("*"); _node = new String(); _element = new String(); // this "for" loop is used to parse through the // XML document and extract all elements and their // value, so they can be displayed on the device for (int i = 0; i < list.getLength(); i++) { Node value = list.item(i).getChildNodes().item(0); _node = list.item(i).getNodeName(); _element = value.getNodeValue(); updateField(_node, _element); }// end for }// end try // will catch any exception thrown by the XML parser catch (Exception e) { Dialog.alert("exception = " + e); } }// end connection function }// end connection class }// end XML_Parsing_Sample But when I am running this application, the simulator just showing me a Blank screen with label Requesting... Anybody help me out for this ? Thanks in advance...

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  • Java MapReduce read data

    - by Tatiana
    Hi I am having following map-reduce code by which I am trying to read records from my database. There's code: import java.io.*; import java.util.ArrayList; import java.util.List; import org.apache.hadoop.fs.*; import org.apache.hadoop.io.*; import org.apache.hadoop.mapred.*; import org.apache.hadoop.mapred.lib.db.DBConfiguration; import org.apache.hadoop.mapred.lib.db.DBInputFormat; import org.apache.hadoop.mapred.lib.db.DBWritable; import org.apache.hadoop.util.*; import org.apache.hadoop.conf.*; public class Connection extends Configured implements Tool { public int run(String[] args) throws IOException { JobConf conf = new JobConf(getConf(), Connection.class); conf.setInputFormat(DBInputFormat.class); DBConfiguration.configureDB(conf, "com.sun.java.util.jar.pack.Driver", "jdbc:postgresql://localhost:5432/polyclinic", "postgres", "12345"); String[] fields = { "name" }; DBInputFormat.setInput(conf, MyRecord.class, "doctors", null, null, fields); conf.setMapOutputKeyClass(LongWritable.class); conf.setMapOutputValueClass(MyRecord.class); conf.setOutputKeyClass(LongWritable.class); conf.setOutputValueClass(TextOutputFormat.class); TextOutputFormat.setOutputPath(conf, new Path(args[0])); JobClient.runJob(conf); return 0; } public static void main(String[] args) throws Exception { int exitCode = ToolRunner.run(new Connection(), args); System.exit(exitCode); } } Class Mapper: import java.io.IOException; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapred.MapReduceBase; import org.apache.hadoop.mapred.Mapper; import org.apache.hadoop.mapred.OutputCollector; import org.apache.hadoop.mapred.Reporter; public class MyMapper extends MapReduceBase implements Mapper<LongWritable, MyRecord, Text, IntWritable> { public void map(LongWritable key, MyRecord val, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException { output.collect(new Text(val.name), new IntWritable(1)); } } Class Record: import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.Writable; import org.apache.hadoop.mapred.lib.db.DBWritable; class MyRecord implements Writable, DBWritable { String name; public void readFields(DataInput in) throws IOException { this.name = Text.readString(in); } public void readFields(ResultSet resultSet) throws SQLException { this.name = resultSet.getString(1); } public void write(DataOutput out) throws IOException { } public void write(PreparedStatement stmt) throws SQLException { } } After this I got error: WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String). Can you give me any suggestion how to solve this problem?

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  • to-many Core Data fetch request behaves oddly with a new store

    - by Giao
    I have two entities, Department and Person. Department has a to-many relationship to Person. The Person entity has a hireDate property. I'm using the predicate "count(person) = 0 OR none person.hireDate %@" to find Departments without any Persons in them or Departments that haven't hired anyone since a recent date. When the app first starts up (new user experience) and Departments are inserted and no Person have been inserted, the fetch request with this predicate returns nothing. However, if I create insert a new Person entity and delete it, then save the store, the fetch request will return all the Departments. I've found a work around where, I just insert a new Person and delete it, then save the store, the fetch request as I expected it to work. I've found that inserting a new Person and deleting it without saving will not correct the problem. Is this a bug with Core Data or is this a bug with how I've designed my app?

