Search Results

Search found 33433 results on 1338 pages for 'java annotations'.

Page 848/1338 | < Previous Page | 844 845 846 847 848 849 850 851 852 853 854 855  | Next Page >

  • Is unnecessary error handling recommended in business logic? eg. Null check/Percentage limit check etc

    - by novice_at_work
    We usually put unnecessary checks in our business logic to avoid failures. Eg. 1. public ObjectABC funcABC(){ ObjectABC obj = new ObjectABC; .......... .......... //its never set to null here. .......... return obj; } ObjectABC o = funABC(); if(o!=null){ //do something } Why do we need this null check if we are sure that it will never be null? Is it a good practice or not? 2. int pplReached = funA(..,..,..); int totalPpl = funB(..,..,..); funA() just puts a few more restriction over result of funB(). Double percentage = (totalPpl==0||totalPpl<pplReached) ? 0.0 : pplReached/totalPpl; Do we again need this check? The questions is: Aren't we swallowing some fundamental issue by putting such checks? Issues which should be shown ideally, are avoided by putting these checks. What is the recommended way?

    Read the article

  • for loop will not loop

    - by Bjørn Jostein Aurheim
    I have a for loop that I will use to compute time intervals to add to an ArrayList. The problem is that I can not prove that the for loop is being executed. Nothing is printed when using the system.out.println() statement, and nothing is added to the array from inside the loop ... any sugestions? // lager tidspunkter og legger disse inn i en Array kalt tider tid.setTimer(16); tid.setMinutter(0); tid.setSekunder(0); tider.add(tid.asString());// String "16:00" is added as it should System.out.println("tiden er: "+tid.asString());// gives 16:00 printed for(int i=0;i>12;i++){ System.out.println("er i løkken");// gives nothing printed tid.increaseMinutter(30); System.out.println(tid.asString());// gives nothing printed tider.add(tid.asString()); }

    Read the article

  • Swing Timer in Conjunction with Possible Long-running Background Task

    - by javacavaj
    I need to perform a task repeatedly that affects both GUI-related and non GUI-related objects. One caveat is that no action should performed if the previous task had not completed when the next timer event is fired. My initial thoughts are to use a SwingTimer in conjunction with a javax.swing.SwingWorker object. The general setup would look like this. class { timer = new Timer(speed, this); timer.start(); public void actionPerformed(ActionEvent e) { SwingWorker worker = new SwingWorker() { @Override public ImageIcon[] doInBackground() { // potential long running task } @Override public void done() { // update GUI on event dispatch thread when complete } } } Some potential issues I see with this approach are: 1) Multiple SwingWorkers will be active if a worker has not completed before the next ActionEvent is fired by the timer. 2) A SwingWorker is only designed to be executed once, so holding a reference to the worker and reusing (is not?) a viable option. Is there a better way to achieve this?

    Read the article

  • hibernate search

    - by Odelya
    Hi! I am using Hibernate. I am looking for a free text engine. Before I investigate into it I need your experience. I have in my applications user, role and object table. Where a user is connected to one or more roles, and a role is connected to one or more objects. In my free text search, the user can reach only data that he is allowed to watch by object table. Can Hibernate search help me with it?

    Read the article

  • Is it bad practice to change state inside of an if statement?

    - by Benjamin
    I wrote some code that looks similar to the following: String SKIP_FIRST = "foo"; String SKIP_SECOND = "foo/bar"; int skipFooBarIndex(String[] list){ int index; if (list.length >= (index = 1) && list[0].equals(SKIP_FIRST) || list.length >= (index = 2) && (list[0] + "/" + list[1]).equals(SKIP_SECOND)){ return index; } return 0; } String[] myArray = "foo/bar/apples/peaches/cherries".split("/"); print(skipFooBarIndex(myArray); This changes state inside of the if statement by assigning index. However, my coworkers disliked this very much. Is this a harmful practice? Is there any reason to do it?

