Search Results

Search found 25521 results on 1021 pages for 'static objects'.

Page 305/1021 | < Previous Page | 301 302 303 304 305 306 307 308 309 310 311 312  | Next Page >

  • In Java it seems Public constructors are always a bad coding practice

    - by Adam Gent
    This maybe a controversial question and may not be suited for this forum (so I will not be insulted if you choose to close this question). It seems given the current capabilities of Java there is no reason to make constructors public ... ever. Friendly, private, protected are OK but public no. It seems that its almost always a better idea to provide a public static method for creating objects. Every Java Bean serialization technology (JAXB, Jackson, Spring etc...) can call a protected or private no-arg constructor. My questions are: I have never seen this practice decreed or written down anywhere? Maybe Bloch mentions it but I don't own is book. Is there a use case other than perhaps not being super DRY that I missed? EDIT: I explain why static methods are better. .1. For one you get better type inference. For example See Guava's http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained .2. As a designer of the class you can later change what is returned with a static method. .3. Dealing with constructor inheritance is painful especially if you have to pre-calculate something.

    Read the article

  • Performance tuning of a Hibernate+Spring+MySQL project operation that stores images uploaded by user

    - by Umar
    Hi I am working on a web project that is Spring+Hibernate+MySQL based. I am stuck at a point where I have to store images uploaded by a user into the database. Although I have written some code that works well for now, but I believe that things will mess up when the project would go live. Here's my domain class that carries the image bytes: @Entity public class Picture implements java.io.Serializable{ long id; byte[] data; ... // getters and setters } And here's my controller that saves the file on submit: public class PictureUploadFormController extends AbstractBaseFormController{ ... protected ModelAndView onSubmit(HttpServletRequest request, HttpServletResponse response, Object command, BindException errors) throws Exception{ MutlipartFile file; // getting MultipartFile from the command object ... // beginning hibernate transaction ... Picture p=new Picture(); p.setData(file.getBytes()); pictureDAO.makePersistent(p); // this method simply calls getSession().saveOrUpdate(p) // committing hiernate transaction ... } ... } Obviously a bad piece of code. Is there anyway I could use InputStream or Blob to save the data, instead of first loading all the bytes from the user into the memory and then pushing them into the database? I did some research on hibernate's support for Blob, and found this in Hibernate In Action book: java.sql.Blob and java.sql.Clob are the most efficient way to handle large objects in Java. Unfortunately, an instance of Blob or Clob is only useable until the JDBC transaction completes. So if your persistent class defines a property of java.sql.Clob or java.sql.Blob (not a good idea anyway), you’ll be restricted in how instances of the class may be used. In particular, you won’t be able to use instances of that class as detached objects. Furthermore, many JDBC drivers don’t feature working support for java.sql.Blob and java.sql.Clob. Therefore, it makes more sense to map large objects using the binary or text mapping type, assuming retrieval of the entire large object into memory isn’t a performance killer. Note you can find up-to-date design patterns and tips for large object usage on the Hibernate website, with tricks for particular platforms. Now apparently the Blob cannot be used, as it is not a good idea anyway, what else could be used to improve the performance? I couldn't find any up-to-date design pattern or any useful information on Hibernate website. So any help/recommendations from stackoverflowers will be much appreciated. Thanks