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  • NullPointerException using EndlessAdapter with SimpleAdapter

    - by android_dev
    Hello, I am using EndlessAdapter from commonsguy with a SimpleAdapter. I can load data when I make a scroll down without problems, but I have a NullPointerException when I make a scroll up. The problem is in the method @Override public View getView(int position, View convertView,ViewGroup parent) { return wrapped.getView(position, convertView, parent); } from the class AdapterWrapper. The call to wrapped.getView(position, convertView,parent) raises the exception and I don´t know why. This is my implementation of EndlessAdapter: //Inner class in SearchTextActivity class DemoAdapter extends EndlessAdapter { private RotateAnimation rotate = null; DemoAdapter(ArrayList<HashMap<String, String>> result) { super(new SimpleAdapter(SearchTracksActivity.this, result, R.layout.textlist_item, PROJECTION_COLUMNS, VIEW_MAPPINGS)); rotate = new RotateAnimation( 0f, 360f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); rotate.setDuration(600); rotate.setRepeatMode(Animation.RESTART); rotate.setRepeatCount(Animation.INFINITE); } @Override protected View getPendingView(ViewGroup parent) { View row=getLayoutInflater().inflate(R.layout.textlist_item, null); View child=row.findViewById(R.id.title); child.setVisibility(View.GONE); child=row.findViewById(R.id.username); child.setVisibility(View.GONE); child=row.findViewById(R.id.throbber); child.setVisibility(View.VISIBLE); child.startAnimation(rotate); return row; } @Override @SuppressWarnings("unchecked") protected void rebindPendingView(int position, View row) { HashMap<String, String> res = (HashMap<String, String>)getWrappedAdapter().getItem(position); View child=row.findViewById(R.id.title); ((TextView)child).setText(res.get("title")); child.setVisibility(View.VISIBLE); child=row.findViewById(R.id.username); ((TextView)child).setText(res.get("username")); child.setVisibility(View.VISIBLE); ImageView throbber=(ImageView)row.findViewById(R.id.throbber); throbber.setVisibility(View.GONE); throbber.clearAnimation(); } boolean mFinal = true; @Override protected boolean cacheInBackground() { EditText searchText = (EditText)findViewById(R.id.searchText); String textToSearch = searchText.getText().toString(); Util.getSc().searchText(textToSearch , offset, limit, new ResultListener<ArrayList<Text>>() { @Override public void onError(Exception e) { e.toString(); mFinal = false; } @Override public void onSuccess(ArrayList<Text> result) { if(result.size() == 0){ mFinal = false; }else{ texts.addAll(result); offset++; } } }); return mFinal; } @Override protected void appendCachedData() { for(Text text : texts){ result.add(text.getMapValues()); } texts.clear(); } } And I use it this way: public class SearchTextActivity extends AbstractListActivity { private static final String[] PROJECTION_COLUMNS = new String[] { TextStore.Text.TITLE, TextStore.Text.USER_NAME}; private static final int[] VIEW_MAPPINGS = new int[] { R.id.Text_title, R.id.Text_username}; ArrayList<HashMap<String, String>> result; static ArrayList<Text> texts; static int offset = 0; static int limit = 1; @Override void onAbstractCreate(Bundle savedInstance) { setContentView(R.layout.search_tracks); setupViews(); } private void setupViews() { ImageButton searchButton = (ImageButton)findViewById(R.id.searchButton); updateView(); } SimpleAdapter adapter; void updateView(){ if(result == null) { result = new ArrayList<HashMap<String, String>>(); } if(tracks == null) { texts = new ArrayList<Text>(); } } public void sendQuery(View v){ offset = 0; texts.clear(); result.clear(); setListAdapter(new DemoAdapter(result)); } } Does anybody knows what could be the problem? Thank you in advance

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  • Parallel processing via multithreading in Java

