Search Results

Search found 48020 results on 1921 pages for 'void return'.

Page 69/1921 | < Previous Page | 65 66 67 68 69 70 71 72 73 74 75 76  | Next Page >

  • Error "Input length must be multiple of 8 when decrypting with padded cipher"

    - by Ross Peoples
    I am trying to move a project from C# to Java for a learning exercise. I am still very new to Java, but I have a TripleDES class in C# that encrypts strings and returns a string value of the encrypted byte array. Here is my C# code: using System; using System.IO; using System.Collections.Generic; using System.Security.Cryptography; using System.Text; namespace tDocc.Classes { /// <summary> /// Triple DES encryption class /// </summary> public static class TripleDES { private static byte[] key = { 110, 32, 73, 24, 125, 66, 75, 18, 79, 150, 211, 122, 213, 14, 156, 136, 171, 218, 119, 240, 81, 142, 23, 4 }; private static byte[] iv = { 25, 117, 68, 23, 99, 78, 231, 219 }; /// <summary> /// Encrypt a string to an encrypted byte array /// </summary> /// <param name="plainText">Text to encrypt</param> /// <returns>Encrypted byte array</returns> public static byte[] Encrypt(string plainText) { UTF8Encoding utf8encoder = new UTF8Encoding(); byte[] inputInBytes = utf8encoder.GetBytes(plainText); TripleDESCryptoServiceProvider tdesProvider = new TripleDESCryptoServiceProvider(); ICryptoTransform cryptoTransform = tdesProvider.CreateEncryptor(key, iv); MemoryStream encryptedStream = new MemoryStream(); CryptoStream cryptStream = new CryptoStream(encryptedStream, cryptoTransform, CryptoStreamMode.Write); cryptStream.Write(inputInBytes, 0, inputInBytes.Length); cryptStream.FlushFinalBlock(); encryptedStream.Position = 0; byte[] result = new byte[encryptedStream.Length]; encryptedStream.Read(result, 0, (int)encryptedStream.Length); cryptStream.Close(); return result; } /// <summary> /// Decrypt a byte array to a string /// </summary> /// <param name="inputInBytes">Encrypted byte array</param> /// <returns>Decrypted string</returns> public static string Decrypt(byte[] inputInBytes) { UTF8Encoding utf8encoder = new UTF8Encoding(); TripleDESCryptoServiceProvider tdesProvider = new TripleDESCryptoServiceProvider(); ICryptoTransform cryptoTransform = tdesProvider.CreateDecryptor(key, iv); MemoryStream decryptedStream = new MemoryStream(); CryptoStream cryptStream = new CryptoStream(decryptedStream, cryptoTransform, CryptoStreamMode.Write); cryptStream.Write(inputInBytes, 0, inputInBytes.Length); cryptStream.FlushFinalBlock(); decryptedStream.Position = 0; byte[] result = new byte[decryptedStream.Length]; decryptedStream.Read(result, 0, (int)decryptedStream.Length); cryptStream.Close(); UTF8Encoding myutf = new UTF8Encoding(); return myutf.GetString(result); } /// <summary> /// Decrypt an encrypted string /// </summary> /// <param name="text">Encrypted text</param> /// <returns>Decrypted string</returns> public static string DecryptText(string text) { if (text == "") { return text; } return Decrypt(Convert.FromBase64String(text)); } /// <summary> /// Encrypt a string /// </summary> /// <param name="text">Unencrypted text</param> /// <returns>Encrypted string</returns> public static string EncryptText(string text) { if (text == "") { return text; } return Convert.ToBase64String(Encrypt(text)); } } /// <summary> /// Random number generator /// </summary> public static class RandomGenerator { /// <summary> /// Generate random number /// </summary> /// <param name="length">Number of randomizations</param> /// <returns>Random number</returns> public static int GenerateNumber(int length) { byte[] randomSeq = new byte[length]; new RNGCryptoServiceProvider().GetBytes(randomSeq); int code = Environment.TickCount; foreach (byte b in randomSeq) { code += (int)b; } return code; } } /// <summary> /// Hash generator class /// </summary> public static class Hasher { /// <summary> /// Hash type /// </summary> public enum eHashType { /// <summary> /// MD5 hash. Quick but collisions are more likely. This should not be used for anything important /// </summary> MD5 = 0, /// <summary> /// SHA1 hash. Quick and secure. This is a popular method for hashing passwords /// </summary> SHA1 = 1, /// <summary> /// SHA256 hash. Slower than SHA1, but more secure. Used for encryption keys /// </summary> SHA256 = 2, /// <summary> /// SHA348 hash. Even slower than SHA256, but offers more security /// </summary> SHA348 = 3, /// <summary> /// SHA512 hash. Slowest but most secure. Probably overkill for most applications /// </summary> SHA512 = 4, /// <summary> /// Derrived from MD5, but only returns 12 digits /// </summary> Digit12 = 5 } /// <summary> /// Hashes text using a specific hashing method /// </summary> /// <param name="text">Input text</param> /// <param name="hash">Hash method</param> /// <returns>Hashed text</returns> public static string GetHash(string text, eHashType hash) { if (text == "") { return text; } if (hash == eHashType.MD5) { MD5CryptoServiceProvider hasher = new MD5CryptoServiceProvider(); return ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); } else if (hash == eHashType.SHA1) { SHA1Managed hasher = new SHA1Managed(); return ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); } else if (hash == eHashType.SHA256) { SHA256Managed hasher = new SHA256Managed(); return ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); } else if (hash == eHashType.SHA348) { SHA384Managed hasher = new SHA384Managed(); return ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); } else if (hash == eHashType.SHA512) { SHA512Managed hasher = new SHA512Managed(); return ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); } else if (hash == eHashType.Digit12) { MD5CryptoServiceProvider hasher = new MD5CryptoServiceProvider(); string newHash = ByteToHex(hasher.ComputeHash(Encoding.ASCII.GetBytes(text))); return newHash.Substring(0, 12); } return ""; } /// <summary> /// Generates a hash based on a file's contents. Used for detecting changes to a file and testing for duplicate files /// </summary> /// <param name="info">FileInfo object for the file to be hashed</param> /// <param name="hash">Hash method</param> /// <returns>Hash string representing the contents of the file</returns> public static string GetHash(FileInfo info, eHashType hash) { FileStream hashStream = new FileStream(info.FullName, FileMode.Open, FileAccess.Read); string hashString = ""; if (hash == eHashType.MD5) { MD5CryptoServiceProvider hasher = new MD5CryptoServiceProvider(); hashString = ByteToHex(hasher.ComputeHash(hashStream)); } else if (hash == eHashType.SHA1) { SHA1Managed hasher = new SHA1Managed(); hashString = ByteToHex(hasher.ComputeHash(hashStream)); } else if (hash == eHashType.SHA256) { SHA256Managed hasher = new SHA256Managed(); hashString = ByteToHex(hasher.ComputeHash(hashStream)); } else if (hash == eHashType.SHA348) { SHA384Managed hasher = new SHA384Managed(); hashString = ByteToHex(hasher.ComputeHash(hashStream)); } else if (hash == eHashType.SHA512) { SHA512Managed hasher = new SHA512Managed(); hashString = ByteToHex(hasher.ComputeHash(hashStream)); } hashStream.Close(); hashStream.Dispose(); hashStream = null; return hashString; } /// <summary> /// Converts a byte array to a hex string /// </summary> /// <param name="data">Byte array</param> /// <returns>Hex string</returns> public static string ByteToHex(byte[] data) { StringBuilder builder = new StringBuilder(); foreach (byte hashByte in data) { builder.Append(string.Format("{0:X1}", hashByte)); } return builder.ToString(); } /// <summary> /// Converts a hex string to a byte array /// </summary> /// <param name="hexString">Hex string</param> /// <returns>Byte array</returns> public static byte[] HexToByte(string hexString) { byte[] returnBytes = new byte[hexString.Length / 2]; for (int i = 0; i <= returnBytes.Length - 1; i++) { returnBytes[i] = byte.Parse(hexString.Substring(i * 2, 2), System.Globalization.NumberStyles.HexNumber); } return returnBytes; } } } And her is what I've got for Java code so far, but I'm getting the error "Input length must be multiple of 8 when decrypting with padded cipher" when I run the test on this: import java.security.InvalidAlgorithmParameterException; import java.security.InvalidKeyException; import javax.crypto.Cipher; import javax.crypto.NoSuchPaddingException; import javax.crypto.SecretKey; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; import com.tdocc.utils.Base64; public class TripleDES { private static byte[] keyBytes = { 110, 32, 73, 24, 125, 66, 75, 18, 79, (byte)150, (byte)211, 122, (byte)213, 14, (byte)156, (byte)136, (byte)171, (byte)218, 119, (byte)240, 81, (byte)142, 23, 4 }; private static byte[] ivBytes = { 25, 117, 68, 23, 99, 78, (byte)231, (byte)219 }; public static String encryptText(String plainText) { try { if (plainText.isEmpty()) return plainText; return Base64.decode(TripleDES.encrypt(plainText)).toString(); } catch (Exception e) { e.printStackTrace(); } return null; } public static byte[] encrypt(String plainText) throws InvalidKeyException, InvalidAlgorithmParameterException, NoSuchPaddingException { try { final SecretKey key = new SecretKeySpec(keyBytes, "DESede"); final IvParameterSpec iv = new IvParameterSpec(ivBytes); final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key, iv); final byte[] plainTextBytes = plainText.getBytes("utf-8"); final byte[] cipherText = cipher.doFinal(plainTextBytes); return cipherText; } catch (Exception e) { e.printStackTrace(); } return null; } public static String decryptText(String message) { try { if (message.isEmpty()) return message; else return TripleDES.decrypt(message.getBytes()); } catch (Exception e) { e.printStackTrace(); } return null; } public static String decrypt(byte[] message) { try { final SecretKey key = new SecretKeySpec(keyBytes, "DESede"); final IvParameterSpec iv = new IvParameterSpec(ivBytes); final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, key, iv); final byte[] plainText = cipher.doFinal(message); return plainText.toString(); } catch (Exception e) { e.printStackTrace(); } return null; } }