    Read the article

  • MovieViewControl unable to become a receiver during Broadcast

    - by Paulina D
    Hi! I'm currently trying to catch a broadcast message with the MovieViewControl class, already added the filter in the Manifest //In MovieViewControl private static final String SERVICECMD = "com.android.music.musicservicecommand"; private static final String CMDNAME = "command"; private static final String CMDPAUSE = "pause"; @Override public void onReceive(Context context, Intent intent) { String intentAction = intent.getAction(); if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intentAction)) { Intent i = new Intent(intent.ACTION_MAIN); i.setAction(SERVICECMD); i.putExtra(CMDNAME, CMDPAUSE); mVideoView.pause(); context.startActivity(i); } } but when I do my trial, I get this (very) huge exception: W/dalvikvm( 1630): threadid=3: thread exiting with uncaught exception (group=0x4001b1b8) E/AndroidRuntime( 1630): Uncaught handler: thread main exiting due to uncaught exception E/AndroidRuntime( 1630): java.lang.RuntimeException: Unable to instantiate receiver com.android.gallery.MovieViewControl: java.lang.ClassNotFoundException: com.android.gallery.MovieViewControl in loader dalvik.system.PathClassLoader@438ff048 E/AndroidRuntime( 1630): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2616) E/AndroidRuntime( 1630): at android.app.ActivityThread.access$3100(ActivityThread.java:119) E/AndroidRuntime( 1630): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1913) E/AndroidRuntime( 1630): at android.os.Handler.dispatchMessage(Handler.java:99) E/AndroidRuntime( 1630): at android.os.Looper.loop(Looper.java:123) E/AndroidRuntime( 1630): at android.app.ActivityThread.main(ActivityThread.java:4363) E/AndroidRuntime( 1630): at java.lang.reflect.Method.invokeNative(Native Method) E/AndroidRuntime( 1630): at java.lang.reflect.Method.invoke(Method.java:521) E/AndroidRuntime( 1630): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) E/AndroidRuntime( 1630): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) E/AndroidRuntime( 1630): at dalvik.system.NativeStart.main(Native Method) E/AndroidRuntime( 1630): Caused by: java.lang.ClassNotFoundException: com.android.gallery.MovieViewControl in loader dalvik.system.PathClassLoader@438ff048 E/AndroidRuntime( 1630): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243) E/AndroidRuntime( 1630): at java.lang.ClassLoader.loadClass(ClassLoader.java:573) E/AndroidRuntime( 1630): at java.lang.ClassLoader.loadClass(ClassLoader.java:532) E/AndroidRuntime( 1630): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2609) E/AndroidRuntime( 1630): ... 10 more Any hints on what might I be missing? Thanks in advance!

    Read the article

  • Why this code showing error in W3C validator?

    - by metal-gear-solid
    Why this code showing error in W3C validator "character data is not allowed here" <blockquote>all visible objects, man, are but as pasteboard masks. But in each event -- in the living act, the undoubted deed -- there, some unknown but still reasoning thing puts forth the mouldings of its feature from behind the unreasoning mask. If man will strike, strike through the mask. All visible objects, man, are but as pasteboard masks. But in each event -- in the living act, the undoubted deed -- there, some unknown but still reasoning thing puts forth the mouldings of its feature from behind the unreasoning mask. If man will strike, strike through the mask.</blockquote> It does not giving any error in this validator http://www.onlinewebcheck.com/ and not in https://addons.mozilla.org/en-US/firefox/addon/249/

    Read the article

  • An Efficient data structure for Sorted List

    - by holydiver
    I want to save my objects according to a key in the attributes of my object in a sorted fashion. Later on I'll access these objects sequentially from max key to min key. I'll do some search tasks as well. I consider to use either AVL tree or RB Tree. As far as i know they are nearly equivalent in theory(Both have O(logn)). But in practice which one might be better in performance in my situation. And is there a better alternative than those, considering that I'll mostly do insert and sequentially access to the ds.

    Read the article

  • Reuse implemented business classes in a web applications

    - by Mohammad
    I have implemented my domain layer classes and i have used them in a java application. Now i want to use same classes in a java web application,but i dont know how can i do it? In the java aplication we make and run some objects in main(class and method) and use them while program is running. for example an object that hold a collection of data that will be needed for all user requests. My question is: How can i create and hold such objects and data that should be available for all users and clients.