    Read the article

  • Avoid Spring ApllicationContext instanciation

    - by Ceddoc
    I use Spring 3 to make a simple configuration. I have an XML file called PropertyBeans.xml like that : <bean id="propertyBean" class="com.myapp.PropertyBean"> <property name="rootDirLogPath" value="C:\Users\dede" /> </bean> I have the bean which match this XML and then I want to use this bean with the value injected. Actually I have : ApplicationContext context = new ClassPathXmlApplicationContext("AppPropertyBeans.xml"); PropertyBean obj = (PropertyBean) context.getBean("propertyBean"); String rootDirLogPath = obj.getRootDirLogPath(); This works great but I want to know if there's a way to avoid the instantiation of ApplicationContext at each time I want to use a bean. I've heard about BeanFactory is that a good idea? Which are the others solutions? In other words: Am I supposed to called this Application context instanciation in every Controller in spring MVC?

    Read the article

  • Comparing two Objects which implement the same interface for equality / equivalence - Design help

    - by gav
    Hi All, I have an interface and two objects implementing that interface, massively simplied; public interface MyInterface { public int getId(); public int getName(); ... } public class A implements MyInterface { ... } public class B implements MyInterface { ... } We are migrating from using one implementation to the other but I need to check that the objects of type B that are generated are equivalent to those of type A. Specifically I mean that for all of the interface methods an object of Type A and Type B will return the same value (I'm just checking my code for generating this objects is correct). How would you go about this? Map<String, MyInterface> oldGeneratedObjects = getOldGeneratedObjects(); Map<String, MyInterface> newGeneratedObjects = getNewGeneratedObjects(); // TODO: Establish that for each Key the Values in the two maps return equivalent values. I'm looking for good coding practices and style here. I appreciate that I could just iterate through one key set pulling out both objects which should be equivalent and then just call all the methods and compare, I'm just thinking there may be a cleaner, more extensible way and I'm interested to learn what options there might be. Would it be appropriate / possible / advised to override equals or implement Comparable? Thanks in advance, Gavin

    Read the article

  • How to retrieve the ordered list of best articles having a minimum number of votes by using HSQL ?

    - by fabien7474
    I have a Vote domain class from my grails application containing properties like article_id and note I want to HQL query the Vote domain class in order to retrieve the 5 best rated articles having at least 10 votes. I tried : SELECT v.article_id, avg(v.note), count(*) FROM vote v where count(*) >= 10 group by v.article_id order by avg(v.note) desc limit 5; But unfortunately the insertion of where count(*) >= 10 throws an error. How can I do that in a simple way? Thank you for your help.

    Read the article

  • What is Chain Matrix Multiplication ?

    - by Hellnar
    Hello, I am trying to understand what is a chain matrix multiplication and how it is different from a regular multiplication. I have checked several sourcers yet all seem to be very academically explained for me to understand. I guess it is a form of dynamic programming algorithm to achieve the operation in an optimised way but I didn't go any further. Thanks

    Read the article

  • removing horizontal scrollbar for textarea

    - by charan
    Hi. im working on javaswings. i had a textarea in a panel. i dont need horizontal scrollbar for that textArea. only vertical scrollbar is needed. i disabled auto scrollbar options, but still the horizantal scrollbar is working. please help me in thz..