    Read the article

  • How can I force PHP's fopen() to return the current version of a web page?

    - by Edward Tanguay
    The current content of this google docs page is: However, when reading this page with the following PHP fopen() script, I get an older, cached version: I've tried two solutions proposed in this question (a random attribute and using POST) and I also tried clearstatcache() but I always get the cached version of the web page. What do I have to change in the following script so that fopen() returns the current version of the web page? <?php $url = 'http://docs.google.com/View?id=dc7gj86r_32g68627ff&amp;rand=' . getRandomDigits(10); echo $url . '<hr/>'; echo loadFile($url); function loadFile($sFilename) { clearstatcache(); if (floatval(phpversion()) >= 4.3) { $sData = file_get_contents($sFilename); } else { if (!file_exists($sFilename)) return -3; $opts = array('http' => array( 'method' => 'POST', 'content'=>'' ) ); $context = stream_context_create($opts); $rHandle = fopen($sFilename, 'r'); if (!$rHandle) return -2; $sData = ''; while(!feof($rHandle)) $sData .= fread($rHandle, filesize($sFilename)); fclose($rHandle); } return $sData; } function getRandomDigits($numberOfDigits) { $r = ""; for($i=1; $i<=$numberOfDigits; $i++) { $nr=rand(0,9); $r .= $nr; } return $r; } ?>

    Read the article

  • Return a list of imported Python modules used in a script?

    - by Jono Bacon
    Hi All, I am writing a program that categorizes a list of Python files by which modules they import. As such I need to scan the collection of .py files ad return a list of which modules they import. As an example, if one of the files I import has the following lines: import os import sys, gtk I would like it to return: ["os", "sys", "gtk"] I played with modulefinder and wrote: from modulefinder import ModuleFinder finder = ModuleFinder() finder.run_script('testscript.py') print 'Loaded modules:' for name, mod in finder.modules.iteritems(): print '%s ' % name, but this returns more than just the modules used in the script. As an example in a script which merely has: import os print os.getenv('USERNAME') The modules returned from the ModuleFinder script return: tokenize heapq __future__ copy_reg sre_compile _collections cStringIO _sre functools random cPickle __builtin__ subprocess cmd gc __main__ operator array select _heapq _threading_local abc _bisect posixpath _random os2emxpath tempfile errno pprint binascii token sre_constants re _abcoll collections ntpath threading opcode _struct _warnings math shlex fcntl genericpath stat string warnings UserDict inspect repr struct sys pwd imp getopt readline copy bdb types strop _functools keyword thread StringIO bisect pickle signal traceback difflib marshal linecache itertools dummy_thread posix doctest unittest time sre_parse os pdb dis ...whereas I just want it to return 'os', as that was the module used in the script. Can anyone help me achieve this?