    Read the article

  • Speeding up templates in GAE-Py by aggregating RPC calls

    - by Sudhir Jonathan
    Here's my problem: class City(Model): name = StringProperty() class Author(Model): name = StringProperty() city = ReferenceProperty(City) class Post(Model): author = ReferenceProperty(Author) content = StringProperty() The code isn't important... its this django template: {% for post in posts %} <div>{{post.content}}</div> <div>by {{post.author.name}} from {{post.author.city.name}}</div> {% endfor %} Now lets say I get the first 100 posts using Post.all().fetch(limit=100), and pass this list to the template - what happens? It makes 200 more datastore gets - 100 to get each author, 100 to get each author's city. This is perfectly understandable, actually, since the post only has a reference to the author, and the author only has a reference to the city. The __get__ accessor on the post.author and author.city objects transparently do a get and pull the data back (See this question). Some ways around this are Use Post.author.get_value_for_datastore(post) to collect the author keys (see the link above), and then do a batch get to get them all - the trouble here is that we need to re-construct a template data object... something which needs extra code and maintenance for each model and handler. Write an accessor, say cached_author, that checks memcache for the author first and returns that - the problem here is that post.cached_author is going to be called 100 times, which could probably mean 100 memcache calls. Hold a static key to object map (and refresh it maybe once in five minutes) if the data doesn't have to be very up to date. The cached_author accessor can then just refer to this map. All these ideas need extra code and maintenance, and they're not very transparent. What if we could do @prefetch def render_template(path, data) template.render(path, data) Turns out we can... hooks and Guido's instrumentation module both prove it. If the @prefetch method wraps a template render by capturing which keys are requested we can (atleast to one level of depth) capture which keys are being requested, return mock objects, and do a batch get on them. This could be repeated for all depth levels, till no new keys are being requested. The final render could intercept the gets and return the objects from a map. This would change a total of 200 gets into 3, transparently and without any extra code. Not to mention greatly cut down the need for memcache and help in situations where memcache can't be used. Trouble is I don't know how to do it (yet). Before I start trying, has anyone else done this? Or does anyone want to help? Or do you see a massive flaw in the plan?

    Read the article

  • How to build boost foreach cycle

    - by Ockonal
    Hi guys! I have some abstract class called IClass (has pure virtual function). There are some classes which inherit IClass: CFirst, CSecond. I want to add objects of classes which inherit into boost::ptr_vector: class IClass { virtual void someFunc() = 0; }; class CFirst : public IClass { }; class CSecond : public IClass { }; boost::ptr_vector<IClass> objectsList; objectsList.push_back(new CFirst()); objectsList.push_back(new CSecond()); And now my goal is to call function (which is declarated in IClass) from all objects in objectsList. I'd prefer to use BOOST_FOREACH: foreach(IClass tempObj, objectsList) { tempObj.someFunc(); } The problem is that IClass - abstract class, so I can't make instance of it for the foreach-cycle. What should I do?

    Read the article

  • Finding the index of a queue that holds a member of a containing object for a given value

    - by Luke Mcneice
    I have a Queue that contains a collection of objects, one of these objects is a class called GlobalMarker that has a member called GlobalIndex. What I want to be able to do is find the index of the queue where the GlobalIndex contains a given value (this will always be unique). Simply using the Contains method shown below returns a bool. How can I obtain the queue index of this match? RealTimeBuffer .OfType<GlobalMarker>() .Select(o => o.GlobalIndex) .Contains(INT_VALUE);

    Read the article

  • Enumerable Contains Enumerable

    - by Tim
    For a method I have the following parameter IEnumerable<string> tags and with to query a list of objects, let's call them Post, that contains a property IEnumerable<string> Tags { get; set; }. My question is: How do I use linq to query for objects that contains all the tags from the tags parameter? private List<Post> posts = new List<Post>(); public IEnumerable<Post> GetPostsWithTags(IEnumerable<string> tags) { return ???; }

    Read the article

  • MVC validation error with strongly typed view

    - by Remnant
    I have a simple form that I would like to validate on form submission. Note I have stripped out the html for ease of viewing <%=Html.TextBox("LastName", "")%> //Lastname entry <%=Html.ValidationMessage("LastName")%> <%=Html.TextBox("FirstName", "")%>//Firstname entry <%=Html.ValidationMessage("FirstName")%> <%=Html.DropDownList("JobRole", Model.JobRoleList)%> //Dropdownlist of job roles <% foreach (var record in Model.Courses) // Checkboxes of different courses for user to select { %> <li><label><input type="checkbox" name="Courses" value="<%=record.CourseName%>" /><%= record.CourseName%></label></li> <% } %> On submission of this form I would like to check that both FirstName and LastName are populated (i.e. non-zero length). In my controller I have: public ActionResult Submit(string FirstName, string LastName) { if (FirstName.Trim().Length == 0) ModelState.AddModelError("FirstName", "You must enter a first name"); if (LastName.Trim().Length == 0) ModelState.AddModelError("LastName", "You must enter a first name"); if (ModelState.IsValid) { //Update database + redirect to action } return View(); //If ModelState not valid, return to View and show error messages } Unfortunately, this code logic produces an error that states that no objects are found for JobRole and Courses. If I remove the dropdownlist and checkboxes then all works fine. The issue appears to be that when I return the View the view is expecting objects for the dropwdownlist and checkboxes (which is sensible as that is what is in my View code) How can I overcome this problem? Things I have considered: In my controller I could create a JobRoleList object and Course object to pass to the View so that it has the objects to render. The issue with this is that it will overwrite any dropdownlist / checkbox selections that the user has already made. In the parameters of my controller method Submit I could aslo capture the JobRoleList object and Course object to pass back to the View. Again, not sure this would capture any items the user has already selected. I have done much googling and reading but I cannot find a good answer. When I look at examples in books or online (e.g. Nerddinner) all the validation examples involve simple forms with TextBox inputs and don't seems to show instances with multiple checkboxes and dropdownlists. Have I missed something obvious here? What would be best practice in this situation? Thanks