    Read the article

  • Sorted sets and comparators

    - by Jack
    Hello, I'm working with a TreeSetthat is meant to store pathfind locations used during the execution of a A* algorithm. Basically until there are "open" elements (still to be exhaustively visited) the neighbours of every open element are taken into consideration and added to a SortedSetthat keeps them ordered by their cost and heuristic cost. This means that I have a class like: public class PathTileInfo implements Comparable<PathTileInfo> { int cost; int hCost; final int x, y; @Override public int compareTo(PathTileInfo t2) { int c = cost + hCost; int c2 = t2.cost + t2.hCost; int costComp = c < c2 ? -1 : (c > c2 ? 1: 0); return costComp != 0 ? costComp : (x < t2.x || y < t2.y ? -1 : (x > t2.x || y > t2.y ? 1 : 0)); } @Override public boolean equals(Object o2) { if (o2 instanceof PathTileInfo) { PathTileInfo i = (PathTileInfo)o2; return i.cost + i.hCost == cost + hCost && x == i.x && y == i.y; } return false; } } In this way first the total cost is considered, then, since a total ordering is needed (consistency with equals) a ordering according to the x,y coordinate is taken into account. This should work but simply it doesn't, if I iterate over the TreeSet during the algorithm execution like in for (PathTileInfo t : openSet) System.out.print("("+t.x+","+t.y+","+(t.cost+t.hCost)+") "); I get results in which the right ordering is not kept, eg: (7,7,6) (7,6,7) (6,8,6) (6,6,7) (5,8,7) (5,7,7) (6,7,6) (6,6,7) (6,5,7) (5,7,7) (5,5,8) (4,7,7) (4,6,8) (4,5,8) is there something subtle I am missing? Thanks!

    Read the article

  • How to build jars from IntelliJ properly?

    - by ripper234
    I have a project that contains a single module, and some dependencies. I'd like to create a jar, in a separate directory, that contains the compiled module. In addition, I'd like to have the dependencies present beside my module. No matter how I twist IntelliJ's "build jar" process, the output of my module appears empty (besides a META-INF file).

    Read the article

  • Hibernate - get the size of a list in a property

    - by mada
    I have a class A which have a list of B elements. In my A class i would like to add: int size; which will be valued with the number of B elements. So when I would call myA.getSize() I will have it. Is it possible to map a count query with a single property in the hibernate mapping? I don't want to load the list that is why i would like to add a size property.

    Read the article

  • Weird stuttering issues not related to GC.

    - by Smills
    I am getting some odd stuttering issues with my game even though my FPS never seems to drop below 30. About every 5 seconds my game stutters. I was originally getting stuttering every 1-2 seconds due to my garbage collection issues, but I have sorted those and will often go 15-20 seconds without a garbage collection. Despite this, my game still stutters periodically even when there is no GC listed in logcat anywhere near the stutter. Even when I take out most of my code and simply make my "physics" code the below code I get this weird slowdown issue. I feel that I am missing something or overlooking something. Shouldn't that "elapsed" code that I put in stop any variance in the speed of the main character related to changes in FPS? Any input/theories would be awesome. Physics: private void updatePhysics() { //get current time long now = System.currentTimeMillis(); //added this to see if I could speed it up, it made no difference Thread myThread = Thread.currentThread(); myThread.setPriority(Thread.MAX_PRIORITY); //work out elapsed time since last frame in seconds double elapsed = (now - mLastTime2) / 1000.0; mLastTime2 = now; //measures FPS and displays in logcat once every 30 frames fps+=1/elapsed; fpscount+=1; if (fpscount==30) { fps=fps/fpscount; Log.i("myActivity","FPS: "+fps+" Touch: "+touch); fpscount=0; } //this should make the main character (theoretically) move upwards at a steady pace mY-=100*elapsed; //increase amount I translate the draw to = main characters Y //location if the main character goes upwards if (mY<=viewY) { viewY=mY; } }

    Read the article

  • Exception durin processing XSLT transformation!

    - by Artic
    I'm usin such code to generate contents file. try { StreamResult result = new StreamResult(); TransformerFactory tf = TransformerFactory.newInstance(); for (String item: groups){ item = item.replaceAll(" ", "-").toLowerCase(); result.setOutputStream(new FileOutputStream(path+item+".html")); Templates templ = tf.newTemplates(xsltSource); Transformer transf = templ.newTransformer(); transf.clearParameters(); transf.setParameter("group", item); transf.transform(xmlSource, result); } } catch (TransformerConfigurationException e) { throw new SinkException(e.getMessage()); } catch (TransformerException e) { throw new SinkException(e.getMessage()); } But on second iteration I have an exception ERROR: javax.xml.transform.TransformerException: com.sun.org.apache.xml.internal.utils.WrappedRuntimeException: Read error Cann't understand what is the reason?