    Read the article

  • What is the return type for a anonymous linq query select? What is the best way to send this data ba

    - by punkouter
    This is a basic question. I have the basic SL4/RIA project set up and I want to create a new method in the domain service and return some data from it. I am unsure the proper easiest way to do this.. Should I wrap it up in a ToList()? I am unclear how to handle this anonymous type that was create.. what is the easiest way to return this data? public IQueryable<ApplicationLog> GetApplicationLogsGrouped() { var x = from c in ObjectContext.ApplicationLogs let dt = c.LogDate group c by new { y = dt.Value.Year, m = dt.Value.Month, d = dt.Value.Day } into mygroup select new { aaa = mygroup.Key, ProductCount = mygroup.Count() }; return x; // return this.ObjectContext.ApplicationLogs.Where(r => r.ApplicationID < 50); } Cannot implicitly convert type 'System.Linq.IQueryable<AnonymousType#1>' to 'System.Linq.IQueryable<CapRep4.Web.ApplicationLog>'. An explicit conversion exists (are you missing a cast?) 58 20 CapRep4.Web

    Read the article

  • Return a list of important Python modules in a script?

    - by Jono Bacon
    Hi All, I am writing a program that categorizes a list of Python files by which modules they import. As such I need to scan the collection of .py files ad return a list of which modules they import. As an example, if one of the files I import has the following lines: import os import sys, gtk I would like it to return: ["os", "sys", "gtk"] I played with modulefinder and wrote: from modulefinder import ModuleFinder finder = ModuleFinder() finder.run_script('testscript.py') print 'Loaded modules:' for name, mod in finder.modules.iteritems(): print '%s ' % name, but this returns more than just the modules used in the script. As an example in a script which merely has: import os print os.getenv('USERNAME') The modules returned from the ModuleFinder script return: tokenize heapq __future__ copy_reg sre_compile _collections cStringIO _sre functools random cPickle __builtin__ subprocess cmd gc __main__ operator array select _heapq _threading_local abc _bisect posixpath _random os2emxpath tempfile errno pprint binascii token sre_constants re _abcoll collections ntpath threading opcode _struct _warnings math shlex fcntl genericpath stat string warnings UserDict inspect repr struct sys pwd imp getopt readline copy bdb types strop _functools keyword thread StringIO bisect pickle signal traceback difflib marshal linecache itertools dummy_thread posix doctest unittest time sre_parse os pdb dis ...whereas I just want it to return 'os', as that was the module used in the script. Can anyone help me achieve this?

    Read the article

  • Function should return float, but it gets messed up!

    - by Andre
    Hi guys, I'm going crazy here. I have a function that should return a float number: - (float) getHue:(UIColor *)original { NSLog(@"getHue"); const CGFloat *componentColors = CGColorGetComponents(original.CGColor); float red = componentColors[0]; float green = componentColors[1]; float blue = componentColors[2]; float h = 0.0f; float maxChannel = fmax(red, fmax(green, blue)); float minChannel = fmin(red, fmin(green, blue)); if (maxChannel == minChannel) h = 0.0f; else if (maxChannel == red) h = 0.166667f * (green - blue) / (maxChannel - minChannel) + 0.000000f; else if (maxChannel == green) h = 0.166667f * (blue - red) / (maxChannel - minChannel) + 0.333333f; else if (maxChannel == blue) h = 0.166667f * (red - green) / (maxChannel - minChannel) + 0.666667f; else h = 0.0f; if (h < 0.0f) h += 1.0f; NSLog(@"getHue results: %f", h); return h; } The NSLog will trace it correctly (i.e: 0.005), but the actual return value of the function is NULL. I've tried getting that value in so many ways and it never works. float originalHue = [self getHue:original]; results in a building error, as it says: "incompatible types in initialization" float *originalHue = [self getHue:original]; results in a null return. I've tried other ways, but it never actually gets the value properly. Any thoughts? Cheers guys, Andre

    Read the article

  • How do i return a template class from a template function?

    - by LoudNPossiblyRight
    It looks logical but for some reason when i uncomment the last cout line, this code does not compile. How do i return a template class? What do i have to do to this code to make it work? #include<iostream> using namespace std; template <int x> class someclass{ public: int size; int intarr[x]; someclass():size(x){} }; template<int x, int y> int somefunc(someclass<x> A, someclass<y> B){ return ( A.size > B.size ? A.size : B.size); } template<int x, int y, int z> someclass<x> anotherfunc(someclass<y> A, someclass<z> B){ return ( A.size > B.size ? A : B); } int main(){ someclass<5> A; someclass<10> B; cout << "SIZE = " << somefunc(A,B) << endl; //cout << "SIZE = " << (anotherfunc(A,B)).size << endl; //THIS DOES NOT COMPILE return 0; }

    Read the article

  • How to use CellRenderer for GregorianCalendar?