    - by Robz
    There are certain algorithms whose running time can decrease significantly when one divides up a task and gets each part done in parallel. One of these algorithms is merge sort, where a list is divided into infinitesimally smaller parts and then recombined in a sorted order. I decided to do an experiment to test whether or not I could I increase the speed of this sort by using multiple threads. I am running the following functions in Java on a Quad-Core Dell with Windows Vista. One function (the control case) is simply recursive: // x is an array of N elements in random order public int[] mergeSort(int[] x) { if (x.length == 1) return x; // Dividing the array in half int[] a = new int[x.length/2]; int[] b = new int[x.length/2+((x.length%2 == 1)?1:0)]; for(int i = 0; i < x.length/2; i++) a[i] = x[i]; for(int i = 0; i < x.length/2+((x.length%2 == 1)?1:0); i++) b[i] = x[i+x.length/2]; // Sending them off to continue being divided mergeSort(a); mergeSort(b); // Recombining the two arrays int ia = 0, ib = 0, i = 0; while(ia != a.length || ib != b.length) { if (ia == a.length) { x[i] = b[ib]; ib++; } else if (ib == b.length) { x[i] = a[ia]; ia++; } else if (a[ia] < b[ib]) { x[i] = a[ia]; ia++; } else { x[i] = b[ib]; ib++; } i++; } return x; } The other is in the 'run' function of a class that extends thread, and recursively creates two new threads each time it is called: public class Merger extends Thread { int[] x; boolean finished; public Merger(int[] x) { this.x = x; } public void run() { if (x.length == 1) { finished = true; return; } // Divide the array in half int[] a = new int[x.length/2]; int[] b = new int[x.length/2+((x.length%2 == 1)?1:0)]; for(int i = 0; i < x.length/2; i++) a[i] = x[i]; for(int i = 0; i < x.length/2+((x.length%2 == 1)?1:0); i++) b[i] = x[i+x.length/2]; // Begin two threads to continue to divide the array Merger ma = new Merger(a); ma.run(); Merger mb = new Merger(b); mb.run(); // Wait for the two other threads to finish while(!ma.finished || !mb.finished) ; // Recombine the two arrays int ia = 0, ib = 0, i = 0; while(ia != a.length || ib != b.length) { if (ia == a.length) { x[i] = b[ib]; ib++; } else if (ib == b.length) { x[i] = a[ia]; ia++; } else if (a[ia] < b[ib]) { x[i] = a[ia]; ia++; } else { x[i] = b[ib]; ib++; } i++; } finished = true; } } It turns out that function that does not use multithreading actually runs faster. Why? Does the operating system and the java virtual machine not "communicate" effectively enough to place the different threads on different cores? Or am I missing something obvious?

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  • Star schema [fact 1:n dimension]...how?

    - by Mike Gates
    I am a newcomer to data warehouses and have what I hope is an easy question about building a star schema: If I have a fact table where a fact record naturally has a one-to-many relationship with a single dimension, how can a star schema be modeled to support this? For example: Fact Table: Point of Sale entry (the measurement is DollarAmount) Dimension Table: Promotions (these are sales promotions in effect when a sale was made) The situation is that I want a single Point Of Sale entry to be associated with multiple different Promotions. These Promotions cannot be their own dimensions as there are many many many promotions. How do I do this?

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  • Using a RegEx in a SQL Query

    - by Jim B
    Hey Everyone, Here's the situation I'm in: We have a field in our database that contains a 3 digit number, surrounded by some text. This number is actually a PK in another table, and I need to extract this out so I can implement a proper FK relationship. Here's an example of what would currently reside in the column: Some Text Goes Here - (305) Followed By Some More Text So, what I'm looking to do is extract the '305' from the column, and hopefully end up with a result that looks something like this (pseudo code) SELECT <My Extracted Value>, Original Column Text, Id FROM dbo.MyTable It seems to me that using a Regex match in my query is the most effective way to do this. Can anybody point me in the right direction?

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  • Rails find_or_create by more than one attribute?

