Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 875/1332 | < Previous Page | 871 872 873 874 875 876 877 878 879 880 881 882  | Next Page >

  • Is it a good idea to close and open hibernate sessions frequently?

    - by Gaurav
    Hi, I'm developing an application which requires that state of entities be read from a database at frequent intervals or triggers. However, once hibernate reads the state, it doesn't re-read it unless I explicitly close the session and read the entity in a new session. Is it a good idea to open a session everytime I want to read the entity and then close it afterwards? How much of an overhead does this put on the application and the database (we use a c3p0 connection pool also)? Will it be enough to simply evict the entity from the session before reading it again?

    Read the article

  • Compare class objects

    - by reto
    I have to compare a class object against a list of pre defined classes. Is it safe to use == or should I use equals()? if (klass == KlassA.class) { } else if (klass == KlassB.class) { } else if (klass == KlassC.class) { } else { } Note: I cannot use instanceof, I don't have an object, I just have the class object. I (mis)use it like an enum in this situation! Thanks!

    Read the article

  • Where to store Android preference keys?

    - by pixel
    When I create preference activity I define all preferences in xml file. Every preference has a key defined in this xml. But when I access preference I write: SharedPreferences appPreferences = PreferenceManager.getDefaultSharedPreferences(this); boolean foo_value = appPreferences.getBoolean("foo_key_defined_in_xml", false); Is there any way to avoid acessing "foo_key_defined_in_xml" in hard-coded way? Maybe there is a possibility to access it in R style way?

    Read the article

  • Weird parsing date string error in Android 2.0 emulator

    - by kknight
    I have a simple test code for testing SimpleDateFormat. This code works well on Eclipse and Android 1.5 emulator, but it failed at Android 2.0 emulator. Does anyone know why? Thanks. public class TemplateActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); TextView tv = new TextView(this); tv.setText(R.string.hello); setContentView(tv); SimpleDateFormat format = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz"); String dateStr = "Mon, 17 May 2010 01:45:41 GMT"; try { Date parsed = format.parse(dateStr); Log.v("Test", parsed.toString()); } catch (ParseException pe) { Log.v("Test", "ERROR: Cannot parse \"" + dateStr + "\""); } } } Log message: V/Test( 400): ERROR: Cannot parse "Mon, 17 May 2010 01:45:41 GMT"

    Read the article

  • NullPointerException when adding to BigDecimal

    - by Dan
    String[] toppings = new String[10]; BigDecimal toppingsPrice = null; toppings[0] = req.getParameter("extraCheese"); toppings[1] = req.getParameter("moreTomatoes"); toppings[2] = req.getParameter("extraOnions"); // ... for(int i = 0; i < toppings.length; i++) { if(toppings[i] != null) { toppingsPrice.add(new BigDecimal("0.99")); // <-- NPE is caused here. toppingsPrice = toppingsPrice.setScale(2, BigDecimal.ROUND_HALF_EVEN); } } I am getting a NullPointerException in the above code when adding 0.99 to toppingsPrice. I am working with money values, so I have used BigDecimal. Is there something wrong with how I am adding the 0.99c price?

    Read the article

  • Which faces technology for use with GlassFish 2.1 and NetBeans 6.7?

    - by SteJav
    I'm running GlassFish 2.1 and using NetBeans 6.7. I'd like to create a web interface to my data using JSF 1.2. Trouble is, I'm not sure which 'faces' technology to learn (that includes some good documentation). JBoss/RichFaces seem pretty good on documentation, but I'm using GlassFish. Any thoughts? The choices appear overwhelming: Tomahawk Tobago Trinidad ICEfaces RCFaces Netadvantage WebGalileoFaces QuipuKit BluePrints Woodstock JBoss RichFaces Ajax4jsf ILOG Oracle ADF G4JSF Simplica Backbase jenia4faces VisualWebPack DynaFaces IBM Impl Dinamica Mojarra PrimeFaces jQuery OpenFaces ZK ExtJS Anybody had any experience with any of the above and found the documentation to be clear to a beginner? Being a JSF/Web beginner, I tried some ICEFaces, Mojarra tutorials and had a go at getting RichFaces working with NBeans and GlassFish, but no luck. Lots of XML complaints. I'm clearly missing some huge chunks of configuration, but I can't find any documentation to help me. Any suggestions would be much appreciated :-)

    Read the article

  • Can fields of the class and arguments of the method interfere?

