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  • controller path not found for static images? asp.net mvc routing issue?

    - by rksprst
    I have an image folder stored at ~/Content/Images/ I am loading these images via <img src="/Content/Images/Image.png" /> Recently, the images aren't loading and I am getting the following errors in my error log. What's weird is that some images load fine, while others do not load. Anyone have any idea what is wrong with my routes? Am I missing an ignore route for the /Content/ folder? I am also getting the same error for favicon.ico and a bunch of other image files... <Fatal> -- 3/25/2010 2:32:38 AM -- System.Web.HttpException: The controller for path '/Content/Images/box_bottom.png' could not be found or it does not implement IController. at System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(Type controllerType) at System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) at System.Web.Mvc.MvcHandler.ProcessRequest(HttpContextBase httpContext) at System.Web.Mvc.MvcHandler.ProcessRequest(HttpContext httpContext) at System.Web.Mvc.MvcHandler.System.Web.IHttpHandler.ProcessRequest(HttpContext httpContext) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) My current routes look like this: routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = "" } // Parameter defaults ); routes.MapRoute( "ControllerDefault", // Route name "{controller}/project/{projectid}/{action}/{searchid}", // URL with parameters new { controller = "Listen", action = "Index", searchid = "" } // Parameter defaults ); Thanks!

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  • What makes static initialization functions good, bad, or otherwise?

    - by Richard Levasseur
    Suppose you had code like this: _READERS = None _WRITERS = None def Init(num_readers, reader_params, num_writers, writer_params, ...args...): ...logic... _READERS = new ReaderPool(num_readers, reader_params) _WRITERS = new WriterPool(num_writers, writer_params) ...more logic... class Doer: def __init__(...args...): ... def Read(self, ...args...): c = _READERS.get() try: ...work with conn finally: _READERS.put(c) def Writer(...): ...similar to Read()... To me, this is a bad pattern to follow, some cons: Doers can be created without its preconditions being satisfied The code isn't easily testable because ConnPool can't be directly mocked out. Init has to be called right the first time. If its changed so it can be called multiple times, extra logic has to be added to check if variables are already defined, and lots of NULL values have to be passed around to skip re-initializing. In the event of threads, the above becomes more complicated by adding locking Globals aren't being used to communicate state (which isn't strictly bad, but a code smell) On the other hand, some pros: its very convenient to call Init(5, "user/pass", 2, "user/pass") It simple and "clean" Personally, I think the cons outweigh the pros, that is, testability and assured preconditions outweigh simplicity and convenience.

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  • Android: NullPointerException error in getting data in database