    - by HansDampf
    So I have been trying to use the example from Tutorial and change it so it fits my program. The getColumnValue method returns the object that holds the information that is supposed to be displayed. Is this the way to go or should it rather return the actual String to be displayed. I guess not because that way I would mix the presentation with the data, which I was trying to avoid. public class IssueTableFormat implements TableFormat<Appointment> { public int getColumnCount() { return 6; } public String getColumnName(int column) { if(column == 0) return "Datum"; else if(column == 1) return "Uhrzeit"; else if(column == 2) return "Nummer"; else if(column == 3) return "Name"; else if(column == 4) return "letzte Aktion"; else if(column == 5) return "Kommentar"; throw new IllegalStateException(); } public Object getColumnValue(Appointment issue, int column) { if(column == 0) return issue.getDate(); else if(column == 1) return issue.getDate(); else if(column == 2) return issue.getSample(); else if(column == 3) return issue.getSample(); else if(column == 4) return issue.getHistory(); else if(column == 5) return issue.getComment(); throw new IllegalStateException(); } } The column 0 and 1 contain a GregorianCalendar object, but I want column 0 to show the date and 1 to show the time. So I know using cellRenderers can help here. This is what I tried. public class DateRenderer extends DefaultTableCellRenderer { public DateRenderer() { super(); } public void setValue(Object value) { GregorianCalendar g =(GregorianCalendar) value; value=g.get(GregorianCalendar.HOUR); } } But the cell doesnt show anything, what is wrong here?

    Read the article

  • How to get java singleton object manager to return any type of object?

    - by Robert
    I'm writing an interactive fiction game in java from scratch. I'm currently storing all of my game object references in a hashmap in a singleton called ObjectManager. ObjectManager has a function called get which takes an integer ID and returns the appropriate reference. The problem is that it returns a BaseObject when I need to return subclasses of BaseObject with more functionality. So, what I've done so far is I've added a getEntity function which returns BaseEntity (which is a subclass of BaseObject). However, when I need the function to return to an object that is a subclass of BaseEntity that has added, required functionality, I will need to make another function. I know there is a better way, but I don't know what it is. I know very little of design patterns, and I'm not sure which one to use here. I tried passing 'class' as a parameter, but that didn't get me anywhere. public BaseObject get(int ID){ return (BaseObject)refMap.get(ID); } public BaseEntity getEntity(int ID){ return (BaseEntity)refMap.get(ID); } Thanks, java ninjas!