    - by tybro0103
    There is a handy dynamic attribute in active-record called find_or_create_by: Model.find_or_create_by_<attribute>(:<attribute> => "") But what if I need to find_or_create by more than one attribute? Say I have a model to handle a M:M relationship between Group and Member called GroupMember. I could have many instances where member_id = 4, but I don't ever want more than once instance where member_id = 4 and group_id = 7. I'm trying to figure out if it's possible to do something like this: GroupMember.find_or_create(:member_id => 4, :group_id => 7) I realize there may be better ways to handle this, but I like the convenience of the idea of find_or_create.

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  • How to order the items in a nested LINQ-provided collection

    - by Carson McComas
    I've got a (SQL Server) database table called Category. And another database table called SubCategory. SubCategory has a foreign key relationship to Category. Because of this, thanks to LINQ, each Cateogory has a property called SubCategories and LINQ is nice enough to return all the SubCategories associated with my Category when I grab it. If I want to sort the Categories alphabetically, I can just do: return db.Categories.OrderBy(c => c.Name); However, I have no idea how to order the SubCategories collection inside each Category. My goal is to return a collection of Categories, where all of the SubCategory collections inside of them are ordered alphabetically by Name.

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  • Objective-C Custom extend

    - by ryanjm.mp
    I have a couple classes that have nearly identical code. Only a string or two is different between them. What I would like to do is to make them from another class that defines those functions and then uses constants or something else to define those strings that are different. I'm not sure if "___" is inheritance or extending or what. That is what I need help with. For example: objectA.m: -(void)helloWorld { NSLog("Hello %@",child.name); } objectBob.m: #define name @"Bob" objectJoe.m #define name @"Joe" (I'm not sure if it's legal to define strings, but this gets the point across) It would be ideal if objectBob.m and objectJoe.m didn't have to even define the methods, just their relationship to objectA.m. Is there any way to do something like this? If all else fails I'll just make objectA.m: -(void)helloWorld:(NSString *name) { NSLog("Hello %@",name); } And have the other files call that function (and just #import objectA.m).

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  • sql server 2005 - return single row when 2 records in right table

    - by Peanut
    Hi, I have two related sql server tables ... TableA and TableB. ***TableA - Columns*** TableA_ID INT VALUE VARCHAR(100) ***TableB - Columns*** TableB_ID INT TableA_ID INT VALUE VARCHAR(100) For every single record in TableA there are always 2 records in TableB. Therefore TableA has a one-to-many relationship with TableB. How could I write a single sql statement to join these tables and return a single row for each row in TableA that includes: a column for the VALUE column in the first related row in table B a column for the VALUE column in the second related row in table B? Thanks.

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  • Quering distinct values throught related model

    - by matheus.emm
    Hi! I have a simple one-to-many (models.ForeignKey) relationship between two of my model classes: class TeacherAssignment(models.Model): # ... some fields year = models.CharField(max_length=4) class LessonPlan(models.Model): teacher_assignment = models.ForeignKey(TeacherAssignment) # ... other fields I'd like to query my database to get the set of distinct years of TeacherAssignments related to at least one LessonPlan. I'm able to get this set using Django query API if I ignore the relation to LessonPlan: class TeacherAssignment(models.Model): # ... model's fields def get_years(self): year_values = self.objects.all().values_list('year').distinct().order_by('-year') return [yv[0] for yv in year_values if len(yv[0]) == 4] Unfortunately I don't know how to express the condition that the TeacherAssignment must be related to at least one LessonPlan. Any ideas how I'd be able to write the query? Thanks in advance.

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  • Using STI path with same controller

    - by TenJack
    I am using STI and am wondering, do I have to have a separate controller for each model? I have a situation where I only use the create and edit actions for one model in the STI relationship, but I get an 'undefined method' error if I try to do a form for. More specifically, I have two models that inherit from List: class RegularList < List class OtherList < List and I have a lists controller that handles these actions, but I only create new models with RegularList using forms. i.e. the only situation where I use a form_for to create a new List object is with RegularList. What I would like to do is something like: class ListsController < ApplicationController def new @list = RegularList.new end otherwise the route for creating a new list looks like regular_list/new but I would like it to just be list/new. Thoughts?