    - by Roman
    I have a class with a fields called "a". In the class I have a method and in the list of arguments of this method I also have "a". So, which "a" I will see inside of the method? Will it be the field or it will be the argument of the method? public class myClass { private String a; // Method which sets the value of the field "a". public void setA(String a) { a = a; } } By the way, there is a similar situation. A method has some local (for method) variables whose names coincide with the names of the fields. What will the "see" the method if I refer to such a method-local variable inside the method (the field or the local variable)?

    Read the article

  • can't understand the url function used in the google taskque api documentation

    - by Bunny Rabbit
    import com.google.appengine.api.labs.taskqueue.Queue; import com.google.appengine.api.labs.taskqueue.QueueFactory; import static com.google.appengine.api.labs.taskqueue.TaskOptions.Builder.*; // ... Queue queue = QueueFactory.getDefaultQueue(); queue.add(url("/worker").param("key", key)) in the code example given on the google task queue documentation page i can't understand the url("/worker") function they are calling in the queues.add() invocation .

    Read the article

  • Two collections manyToOne to same primary key

    - by Ethiel
    Hi, guys, I'm coding a web page in Hibernate-JPA and Oracle. I need the following: I have two classes: Place and Home. I need two collections of type Place in every Home: I do the following: Home: @ManyToOne @JoinColumn(name="ID_PLACES") private List<Places>places1; @ManyToOne @JoinColumn(name="ID_PLACES") private List<Places>Places2; However, hibernate got an exception (repeated column) and forces to me to mapping with insert and update to false. How Can I get Two ManyToOne relationship to same primary key with insert a true?.

    Read the article

  • user enter data to different arrays

    - by user2900469
    This is fragment of my code (arrays as you can see): double[] Price; String[] names; int[] Quantity; Price = new double[5]; names = new String[5]; Quantity = new int[5]; Price[1] = 3.10; Price[2] = 7.80; Price[3] = 0.20; names[1] = "Ballpen"; names[2] = "Notebook"; names[3] = "Envelope"; Quantity[1] = 20; Quantity[2] = 5; Quantity[3] = 140; I enter data to arrays by myself in this case. Now i want to change my code so that my program asks user for names, price and quantity (using the Scanner class). After user enter data, program keep this in three different arrays. I dont know how to transfer data from user to arrays. I would be grateful for some example code or any help.

    Read the article

  • Hibernate Exception Fixed By Alt+Tab

    - by Lee Theobald
    Hi all, I've got a very curious problem in Hibernate that I would like some opinions on. In my code if I do the following: Go to page A Click a link on page A to be taken to page B Click on data item on page B Exception thrown I get an error telling me: failed to lazily initialize a collection of role: XYZ, no session or session was closed Fair enough. But when I do the same thing but add an alt+tab in the middle, everything is fine. E.g. Go to page A Click a link on page A to be taken to page B Hit ALt+Tab to switch to another application Hit ALt+Tab to switch back to the web browser Click on data item on page B Everything is fine. I'm a little confused as to how switching focus from my application makes it act as I want it to. Does anyone have any light to shine on the subject? I don't think it's a locking issue as even if I do the second set of steps quicker than the first, still no error. It's a Seam application using Hibernate 3.3.2.GA & 3.4.0.GA.

    Read the article

  • Generating different randoms valid for a day on different independent devices?

    - by Pentium10
    Let me describe the system. There are several mobile devices, each independent from each other, and they are generating content for the same record id. I want to avoid generating the same content for the same record on different devices, for this I though I would use a random and make it so too cluster the content pool based on these randoms. Suppose you have choices from 1 to 100. Day 1 Device#1 will choose for the record#33 between 1-10 Device#2 will choose for the record#33 between 40-50 Device#3 will choose for the record#33 between 50-60 Device#1 will choose for the record#55 between 40-50 Device#2 will choose for the record#55 between 1-10 Device#3 will choose for the record#55 between 10-20 Device#1 will choose for the record#11 between 1-10 Device#2 will choose for the record#22 between 1-10 Device#3 will choose for the record#99 between 1-10 Day 2 Device#1 will choose for the record#33 between 90-100 Device#2 will choose for the record#33 between 1-10 Device#3 will choose for the record#33 between 50-60 They don't have access to a central server. Data available for each of them: IMEI (unique per mobile) Date of today (same on all devices) Record id (same on all devices) What do you think, how is it possible? ps. tags can be edited

    Read the article

  • Why I cannot see an image if I do not use the full name of an image?