    Read the article

  • Why aren't my coordinates matching my JFrame size?

    - by AsLanFromNarnia
    I want to do some drawing in a JPanel but the enclosing JFrame size doesn't seem to match where I've asked the coordinates to be drawn. In my example code, the JFrame size is set to (700, 700) and the last point is drawn at (600, 600). I would expect this point to be drawn 100 pixels away from the right and bottom edges but it isn't (please see screenshot). Here's the code I'm using: import java.awt.Graphics; import javax.swing.JFrame; import javax.swing.JPanel; public class Scratch extends JPanel { static int frameWidth = 700; static int frameHeight = 700; public static void main(String[] args) { JFrame frame = new JFrame(); frame.setSize(frameWidth, frameHeight); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Scratch scratch = new Scratch(); frame.getContentPane().add(scratch); frame.setVisible(true); } @Override public void paintComponent(Graphics g) { g.drawRect(100, 100, 1, 1); g.drawString("100", 100, 100); g.drawRect(200, 200, 1, 1); g.drawString("200", 200, 200); g.drawRect(300, 300, 1, 1); g.drawString("300", 300, 300); g.drawRect(400, 400, 1, 1); g.drawString("400", 400, 400); g.drawRect(500, 500, 1, 1); g.drawString("500", 500, 500); g.drawRect(600, 600, 1, 1); g.drawString("600", 600, 600); } }

    Read the article

  • to connect matlab with java

    - by user304005
    Through the below given code I was able to connect to matlab. But I was not able to execute the script file containing matlab code...Please help me to modify the code so as to execute the matlab code.... Here luck2 is a .m file.... import java.io.InputStreamReader; import java.io.*; public class matlab { private static File myMATLABScript; public static String runScript(File luck2) { String output = "" ; String error = ""; try { String commandToRun ="C:\\Program Files\\MATLAB\\R2009a\\bin\\matlab -nodisplay <" + "Z:\\sem\\java\\luck2"; //String commandToRun = "matlab -nosplash -r myMATLABScript -nodisplay -nodesktop < " + opentxt; System.out.println(commandToRun); Process p = Runtime.getRuntime().exec(commandToRun); String s; BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream())); BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream())); System.out.println("\nHere is the standard output of the command:\n"); while ((s = stdInput.readLine()) != null) { System.out.println("haiiiiiiiiiiii"); output = s + "\n"; System.out.println(s); } while ((s = stdError.readLine()) != null) { error = s + "\n"; System.out.println(s); } } catch (Exception e) { System.out.println("exception happened here what I know:"); e.printStackTrace(); System.exit(-1); } return output + error; } public static void main(String[] args) throws IOException { matlab m = new matlab(); matlab.runScript(myMATLABScript); //matlab.runScript(); } }

    Read the article

  • Using Doctrine to abstract CRUD operations

    - by TomWilsonFL
    This has bothered me for quite a while, but now it is necessity that I find the answer. We are working on quite a large project using CodeIgniter plus Doctrine. Our application has a front end and also an admin area for the company to check/change/delete data. When we designed the front end, we simply consumed most of the Doctrine code right in the controller: //In semi-pseudocode function register() { $data = get_post_data(); if (count($data) && isValid($data)) { $U = new User(); $U->fromArray($data); $U->save(); $C = new Customer(); $C->fromArray($data); $C->user_id = $U->id; $C->save(); redirect_to_next_step(); } } Obviously when we went to do the admin views code duplication began and considering we were in a "get it DONE" mode so it now stinks with code bloat. I have moved a lot of functionality (business logic) into the model using model methods, but the basic CRUD does not fit there. I was going to attempt to place the CRUD into static methods, i.e. Customer::save($array) [would perform both insert and update depending on if prikey is present in array], Customer::delete($id), Customer::getObj($id = false) [if false, get all data]. This is going to become painful though for 32 model objects (and growing). Also, at times models need to interact (as the interaction above between user data and customer data), which can't be done in a static method without breaking encapsulation. I envision adding another layer to this (exposing web services), so knowing there are going to be 3 "controllers" at some point I need to encapsulate this CRUD somewhere (obviously), but are static methods the way to go, or is there another road? Your input is much appreciated.