    - by Gil Viernes Marcelo
    This what happens in the system. 1. Admin login this is in other activity but i will not post it coz it has nothing to do with this (no problem) 2. Register user in system (using database no problem) 3. Click add user button (where existing user who register must display its name in ListView) Problem: When I click adduser to see if the system registered the user, it force close. CurrentUser.java package com.example.istronggyminstructor; import java.util.ArrayList; import android.os.Bundle; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.database.Cursor; import android.view.Gravity; import android.view.LayoutInflater; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.view.WindowManager; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.FrameLayout; import android.widget.ListView; import android.widget.PopupWindow; import android.widget.TextView; import android.widget.Toast; import java.util.ArrayList; import java.util.List; import java.util.Random; import com.example.istronggyminstructor.registeredUserList.Users; import android.content.ContentValues; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; public class CurrentUsers extends Activity { private Button register; private Button adduser; EditText getusertext, getpass, getweight, textdisp; View popupview, popupview2; public static ArrayList<String> ArrayofName = new ArrayList<String>(); protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_current_users); register = (Button) findViewById(R.id.regbut); adduser = (Button) findViewById(R.id.addbut); register.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { LayoutInflater inflator = (LayoutInflater) getBaseContext() .getSystemService(LAYOUT_INFLATER_SERVICE); popupview = inflator.inflate(R.layout.popup, null); final PopupWindow popupWindow = new PopupWindow(popupview, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); popupWindow.showAtLocation(popupview, Gravity.CENTER, 0, 0); popupWindow.setFocusable(true); popupWindow.update(); Button dismissbtn = (Button) popupview.findViewById(R.id.close); dismissbtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { popupWindow.dismiss(); } }); popupWindow.showAsDropDown(register, 50, -30); } }); //Thread.setDefaultUncaughtExceptionHandler(new forceclose(this)); } public void registerUser(View v) { EditText username = (EditText) popupview.findViewById(R.id.usertext); EditText password = (EditText) popupview .findViewById(R.id.passwordtext); EditText weight = (EditText) popupview.findViewById(R.id.weight); String getUsername = username.getText().toString(); String getPassword = password.getText().toString(); String getWeight = weight.getText().toString(); dataHandler dbHandler = new dataHandler(this, null, null, 1); Users user = new Users(getUsername, getPassword, Integer.parseInt(getWeight)); dbHandler.addUsers(user); Toast.makeText(getApplicationContext(), "Registering...", Toast.LENGTH_SHORT).show(); } public void onClick_addUser(View v) { LayoutInflater inflator = (LayoutInflater) getBaseContext() .getSystemService(LAYOUT_INFLATER_SERVICE); popupview2 = inflator.inflate(R.layout.popup2, null); final PopupWindow popupWindow = new PopupWindow(popupview2, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); popupWindow.showAtLocation(popupview2, Gravity.CENTER, 0, -10); popupWindow.setFocusable(true); popupWindow.update(); Button dismissbtn = (Button) popupview2.findViewById(R.id.close2); dismissbtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { popupWindow.dismiss(); } }); popupWindow.showAsDropDown(register, 50, -30); dataHandler dbHandler = new dataHandler(this, null, null, 1); dbHandler.getAllUsers(); ListView list = (ListView)findViewById(R.layout.popup2); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, ArrayofName); list.setAdapter(adapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.current_users, menu); return true; } } registeredUserList.java package com.example.istronggyminstructor; public class registeredUserList { public static class Users { private static int _id; private static String _users; private static String _password; private static int _weight; private static String[] _workoutlists; private static int _score; public Users() { } public Users(String username, String password, int weight) { _users = username; _password = password; _weight = weight; } public int getId() { return _id; } public static void setId(int id) { _id = id; } public String getUsers() { return _users; } public static void setUsers(String users) { _users = users; } public String getPassword(){ return _password; } public void setPassword(String password){ _password = password; } public int getWeight(){ return _weight; } public static void setWeight(int weight){ _weight = weight; } public String[] getWorkoutLists(){ return _workoutlists; } public void setWorkoutLists(String[] workoutlists){ _workoutlists = workoutlists; } public int score(){ return _score; } public void score(int score){ _score = score; } } } dataHandler.java