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  • How to catch specific exception without error number?

    - by CJ7
    I need to catch the following specific exception: System.Data.OleDb.OleDbException was caught ErrorCode=-2147467259 Message="The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries and try again." Source="Microsoft JET Database Engine" I'm not sure what ErrorCode is but it looks unreliable. Can I rely on Message being identical across platforms? Is the only solution to do a text search of Message for words like duplicate and primary key? Note: see my question here for why I need to catch this exception.

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  • GoogleTv video using VideoView is clipped, even though its in a separate layout of its own

    - by MYR
    Wrote an application for GoogleTV box to play a video. The video is a separate activity to the main activity. Wired up a button on my main layout/activity to to start the video activity up (using its own video.xml layout), the video activity loads and starts playing, but the video is clipped, only showing a few centimetres of the bottom. The clipped region looks like the views that occupied the previous layout (main.xml) . The intriguing thing is that if I push the back button, before returning to the main activity the full video frame is shown. Not sure what I am doing wrong here. Any suggestions welcome. Code: main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TextView android:id="@+id/hello_message" android:layout_width="fill_parent" android:layout_height="200dp" android:gravity="center" android:text="@string/hello_message" android:textSize="78sp" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" > <EditText android:id="@+id/edit_message" android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:ems="10" android:hint="@string/edit_message" > <requestFocus /> </EditText> <Button android:id="@+id/button_send" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="displayMessage" android:text="@string/button_send" /> <Button android:id="@+id/button_send_a" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="sendMesssage" android:text="@string/button_send_a" /> </LinearLayout> <Button android:id="@+id/videobutton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="startAVideo" android:text="Video Player" /> </LinearLayout> GoogleTVExActivity.java (excerpt): ... public class GoogleTVExActivity extends Activity { public final static String EXTRA_MESSAGE = "uk.co.bbc.googletvex.MESSAGE"; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } public void displayMessage(View view) { TextView t = (TextView)findViewById(R.id.hello_message); EditText e =(EditText) findViewById(R.id.edit_message); t.setText(e.getText().toString()); e.setText(""); } public void sendMesssage(View view) { Intent intent = new Intent(this, DisplayMessageActivity.class); EditText editText = (EditText) findViewById(R.id.edit_message); String message = editText.getText().toString(); intent.putExtra(EXTRA_MESSAGE, message); startActivity(intent); } public void startAVideo(View view) { Intent intent = new Intent(this, VideoViewActivity.class); startActivity(intent); } } video.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <VideoView android:id="@+id/myvideoview" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout> VideoViewActivity.java (excerpt) ... import android.app.Activity; import android.net.Uri; import android.os.Bundle; import android.widget.MediaController; import android.widget.VideoView; public class VideoViewActivity extends Activity { String SrcPath = "rtsp://v5.cache1.c.youtube.com/CjYLENy73wIaLQnhycnrJQ8qmRMYESARFEIJbXYtZ29vZ2xlSARSBXdhdGNoYPj_hYjnq6uUTQw=/0/0/0/video.3gp"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.video); VideoView myVideoView = (VideoView)findViewById(R.id.myvideoview); myVideoView.setVideoURI(Uri.parse(SrcPath)); myVideoView.setMediaController(new MediaController(this)); myVideoView.requestFocus(); myVideoView.start(); } }

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  • Django show manytomanyfield on form when definition is on other model

    - by John
    Hi I have the definition for my manytomany relationship on one model but want to display the field on a form for the other model. How do I do this? for example: # classes class modelA(models.Model): name = models.CharField(max_length=300) manytomany = models.ManyToManyField(modelA) class modelB(models.Model): name = models.CharField(max_length=300) # forms class modelBForm(forms.ModelForm): class Meta: model = modelB I want to use the form modelBForm but show a select box with a list from modelA (just how it would work if the model was set to modelA in the form class). How can I do this? Thanks

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