    Read the article

  • Why is django admin not accepting Nullable foreign keys?

    - by p.g.l.hall
    Here is a simplified version of one of my models: class ImportRule(models.Model): feed = models.ForeignKey(Feed) name = models.CharField(max_length=255) feed_provider_category = models.ForeignKey(FeedProviderCategory, null=True) target_subcategories = models.ManyToManyField(Subcategory) This class manages a rule for importing a list of items from a feed into the database. The admin system won't let me add an ImportRule without selecting a feed_provider_category despite it being declared in the model as nullable. The database (SQLite at the moment) even checks out ok: >>> .schema ... CREATE TABLE "someapp_importrule" ( "id" integer NOT NULL PRIMARY KEY, "feed_id" integer NOT NULL REFERENCES "someapp_feed" ("id"), "name" varchar(255) NOT NULL, "feed_provider_category_id" integer REFERENCES "someapp_feedprovidercategory" ("id"), ); ... I can create the object in the python shell easily enough: f = Feed.objects.get(pk=1) i = ImportRule(name='test', feed=f) i.save() ...but the admin system won't let me edit it, of course. How can I get the admin to let me edit/create objects without specifying that foreign key?

    Read the article

  • Advice on Method overloads.

    - by Muhammad Kashif Nadeem
    Please see following methods. public static ProductsCollection GetDummyData(int? customerId, int? supplierId) { try { if (customerId != null && customerId > 0) { Filter.Add(Customres.CustomerId == customerId); } if (supplierId != null && supplierId > 0) { Filter.Add(Suppliers.SupplierId == supplierId); } ProductsCollection products = new ProductsCollection(); products.FetchData(Filter); return products; } catch { throw; } } public static ProductsCollection GetDummyData(int? customerId) { return ProductsCollection GetDummyData(customerId, (int?)null); } public static ProductsCollection GetDummyData() { return ProductsCollection GetDummyData((int?)null); } 1- Please advice how can I make overloads for both CustomerId and SupplierId because only one overload can be created with GetDummyData(int? ). Should I add another argument to mention that first argument is CustomerId or SupplierId for example GetDummyData(int?, string). OR should I use enum as 2nd argument and mention that first argument is CustoemId or SupplierId. 2- Is this condition is correct or just checking 0 is sufficient - if (customerId != null && customerId 0) 3- Using Try/catch like this is correct? 4- Passing (int?)null is correct or any other better approach. Edit: I have found some other posts like this and because I have no knowledge of Generics that is why I am facing this problem. Am I right? Following is the post. http://stackoverflow.com/questions/422625/overloaded-method-calling-overloaded-method

    Read the article

  • Scheme: what are the benefits of letrec?

    - by Ixmatus
    While reading "The Seasoned Schemer" I've begun to learn about letrec. I understand what it does (can be duplicated with a Y-Combinator) but the book is using it in lieu of recurring on the already defined function operating on arguments that remain static. An example of an old function using the defined function recurring on itself (nothing special): (define (substitute new old lat) (cond ((null? l) '()) ((eq? (car l) old) (cons new (substitute new old (cdr l)))) (else (cons (car l) (substitute new old (cdr l)))))) Now for an example of that same function but using letrec: (define (substitute new old lat) (letrec ((replace (lambda (l) (cond ((null? l) '()) ((eq? (car l) old) (cons new (replace (cdr l)))) (else (cons (car l) (replace (cdr l)))))))) (replace lat))) Aside from being slightly longer and more difficult to read I don't know why they are rewriting functions in the book to use letrec. Is there a speed enhancement when recurring over a static variable this way because you don't keep passing it?? Is this standard practice for functions with arguments that remain static but one argument that is reduced (such as recurring down the elements of a list)? Some input from more experienced Schemers/LISPers would help!