package com.example.istronggyminstructor; import java.util.ArrayList; import java.util.List; import com.example.istronggyminstructor.registeredUserList.Users; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; public class dataHandler extends SQLiteOpenHelper { private static final int DATABASE_VERSION = 1; private static final String DATABASE_NAME = "userInfo.db"; public static final String TABLE_USERINFO = "user"; public static final String COLUMN_ID = "_id"; public static final String COLUMN_USERNAME = "username"; public static final String COLUMN_PASSWORD = "password"; public static final String COLUMN_WEIGHT = "weight"; public dataHandler(Context context, String name, CursorFactory factory, int version) { super(context, DATABASE_NAME, factory, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { String CREATE_USER_TABLE = "CREATE TABLE " + TABLE_USERINFO + " (" + COLUMN_ID + " INTEGER PRIMARY KEY, " + COLUMN_USERNAME + " TEXT," + COLUMN_PASSWORD + " TEXT, " + COLUMN_WEIGHT + " INTEGER " + ");"; db.execSQL(CREATE_USER_TABLE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL("DROP TABLE IF EXISTS " + TABLE_USERINFO); onCreate(db); } public void addUsers(Users user) { ContentValues values = new ContentValues(); values.put(COLUMN_USERNAME, user.getUsers()); values.put(COLUMN_PASSWORD, user.getPassword()); values.put(COLUMN_WEIGHT, user.getWeight()); SQLiteDatabase db = this.getWritableDatabase(); db.insert(TABLE_USERINFO, null, values); db.close(); } public Users findUsers(String username) { String query = "Select * FROM " + TABLE_USERINFO + " WHERE " + COLUMN_USERNAME + " = \"" + username + "\""; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(query, null); Users user = new Users(); if (cursor.moveToFirst()) { cursor.moveToFirst(); Users.setUsers(cursor.getString(1)); //Users.setWeight(Integer.parseInt(cursor.getString(3))); not yet needed cursor.close(); } else { user = null; } db.close(); return user; } public List<Users> getAllUsers(){ List<Users> user = new ArrayList(); String selectQuery = "SELECT * FROM " + TABLE_USERINFO; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(selectQuery, null); if (cursor.moveToFirst()) { do { Users users = new Users(); users.setUsers(cursor.getString(1)); String name = cursor.getString(1); CurrentUsers.ArrayofName.add(name); // Adding contact to list user.add(users); } while (cursor.moveToNext()); } // return user list return user; } public boolean deleteUsers(String username) { boolean result = false; String query = "Select * FROM " + TABLE_USERINFO + " WHERE " + COLUMN_USERNAME + " = \"" + username + "\""; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(query, null); Users user = new Users(); if (cursor.moveToFirst()) { Users.setId(Integer.parseInt(cursor.getString(0))); db.delete(TABLE_USERINFO, COLUMN_ID + " = ?", new String[] { String.valueOf(user.getId()) }); cursor.close(); result = true; } db.close(); return result; } } Logcat 08-20 03:23:23.293: E/AndroidRuntime(16363): FATAL EXCEPTION: main 08-20 03:23:23.293: E/AndroidRuntime(16363): java.lang.IllegalStateException: Could not execute method of the activity 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.view.View$1.onClick(View.java:3599) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.view.View.performClick(View.java:4204) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.view.View$PerformClick.run(View.java:17355) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.os.Handler.handleCallback(Handler.java:725) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.os.Handler.dispatchMessage(Handler.java:92) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.os.Looper.loop(Looper.java:137) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.app.ActivityThread.main(ActivityThread.java:5041) 08-20 03:23:23.293: E/AndroidRuntime(16363): at java.lang.reflect.Method.invokeNative(Native Method) 08-20 03:23:23.293: E/AndroidRuntime(16363): at java.lang.reflect.Method.invoke(Method.java:511) 08-20 03:23:23.293: E/AndroidRuntime(16363): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 08-20 03:23:23.293: E/AndroidRuntime(16363): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 08-20 03:23:23.293: E/AndroidRuntime(16363): at dalvik.system.NativeStart.main(Native Method) 08-20 03:23:23.293: E/AndroidRuntime(16363): Caused by: java.lang.reflect.InvocationTargetException 08-20 03:23:23.293: E/AndroidRuntime(16363): at java.lang.reflect.Method.invokeNative(Native Method) 08-20 03:23:23.293: E/AndroidRuntime(16363): at java.lang.reflect.Method.invoke(Method.java:511) 08-20 03:23:23.293: E/AndroidRuntime(16363): at android.view.View$1.onClick(View.java:3594) 08-20 03:23:23.293: E/AndroidRuntime(16363): ... 11 more 08-20 03:23:23.293: E/AndroidRuntime(16363): Caused by: java.lang.NullPointerException 08-20 03:23:23.293: E/AndroidRuntime(16363): at com.example.istronggyminstructor.CurrentUsers.onClick_addUser(CurrentUsers.java:118) 08-20 03:23:23.293: E/AndroidRuntime(16363): ... 14 more