    Read the article

  • Interpret a rule applying multiple xpath queries on multiple XML documents

    - by Damien
    Hi, I need to build a component which would take a few XML documents in input and check the following kind of rules: XML1:/bookstore/book[price>35.00] != null and (XML2:/city/name = 'Montreal' or XML3://customer[@language] contains 'en') Basically my component should be able to: substitute the XML tokens with the corresponding XML document(before colon) apply xpath query on this XML document check the xpath output against expected result ("=", "!=", "contains") follow the basic syntax ("and", "or" and parentheses) tell if the rule is true or false Do you know any library which could help me? maybe JavaCC? Thanks

    Read the article

  • ResultSet and aggregation

    - by kachanov
    Ok, I admit my situation is special There is a data system that supports SQL-92 and JDBC interface However the SQL requets are pretty expensive, and in my application I need to retreive the same data multiple times and aggregate it ("group by") on different fields to show different dimensions of the same data. For example on one screen I have three tables that show the same set or records but aggregated by City (1st grid), by Population (2nd grid), by number of babies (3rd grid) This amounts to 3 SQL queries (which is very slow), UNLESS anyone of you can suggest any idea any library from apache commons or from google code, so that I can select all records into ResultSet and get 3 arrays of data group by different fields from this single ResultSet. Am I'm missing some obvious and unexpected solution to this problem?

    Read the article

  • Use ObjectOutputStream and FileOutputStream with FileWriter

    - by wishi
    Hi! Is there any way to use ObjectOutputStream like this: <tag>output of the ObjectOutputStream</tag> If I try: FileOutputStream fos = new FileOutputStream(filename); ObjectOutputStream oos = new ObjectOutputStream(fos); FileWriter fw = new FileWriter(fos); And for example: fw.write("<tag>"); oos.write(cool_object); fw.wrote("</tag>"); I don't get that result. It seems the ObjectOutputStream overwrites the file completly each and every time.

    Read the article

  • Displaying an Image in an activity using URI

    - by evkwan
    Hi, I'm writing an application that uses Intent(MediaStore.ACTION_IMAGE_CAPTURE) to capture and image. On the process of capturing the image, I noted the output of the image's URI. Right after finishing the camera activity, I wish to display the image using this specific URI. The method I used to capture images is: private void saveFullImage() { Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); File file = new File(Environment.getExternalStorageDirectory(), "test.jpg"); outputFileUri = Uri.fromFile(file); intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri); startActivityForResult(intent, TAKE_PICTURE); } Which is a method taken from Reto Meier's book Professional Android 2 Application Development. The method works fine, and I assume that the URI of the picture I just took is stored in the outputFileUri variable. Then at this point of the code is where I want to display the picture: @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == TAKE_PICTURE) { //I want to display the picture I just took here //using the URI } } I'm not sure how to do it. I tried creating a new layout object and a new ImageView object using the method setImageURI(outputFileUri). My main layout (xml) did not have a ImageView object. But even when I set the contentView to the new layout with the ImageView attached to it, it doesn't display anything. I tried creating a Bitmap object from the URI and set it to the ImageView, but I get an unexpected error and forced exit. I have seen examples from here here which creates a Bitmap from URI, but it's not displaying it? My question is just how to display an image in the middle of a running activity? Do I need to get the File Path (like this) in order to display it? If I make a Bitmap out of the URI, how do I display the Bitmap? I'm just probably missing something simple...so any help would be a greatly appreciated! Also additional question for thought: If I were to take multiple pictures, would you recommend me to use the SimpleCursorAdapter instead? Thanks!

    Read the article

< Previous Page | 844 845 846 847 848 849 850 851 852 853 854 855  | Next Page >