    Read the article

  • How much does Website Development cost nowadays?

    - by Andreas Grech
    I am thinking of setting up my own freelance business but coming from a workplace that offers a particular service to huge clients, I do not know what are the current charges for websites are nowadays. I know that as technology just keeps changing and changing (most of the time, for the better...), the amount you charge for a single website is constantly differing. Like for example, I don't think static websites (with just static html pages) are that expensive today, no? (as i said, I might be mistaken since I haven't really touched on this freelance industry yet) So, freelance web-developers out there, can you give me estimates on how much you charge for your clients? Some examples of websites that I want to know an approx charge: ~10 static html pages ~10 dhtml pages (with maybe a flasy menu on the top/side) Database driven websites with a standard CMS (be it the one you developed, or an existing one) Database driven but with a custom-built cms for the particular client Using an existing template for a design Starting the design from scratch etc... I know that the normally clients don't really care about the technologies used to construct their websites, but do you charge differently according to which technology you use to build the website with?; as in, is the technology a factor when setting the price? ...being ASP.Net, PHP, Ruby On Rails etc... Also, how do you go on about charging your clients for your services? What are the major factors that you consider when setting a price tag for a website to a client ? And better yet, how do you even find prospective clients? <= [or should I leave this question for a different post?] Btw, in your post, also mention some numbers (in cash values, be it in USD, GBP, EUR or anything) because I want to be able to take calculate some averages from this post when some answers stack up

    Read the article

  • Factory Method pattern and public constructor

    - by H4mm3rHead
    Hi, Im making a factory method that returns new instances of my objects. I would like to prevent anyone using my code from using a public constructor on my objects. Is there any way of doing this? How is this typically accomplished: public abstract class CarFactory { public abstract ICar CreateSUV(); } public class MercedesFactory : CarFactory { public override ICar CreateSUV() { return new Mercedes4WD(); } } I then would like to limit/prevent the other developers (including me in a few months) from making an instance of Mercedes4WD. But make them call my factory method. How to?

    Read the article

  • How do you deal with the conflict between ActiveSupport::JSON and the JSON gem?

    - by Luke Francl
    I am stumped with this problem. ActiveSupport::JSON defines to_json on various core objects and so does the JSON gem. However, the implementation is not the same -- the ActiveSupport version takes arguments and the JSON gem version doesn't. I installed a gem that required the JSON gem and my app broke. The issue is that I'm using to_json in a controller that returns a list of objects, but I want to control which attributes are returned. When code anywhere in my system does require 'json' I get this error message: TypeError: wrong argument type Hash (expected Data) I tried a couple of things that I read online to fix it, but nothing worked. I ended up re-writing the gem to use ActiveSupport::JSON.decode instead of JSON.parse. This works but it's not sustainable...I can't be forking gems every time I want to use a gem that requires the JSON gem. Update: The best solution of this problem is to upgrade to Rails 2.3 or higher, which fixed it.

    Read the article

  • How to access controller dynamic properties within a base controller's constructor in Grails?

    - by 4h34d
    Basically, I want to be able to assign objects created within filters to members in a base controller from which every controller extends. Any possible way to do that? Here's how I tried, but haven't got to make it work. What I'm trying to achieve is to have all my controllers extend a base controller. The base controller's constructor would be used to assign values to its members, those values being pulled from the session map. Example below. File grails-app/controllers/HomeController.groovy: class HomeController extends BaseController { def index = { render username } } File grails-app/controllers/BaseController.groovy: abstract class BaseController { public String username public BaseController() { username = session.username } } When running the app, the output shown is: 2010-06-15 18:17:16,671 [main] ERROR [localhost].[/webapp] - Exception sending context initialized event to listener instance of class org.codehaus.groovy.grails.web.context.GrailsContextLoaderListener org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pluginManager' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.RuntimeException: Unable to locate constructor with Class parameter for class org.codehaus.groovy.grails.commons.DefaultGrailsControllerClass ... Caused by: java.lang.RuntimeException: Unable to locate constructor with Class parameter for class org.codehaus.groovy.grails.commons.DefaultGrailsControllerClass ... Caused by: java.lang.reflect.InvocationTargetException ... Caused by: org.codehaus.groovy.grails.exceptions.NewInstanceCreationException: Could not create a new instance of class [com.my.package.controller.HomeController]! ... Caused by: groovy.lang.MissingPropertyException: No such property: session for class: com.my.package.controller.HomeController at com.my.package.controller.BaseController.<init>(BaseController.groovy:16) at com.my.package.controller.HomeController.<init>(HomeController.groovy) ... 2010-06-15 18:17:16,687 [main] ERROR core.StandardContext - Error listenerStart 2010-06-15 18:17:16,687 [main] ERROR core.StandardContext - Context [/webapp] startup failed due to previous errors And the app won't run. This is just an example as in my case I wouldn't want to assign a username to a string value, but rather a few objects pulled from the session map. The objects pulled from the session map are being set within filters. The alternative I see is being able to access the controller's instance within the filter's execution. Is that possible? Please help! Thanks a bunch!