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  • How can I compile GCC as a static binary?

    - by CaCl
    How can I compile the GCC Compiler so that I can pull the entire thing over to another system and use the program? I don't mind pulling in other files as well, but is there a way to gather all the required system libs as well? The OS and Arch will remain constant across the different systems, but one may contain Slackware where the other contains Debian.

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  • Avoiding Service Locator with AutoFac 2

    - by Page Brooks
    I'm building an application which uses AutoFac 2 for DI. I've been reading that using a static IoCHelper (Service Locator) should be avoided. IoCHelper.cs public static class IoCHelper { private static AutofacDependencyResolver _resolver; public static void InitializeWith(AutofacDependencyResolver resolver) { _resolver = resolver; } public static T Resolve<T>() { return _resolver.Resolve<T>(); } } From answers to a previous question, I found a way to help reduce the need for using my IoCHelper in my UnitOfWork through the use of Auto-generated Factories. Continuing down this path, I'm curious if I can completely eliminate my IoCHelper. Here is the scenario: I have a static Settings class that serves as a wrapper around my configuration implementation. Since the Settings class is a dependency to a majority of my other classes, the wrapper keeps me from having to inject the settings class all over my application. Settings.cs public static class Settings { public static IAppSettings AppSettings { get { return IoCHelper.Resolve<IAppSettings>(); } } } public interface IAppSettings { string Setting1 { get; } string Setting2 { get; } } public class AppSettings : IAppSettings { public string Setting1 { get { return GetSettings().AppSettings["setting1"]; } } public string Setting2 { get { return GetSettings().AppSettings["setting2"]; } } protected static IConfigurationSettings GetSettings() { return IoCHelper.Resolve<IConfigurationSettings>(); } } Is there a way to handle this without using a service locator and without having to resort to injecting AppSettings into each and every class? Listed below are the 3 areas in which I keep leaning on ServiceLocator instead of constructor injection: AppSettings Logging Caching

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  • How can I fetch Google static maps with TIdHTTP?

    - by cloudstrif3
    I'm trying to return content from maps.google.com from within Delphi 2006 using the TIdHTTP component. My code is as follows procedure TForm1.GetGoogleMap(); var t_GetRequest: String; t_Source: TStringList; t_Stream: TMemoryStream; begin t_Source := TStringList.Create; try t_Stream := TMemoryStream.Create; try t_GetRequest := 'http://maps.google.com/maps/api/staticmap?' + 'center=Brooklyn+Bridge,New+York,NY' + '&zoom=14' + '&size=512x512' + '&maptype=roadmap' + '&markers=color:blue|label:S|40.702147,-74.015794' + '&markers=color:green|label:G|40.711614,-74.012318' + '&markers=color:red|color:red|label:C|40.718217,-73.998284' + '&sensor=false'; IdHTTP1.Post(t_GetRequest, t_Source, t_Stream); t_Stream.SaveToFile('google.html'); finally t_Stream.Free; end; finally t_Source.Free; end; end; However I keep getting the response HTTP/1.0 403 Forbidden. I assume this means that I don't have permission to make this request but if I copy the url into my web browser IE 8, it works fine. Is there some header information that I need or something else?

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  • How to redirect every uri calls to one controller, except some static ones?

    - by Oden
    Hey, Im using codeigniter and want to make my portal a bit more seo friendly. I have a controller (articles) witch handles every article, on my portal. The URL looks like this: example.com/articles/category-sub-category/article-name I'm using mod rewrite module to hide my index.php, and codeigniter routing to hide the controller action that handles every call. I want to hide articles too, but if i hide it, every call goes to the articles controller, and thats not what i want, because i want my url look like this: example.com/category-sub-category/article-name Ive tried it with regexp routing rules in the routes.php but i found no way to make it right.