    Read the article

  • Detecting Process Shutdown/Startup Events through ActivationAgents

    - by Ramkumar Menon
    @10g - This post is motivated by one of my close friends and colleague - who wanted to proactively know when a BPEL process shuts down/re-activates. This typically happens when you have a BPEL Process that has an inbound polling adapter, when the adapter loses connectivity to the source system. Or whatever causes it. One valuable suggestion came in from one of my colleagues - he suggested I write my own ActivationAgent to do the job. Well, it really worked. Here is a sample ActivationAgent that you can use. There are few methods you need to override from BaseActivationAgent, and you are on your way to receiving notifications/what not, whenever the shutdown/startup events occur. In the example below, I am retrieving the emailAddress property [that is specified in your bpel.xml activationAgent section] and use that to send out an email notification on the activation agent initialization. You could choose to do different things. But bottomline is that you can use the below-mentioned API to access the very same properties that you specify in the bpel.xml. package com.adapter.custom.activation; import com.collaxa.cube.activation.BaseActivationAgent; import com.collaxa.cube.engine.ICubeContext; import com.oracle.bpel.client.BPELProcessId; import java.util.Date; import java.util.Properties; public class LifecycleManagerActivationAgent extends BaseActivationAgent { public BPELProcessId getBPELProcessId() { return super.getBPELProcessId(); } private void handleInit() throws Exception { //Write initialization code here System.err.println("Entered initialization code...."); //e.g. String emailAddress = getActivationAgentDescriptor().getPropertyValue(emailAddress); //send an email sendEmail(emailAddress); } private void handleLoad() throws Exception { //Write load code here System.err.println("Entered load code...."); } private void handleUnload() throws Exception { //Write unload code here System.err.println("Entered unload code...."); } private void handleUninit() throws Exception { //Write uninitialization code here System.err.println("Entered uninitialization code...."); } public void init(ICubeContext icubecontext) throws Exception { super.init(icubecontext); System.err.println("Initializing LifecycleManager Activation Agent ....."); handleInit(); } public void unload(ICubeContext icubecontext) throws Exception { super.unload(icubecontext); System.err.println("Unloading LifecycleManager Activation Agent ....."); handleUnload(); } public void uninit(ICubeContext icubecontext) throws Exception{ super.uninit(icubecontext); System.err.println("Uninitializing LifecycleManager Activation Agent ....."); handleUninit(); } public String getName() { return "Lifecyclemanageractivationagent"; } public void onStateChanged(int i, ICubeContext iCubeContext) { } public void onLifeCycleChanged(int i, ICubeContext iCubeContext) { } public void onUndeployed(ICubeContext iCubeContext) { } public void onServerShutdown() { } } Once you compile this code, generate a jar file and ensure you add it to the server startup classpath. The library is ready for use after the server restarts. To use this activationAgent, add an additional activationAgent entry in the bpel.xml for the BPEL Process that you wish to monitor. After you deploy the process, the ActivationAgent object will be called back whenever the events mentioned in the overridden methods are raised. [init(), load(), unload(), uninit()]. Subsequently, your custom code is executed. Sample bpel.xml illustrating activationAgent definition and property definition. <?xml version="1.0" encoding="UTF-8"? <BPELSuitcase timestamp="1291943469921" revision="1.0" <BPELProcess wsdlPort="{http://xmlns.oracle.com/BPELTest}BPELTestPort" src="BPELTest.bpel" wsdlService="{http://xmlns.oracle.com/BPELTest}BPELTest" id="BPELTest" <partnerLinkBindings <partnerLinkBinding name="client" <property name="wsdlLocation"BPELTest.wsdl</property </partnerLinkBinding <partnerLinkBinding name="test" <property name="wsdlLocation"test.wsdl</property </partnerLinkBinding </partnerLinkBindings <activationAgents <activationAgent className="oracle.tip.adapter.fw.agent.jca.JCAActivationAgent" partnerLink="test" <property name="portType"Read_ptt</property </activationAgent <activationAgent className="com.oracle.bpel.activation.LifecycleManagerActivationAgent" partnerLink="test" <property name="emailAddress"[email protected]</property </activationAgent </activationAgents </BPELProcess </BPELSuitcase em

    Read the article

  • Java Dragging an object from one area to another [on hold]

    - by user50369
    Hello I have a game where you drag bits of food around the screen. I want to be able to click on an ingredient and drag it to another part of the screen where I release the mouse. I am new to java so I do not really know how to do this please help me Here is me code. This is the class with the mouse listeners in it: public void mousePressed(MouseEvent e) { if (e.getButton() == MouseEvent.BUTTON1) { Comp.ml = true; // placing if (manager.title == true) { if (title.r.contains(Comp.mx, Comp.my)) { title.overview = true; } else if (title.r1.contains(Comp.mx, Comp.my)) { title.options = true; } else if (title.r2.contains(Comp.mx, Comp.my)) { System.exit(0); } } if (manager.option == true) { optionsMouse(e); } mouseinventory(e); } else if (e.getButton() == MouseEvent.BUTTON3) { Comp.mr = true; } } private void mouseinventory(MouseEvent e) { if (e.getButton() == MouseEvent.BUTTON1) { } else if (e.getButton() == MouseEvent.BUTTON1) { } } @Override public void mouseReleased(MouseEvent e) { if (e.getButton() == MouseEvent.BUTTON1) { Comp.ml = false; } else if (e.getButton() == MouseEvent.BUTTON3) { Comp.mr = false; } } @Override public void mouseDragged(MouseEvent e) { for(int i = 0; i < overview.im.ing.toArray().length; i ++){ if(overview.im.ing.get(i).r.contains(Comp.mx,Comp.my)){ overview.im.ing.get(i).newx = Comp.mx; overview.im.ing.get(i).newy = Comp.my; overview.im.ing.get(i).dragged = true; }else{ overview.im.ing.get(i).dragged = false; } } } @Override public void mouseMoved(MouseEvent e) { Comp.mx = e.getX(); Comp.my = e.getY(); // System.out.println("" + Comp.my); } This is the class called ingredient public abstract class Ingrediant { public int x,y,id,lastx,lasty,newx,newy; public boolean removed = false,dragged = false; public int width; public int height; public Rectangle r = new Rectangle(x,y,width,height); public Ingrediant(){ r = new Rectangle(x,y,width,height); } public abstract void tick(); public abstract void render(Graphics g); } and this is a class which extends ingredient called hagleave public class HagLeave extends Ingrediant { private Image img; public HagLeave(int x, int y, int id) { this.x = x; this.y = y; this.newx = x; this.newy = y; this.id = id; width = 75; height = 75; r = new Rectangle(x,y,width,height); } public void tick() { r = new Rectangle(x,y,width,height); if(!dragged){ x = newx; y = newy; } } public void render(Graphics g) { ImageIcon i2 = new ImageIcon("res/ingrediants/hagleave.png"); img = i2.getImage(); g.drawImage(img, x, y, null); g.setColor(Color.red); g.drawRect(r.x, r.y, r.width, r.height); } } The arraylist is in a class called ingrediantManager: public class IngrediantsManager { public ArrayList<Ingrediant> ing = new ArrayList<Ingrediant>(); public IngrediantsManager(){ ing.add(new HagLeave(100,200,1)); ing.add(new PigHair(70,300,2)); ing.add(new GiantsToe(100,400,3)); } public void tick(){ for(int i = 0; i < ing.toArray().length; i ++){ ing.get(i).tick(); if(ing.get(i).removed){ ing.remove(i); i--; } } } public void render(Graphics g){ for(int i = 0; i < ing.toArray().length; i ++){ ing.get(i).render(g); } } }