    Read the article

  • Why StrinUtils Apache class is not recognized in android?

    - by Maxood
    Why import org.apache.commons.lang.StringUtils cannot be imported in android by default. Do i have to include an external library? Then where can i find that library on the web? package com.myapps.urlencoding; import android.app.Activity; import org.apache.commons.lang.StringUtils; public class EncodeIdUtil extends Activity { /** Called when the activity is first created. */ private static Long multiplier=Long.parseLong("1zzzz",36); /** * Encodes the id. * @param id the id to encode * @return encoded string */ public static String encode(Long id) { return StringUtils.reverse(Long.toString((id*multiplier), 35)); } /** * Decodes the encoded id. * @param encodedId the encodedId to decode * @return the Id * @throws IllegalArgumentException if encodedId is not a validly encoded id. */ public static Long decode(String encodedId) throws IllegalArgumentException { long product; try { product = Long.parseLong(StringUtils.reverse(encodedId), 35); } catch (Exception e) { throw new IllegalArgumentException(); } if ( 0 != product % multiplier || product < 0) { throw new IllegalArgumentException(); } return product/multiplier; } }

    Read the article

  • What is a flexible, hybrid python collection object?

    - by Naveen
    As a way to get used to python, I am trying to translate some of my code to python from Autohotkey_L. I am immediately running into tons of choices for collection objects. Can you help me figure out a built in type or a 3rd party contributed type that has as much as possible, the functionality of the AutoHotkey_L object type and its methods. AutoHotkey_L Objects have features of a python dict, list, and a class instance. I understand that there are tradeoffs for space and speed, but I am just interested in functionality rather than optimization issues.

    Read the article

  • Why would I need a using statement to Libary B extn methods, if they're used in Library A & it's Li

    - by Greg
    Hi, I have: Main Program Class - uses Library A Library A - has partial classes which mix in methods from Library B Library B - mix in methods & interfaces Why would I need a using statement to LibaryB just to get their extension methods working in the main class? That is given that it's Library B that defines the classes that will be extended. EDIT - Except from code // *** PROGRAM *** using TopologyDAL; using Topology; // *** THIS WAS NEEDED TO GET EXTN METHODS APPEARING *** class Program { static void Main(string[] args) { var context = new Model1Container(); Node myNode; // ** trying to get myNode mixin methods to appear seems to need using line to point to Library B *** } } // ** LIBRARY A namespace TopologyDAL { public partial class Node { // Auto generated from EF } public partial class Node : INode<int> // to add extension methods from Library B { public int Key } } // ** LIBRARY B namespace ToplogyLibrary { public static class NodeExtns { public static void FromNodeMixin<T>(this INode<T> node) { // XXXX } } public interface INode<T> { // Properties T Key { get; } // Methods } }

    Read the article

  • Accessing C# Variables in JavaScript

    - by mshahbazm
    I am Developing Windows 8 application in which i have to access variables of C# class in java script function, But Unfortunately i don not know how to do this: My C# class code is: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Pakistan_Tour { public class UniversalValues { public static double xC; public static double yC; public static int selectedcity; public int retcity() { return selectedcity; } public void setcity(int val) { selectedcity=val; } public void setxy(double x, double y) { xC = x; yC = y; } public double getx() { return xC; } public double gety() { return yC; } } } I have to access the value of variables: xC and yc in java script I am doing like: function initialize() { var x = "<%=xC%>"; var y = "<%=yC%>"; } but is not working, Kindly help me with this, Thanks in advance.

    Read the article

< Previous Page | 301 302 303 304 305 306 307 308 309 310 311 312  | Next Page >