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  • how to read a static file in .py file using django ..

    - by zjm1126
    this is my error code: text = open('/media/a.txt', 'rb').read() and my perplexed is: when i use this : text = open('a.txt', 'rb').read() it can be running but when i put the 'a.txt' to the 'media' folder, i can't running , why ? thanks IOError at / [Errno 13] file not accessible: '/media/a.txt'

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  • Why my inner class DO see a NON static variable?

    - by Roman
    Earlier I had a problem when an inner anonymous class did not see a field of the "outer" class. I needed to make a final variable to make it visible to the inner class. Now I have an opposite situation. In the "outer" class "ClientListener" I use an inner class "Thread" and the "Thread" class I have the "run" method and does see the "earPort" from the "outer" class! Why? import java.io.IOException; import java.net.*; import java.io.BufferedReader; import java.io.InputStreamReader; public class ClientsListener { private int earPort; // Constructor. public ClientsListener(int earPort) { this.earPort = earPort; } public void starListening() { Thread inputStreamsGenerator = new Thread() { public void run() { System.out.println(earPort); try { System.out.println(earPort); ServerSocket listeningSocket = new ServerSocket(earPort); Socket serverSideSocket = listeningSocket.accept(); BufferedReader in = new BufferedReader(new InputStreamReader(serverSideSocket.getInputStream())); } catch (IOException e) { System.out.println(""); } } }; inputStreamsGenerator.start(); } }

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  • Using C code in c#

    - by karthik
    When i googled to find the way to change the window style i could find the code in "C" language How can i use the snippet below in my c# application, so that i can hide the Title Bar of external application ? I have not used "C" before.. //Finds a window by class name [DllImport("USER32.DLL")] public static extern IntPtr FindWindow(string lpClassName, string lpWindowName); //Sets a window to be a child window of another window [DllImport("USER32.DLL")] public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent); //Sets window attributes [DllImport("USER32.DLL")] public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong); //Gets window attributes [DllImport("USER32.DLL")] public static extern int GetWindowLong(IntPtr hWnd, int nIndex); //assorted constants needed public static int GWL_STYLE = -16; public static int WS_CHILD = 0x40000000; //child window public static int WS_BORDER = 0x00800000; //window with border public static int WS_DLGFRAME = 0x00400000; //window with double border but no title public static int WS_CAPTION= WS_BORDER | WS_DLGFRAME; //window with a title bar /* This function sets the parent of the window with class ClassClass to the form/control the method is in. */ public void Reparent() { //get handle of parent form (.net property) IntPtr par = this.Handle; //get handle of child form (win32) IntPtr child = FindWindow("ClassClass", null); //set parent of child form SetParent(child, par); //get current window style of child form int style = GetWindowLong(child, GWL_STYLE); //take current window style and remove WS_CAPTION from it SetWindowLong(child, GWL_STYLE, (style & ~WS_CAPTION)); }

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  • What is the cheapest non-colocation way to serve about 10 static files at a rate of 100 megabits per

    - by Mark Maunder
    I've looked at Amazon S3 and it costs roughly $4746 per month for 100 megabits/s (which translates into 31,640 Gigabytes of data transferred. That's at a rate of $0.15 per gig.) I haven't found a cheaper "cloud" option. I'm curious if there's any other cloud hosting option out there cheaper than S3. Uptime is not an issue because I can build failover for most things into the browser. e.g. I can use javascript to say "if the image didn't load then go to this other URL instead." FYI I'm currently using a colocation facility which is about 30% cheaper than S3 and I'm familiar with colo prices - so this question is really about "cloud" services and by that I mean services where I don't have to worry about the infrastructure.

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  • How to remove the MenuBar of an application using windows API ?