    - by Roman
    I try to add an image to JPanel. It works if I specify the full name of the image (including name of all folders). But I want my software to be machine independent (another machine does not have the same folder structure as my machine has). So, I put my image to the same place where the source is and in my code I use just name of the image (no folders' names). It does not work. I put my image into the folder where my executables are. It does not work again. So, why it does not work and what can I do with that?

    Read the article

  • Oval collision detection not working properly

    - by William
    So I'm trying to implement a test where a oval can connect with a circle, but it's not working. edist = (float) Math.sqrt(Math.pow((px + ((pwidth/2) )) - (bx + (bsize/2)), 2) + Math.pow(-((py + ((pwidth/2)) ) - (bx + (bsize/2))), 2)); and here is the full code (requires Slick2D): import org.newdawn.slick.AppGameContainer; import org.newdawn.slick.BasicGame; import org.newdawn.slick.Color; import org.newdawn.slick.GameContainer; import org.newdawn.slick.Graphics; import org.newdawn.slick.Input; import org.newdawn.slick.SlickException; public class ColTest extends BasicGame{ float px = 50; float py = 50; float pheight = 50; float pwidth = 50; float bx = 200; float by = 200; float bsize = 200; float edist; float pspeed = 3; Input input; public ColTest() { super("ColTest"); } @Override public void init(GameContainer gc) throws SlickException { } @Override public void update(GameContainer gc, int delta) throws SlickException { input = gc.getInput(); try{ if(input.isKeyDown(Input.KEY_UP)) py-=pspeed; if(input.isKeyDown(Input.KEY_DOWN)) py+=pspeed; if(input.isKeyDown(Input.KEY_LEFT)) px-=pspeed; if(input.isKeyDown(Input.KEY_RIGHT)) px+=pspeed; } catch(Exception e){} } public void render(GameContainer gc, Graphics g) throws SlickException { g.setColor(new Color(255,255,255)); g.drawString("col: " + col(), 10, 10); g.drawString("edist: " + edist + " dist: " + dist, 10, 100); g.fillRect(px, py, pwidth, pheight); g.setColor(new Color(255,0,255)); g.fillOval(px, py, pwidth, pheight); g.setColor(new Color(255,255,255)); g.fillOval(200, 200, 200, 200); } public boolean col(){ edist = (float) Math.sqrt(Math.pow((px + ((pwidth/2) )) - (bx + (bsize/2)), 2) + Math.pow(-((py + ((pwidth/2)) ) - (bx + (bsize/2))), 2)); if(edist <= (bsize/2) + (px + (pwidth/2))) return true; else return false; } public float rotate(float x, float y, float ox, float oy, float a, boolean b) { float dst = (float) Math.sqrt(Math.pow(x-ox,2.0)+ Math.pow(y-oy,2.0)); float oa = (float) Math.atan2(y-oy,x-ox); if(b) return (float) Math.cos(oa + Math.toRadians(a))*dst+ox; else return (float) Math.sin(oa + Math.toRadians(a))*dst+oy; } public static void main(String[] args) throws SlickException { AppGameContainer app = new AppGameContainer( new ColTest() ); app.setShowFPS(false); app.setAlwaysRender(true); app.setTargetFrameRate(60); app.setDisplayMode(800, 600, false); app.start(); } }

    Read the article

  • playing two streams on android

    - by Yanush
    Hello, I'm looking for a way (or at least to be pointed in the right direction) to play two streams of audio on android simultaneously but each on a different channel (e.g one in the speaker and one through the headphones) I'm not even sure its possible hardware wise. Any thoughts, clues ? Y

    Read the article

< Previous Page | 871 872 873 874 875 876 877 878 879 880 881 882  | Next Page >