    - by karthik
    I am using the below code to remove the Title Bar of an application, which is working perfectly for notepad. Now i want to remove the Menu Bar also. How to achieve it ? //Finds a window by class name [DllImport("USER32.DLL")] public static extern IntPtr FindWindow(string lpClassName, string lpWindowName); //Sets a window to be a child window of another window [DllImport("USER32.DLL")] public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent); //Sets window attributes [DllImport("USER32.DLL")] public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong); //Gets window attributes [DllImport("USER32.DLL")] public static extern int GetWindowLong(IntPtr hWnd, int nIndex); [DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)] static extern IntPtr FindWindowByCaption(IntPtr ZeroOnly, string lpWindowName); //assorted constants needed public static int GWL_STYLE = -16; public static int WS_BORDER = 0x00800000; //window with border public static int WS_DLGFRAME = 0x00400000; //window with double border but no title public static int WS_CAPTION = WS_BORDER | WS_DLGFRAME; //window with a title bar public void WindowsReStyle() { Process[] Procs = Process.GetProcesses(); foreach (Process proc in Procs) { if (proc.ProcessName.StartsWith("notepad")) { IntPtr pFoundWindow = proc.MainWindowHandle; int style = GetWindowLong(pFoundWindow, GWL_STYLE); SetWindowLong(pFoundWindow, GWL_STYLE, (style & ~WS_CAPTION)); } } }

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  • Is it possible to have a Shared/Static Dependency Property?

    - by Matt H.
    [using VB.NET, but I can easily read C# code in responses] I have a class called QuestionClipboard with ALL shared methods/properties. I previously had a QuesitonClipboard.doesClipboardHaveContent function that returned true/false if there was a Object on my 'clipboard'. I'd prefer to implement a Dependency Property so I can allow this true/false value to participate in data binding. The "GetValue(dp as DependencyProperty)" method requires an object instance, which would mean that my Property CAN'T be shared! Here is what the code would look like in my perfect world... Of course, the word "Shared" before the property declaration renders this code useless. Private Shared clipboardHasContentPropertyKey As DependencyPropertyKey = DependencyProperty.RegisterReadOnly("clipboardHasContent", GetType(Boolean), GetType(QuestionClipboard), _ New PropertyMetadata(False, Nothing, New CoerceValueCallback(AddressOf coerceClipboardHasContent))) Private Shared clipboardHasContentProperty As DependencyProperty = clipboardHasContentPropertyKey.DependencyProperty Public SHARED Property clipboardHasContent As Boolean Get Return GetValue(clipboardHasContentProperty) End Get Set(ByVal value As Boolean) SetValue(value) End Set End Property

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  • What is wrong with locking non-static fields? What is the correct way to lock a particular instance?

    - by smartcaveman
    Why is it considered bad practice to lock non-static fields? And, if I am not locking non-static fields, then how do I lock an instance method without locking the method on all other instances of the same or derived class? I wrote an example to make my question more clear. public abstract class BaseClass { private readonly object NonStaticLockObject = new object(); private static readonly object StaticLockObject = new object(); protected void DoThreadSafeAction<T>(Action<T> action) where T: BaseClass { var derived = this as T; if(derived == null) { throw new Exception(); } lock(NonStaticLockObject) { action(derived); } } } public class DerivedClass :BaseClass { private readonly Queue<object> _queue; public void Enqueue(object obj) { DoThreadSafeAction<DerivedClass>(x=>x._queue.Enqueue(obj)); } } If I make the lock on the StaticLockObject, then the DoThreadSafeAction method will be locked for all instances of all classes that derive from BaseClass and that is not what I want. I want to make sure that no other threads can call a method on a particular instance of an object while it is locked.

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  • Is there a term for this concept, and does it exist in a static-typed language?

    - by Strilanc
    Recently I started noticing a repetition in some of my code. Of course, once you notice a repetition, it becomes grating. Which is why I'm asking this question. The idea is this: sometimes you write different versions of the same class: a raw version, a locked version, a read-only facade version, etc. These are common things to do to a class, but the translations are highly mechanical. Surround all the methods with lock acquires/releases, etc. In a dynamic language, you could write a function which did this to an instance of a class (eg. iterate over all the functions, replacing them with a version which acquires/releases a lock.). I think a good term for what I mean is 'reflected class'. You create a transformation which takes a class, and returns a modified-in-a-desired-way class. Synchronization is the easiest case, but there are others: make a class immutable [wrap methods so they clone, mutate the clone, and include it in the result], make a class readonly [assuming you can identify mutating methods], make a class appear to work with type A instead of type B, etc. The important part is that, in theory, these transformations make sense at compile-time. Even though an ActorModel<T> has methods which change depending on T, they depend on T in a specific way knowable at compile-time (ActorModel<T> methods would return a future of the original result type). I'm just wondering if this has been implemented in a language, and what it's called.

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  • slowAES encryption and java descryption

    - by amnon
    Hi , I've tried to implement the same steps as discussed in AES .NET but with no success , i can't seem to get java and slowAes to play toghter ... attached is my code i'm sorry i can't add more this is my first time trying to deal with encryption would appreciate any help private static final String ALGORITHM = "AES"; private static final byte[] keyValue = getKeyBytes("12345678901234567890123456789012"); private static final byte[] INIT_VECTOR = new byte[16]; private static IvParameterSpec ivSpec = new IvParameterSpec(INIT_VECTOR); public static void main(String[] args) throws Exception { String encoded = encrypt("watson?"); System.out.println(encoded); } private static Key generateKey() throws Exception { Key key = new SecretKeySpec(keyValue, ALGORITHM); // SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM); // key = keyFactory.generateSecret(new DESKeySpec(keyValue)); return key; } private static byte[] getKeyBytes(String key) { byte[] hash = DigestUtils.sha(key); byte[] saltedHash = new byte[16]; System.arraycopy(hash, 0, saltedHash, 0, 16); return saltedHash; } public static String encrypt(String valueToEnc) throws Exception { Key key = generateKey(); Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding"); c.init(Cipher.ENCRYPT_MODE, key,ivSpec); byte[] encValue = c.doFinal(valueToEnc.getBytes()); String encryptedValue = new BASE64Encoder().encode(encValue); return encryptedValue; } public static String decrypt(String encryptedValue) throws Exception { Key key = generateKey(); Cipher c = Cipher.getInstance(ALGORITHM); c.init(Cipher.DECRYPT_MODE, key); byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedValue); byte[] decValue = c.doFinal(decordedValue); String decryptedValue = new String(decValue); return decryptedValue; } the bytes returned are different thanks in advance .

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  • What's a good way to parameterize "static" content (e.g. CSS) in a Tomcat webapp?

    - by Steven Huwig
    Some of our CSS files contain parameters that can vary based on the deployment location (dev, QA, prod). For example: background: url(#DOJO_PATH#/dijit/themes...) to avoid hardcoding a path to a particular CDN or locally-hosted Dojo installation. These values are textually substituted with the real values by a deployment script, when it copies the contents of the webapp into the Tomcat webapps directory. That way the same deployment archive file (WAR + TAR file containing other configuration) can be deployed to dev, QA, and prod, with the varying parameters provided by environment-specific configuration files. However, I'd like to make the contents of the WAR (including the templatized CSS files) independent of this in-house deployment script. Since we don't really have control over the deployment script, all I can think to do is configure Tomcat with #DOJO_PATH# etc. as environment variables in the application's context.xml, and use Tomcat to insert those parameters into the CSS at runtime. I could make the CSS files into generated JSPs, but it seems a little ugly to me. Moreover, the substitution only needs to be done once per application deployment, so repeatedly dynamically generating the stylesheets using JSP will be rather wasteful. Does anyone have any alternative ideas or tools to use for this? We're committed to Tomcat and to substituting these parameters at deployment or at runtime (that is, not at build time).

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