    Read the article

  • Segfault when iterating over a map<string, string> and drawing its contents using SDL_TTF

    - by Michael Stahre
    I'm not entirely sure this question belongs on gamedev.stackexchange, but I'm technically working on a game and working with SDL, so it might not be entirely offtopic. I've written a class called DebugText. The point of the class is to have a nice way of printing values of variables to the game screen. The idea is to call SetDebugText() with the variables in question every time they change or, as is currently the case, every time the game's Update() is called. The issue is that when iterating over the map that contains my variables and their latest updated values, I get segfaults. See the comments in DrawDebugText() below, it specifies where the error happens. I've tried splitting the calls to it-first and it-second into separate lines and found that the problem doesn't always happen when calling it-first. It alters between it-first and it-second. I can't find a pattern. It doesn't fail on every call to DrawDebugText() either. It might fail on the third time DrawDebugText() is called, or it might fail on the fourth. Class header: #ifndef CLIENT_DEBUGTEXT_H #define CLIENT_DEBUGTEXT_H #include <Map> #include <Math.h> #include <sstream> #include <SDL.h> #include <SDL_ttf.h> #include "vector2.h" using std::string; using std::stringstream; using std::map; using std::pair; using game::Vector2; namespace game { class DebugText { private: TTF_Font* debug_text_font; map<string, string>* debug_text_list; public: void SetDebugText(string var, bool value); void SetDebugText(string var, float value); void SetDebugText(string var, int value); void SetDebugText(string var, Vector2 value); void SetDebugText(string var, string value); int DrawDebugText(SDL_Surface*, SDL_Rect*); void InitDebugText(); void Clear(); }; } #endif Class source file: #include "debugtext.h" namespace game { // Copypasta function for handling the toString conversion template <class T> inline string to_string (const T& t) { stringstream ss (stringstream::in | stringstream::out); ss << t; return ss.str(); } // Initializes SDL_TTF and sets its font void DebugText::InitDebugText() { if(TTF_WasInit()) TTF_Quit(); TTF_Init(); debug_text_font = TTF_OpenFont("LiberationSans-Regular.ttf", 16); TTF_SetFontStyle(debug_text_font, TTF_STYLE_NORMAL); } // Iterates over the current debug_text_list and draws every element on the screen. // After drawing with SDL you need to get a rect specifying the area on the screen that was changed and tell SDL that this part of the screen needs to be updated. this is done in the game's Draw() function // This function sets rects_to_update to the new list of rects provided by all of the surfaces and returns the number of rects in the list. These two parameters are used in Draw() when calling on SDL_UpdateRects(), which takes an SDL_Rect* and a list length int DebugText::DrawDebugText(SDL_Surface* screen, SDL_Rect* rects_to_update) { if(debug_text_list == NULL) return 0; if(!TTF_WasInit()) InitDebugText(); rects_to_update = NULL; // Specifying the font color SDL_Color font_color = {0xff, 0x00, 0x00, 0x00}; // r, g, b, unused int row_count = 0; string line; // The iterator variable map<string, string>::iterator it; // Gets the iterator and iterates over it for(it = debug_text_list->begin(); it != debug_text_list->end(); it++) { // Takes the first value (the name of the variable) and the second value (the value of the parameter in string form) //---------THIS LINE GIVES ME SEGFAULTS----- line = it->first + ": " + it->second; //------------------------------------------ // Creates a surface with the text on it that in turn can be rendered to the screen itself later SDL_Surface* debug_surface = TTF_RenderText_Solid(debug_text_font, line.c_str(), font_color); if(debug_surface == NULL) { // A standard check for errors fprintf(stderr, "Error: %s", TTF_GetError()); return NULL; } else { // If SDL_TTF did its job right, then we now set a destination rect row_count++; SDL_Rect dstrect = {5, 5, 0, 0}; // x, y, w, h dstrect.x = 20; dstrect.y = 20*row_count; // Draws the surface with the text on it to the screen int res = SDL_BlitSurface(debug_surface,NULL,screen,&dstrect); if(res != 0) { //Just an error check fprintf(stderr, "Error: %s", SDL_GetError()); return NULL; } // Creates a new rect to specify the area that needs to be updated with SDL_Rect* new_rect_to_update = (SDL_Rect*) malloc(sizeof(SDL_Rect)); new_rect_to_update->h = debug_surface->h; new_rect_to_update->w = debug_surface->w; new_rect_to_update->x = dstrect.x; new_rect_to_update->y = dstrect.y; // Just freeing the surface since it isn't necessary anymore SDL_FreeSurface(debug_surface); // Creates a new list of rects with room for the new rect SDL_Rect* newtemp = (SDL_Rect*) malloc(row_count*sizeof(SDL_Rect)); // Copies the data from the old list of rects to the new one memcpy(newtemp, rects_to_update, (row_count-1)*sizeof(SDL_Rect)); // Adds the new rect to the new list newtemp[row_count-1] = *new_rect_to_update; // Frees the memory used by the old list free(rects_to_update); // And finally redirects the pointer to the old list to the new list rects_to_update = newtemp; newtemp = NULL; } } // When the entire map has been iterated over, return the number of lines that were drawn, ie. the number of rects in the returned rect list return row_count; } // The SetDebugText used by all the SetDebugText overloads // Takes two strings, inserts them into the map as a pair void DebugText::SetDebugText(string var, string value) { if (debug_text_list == NULL) { debug_text_list = new map<string, string>(); } debug_text_list->erase(var); debug_text_list->insert(pair<string, string>(var, value)); } // Writes the bool to a string and calls SetDebugText(string, string) void DebugText::SetDebugText(string var, bool value) { string result; if (value) result = "True"; else result = "False"; SetDebugText(var, result); } // Does the same thing, but uses to_string() to convert the float void DebugText::SetDebugText(string var, float value) { SetDebugText(var, to_string(value)); } // Same as above, but int void DebugText::SetDebugText(string var, int value) { SetDebugText(var, to_string(value)); } // Vector2 is a struct of my own making. It contains the two float vars x and y void DebugText::SetDebugText(string var, Vector2 value) { SetDebugText(var + ".x", to_string(value.x)); SetDebugText(var + ".y", to_string(value.y)); } // Empties the list. I don't actually use this in my code. Shame on me for writing something I don't use. void DebugText::Clear() { if(debug_text_list != NULL) debug_text_list->clear(); } }

    Read the article

  • OData &ndash; The easiest service I can create: now with updates

    - by Jon Dalberg
    The other day I created a simple NastyWord service exposed via OData. It was read-only and used an in-memory backing store for the words. Today I’ll modify it to use a file instead of a list and I’ll accept new nasty words by implementing IUpdatable directly. The first thing to do is enable the service to accept new entries. This is done at configuration time by adding the “WriteAppend” access rule: 1: public class NastyWords : DataService<NastyWordsDataSource> 2: { 3: // This method is called only once to initialize service-wide policies. 4: public static void InitializeService(DataServiceConfiguration config) 5: { 6: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead | EntitySetRights.WriteAppend); 7: config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 8: } 9: }   Next I placed a file, NastyWords.txt, in the “App_Data” folder and added a few *choice* words to start. This required one simple change to our NastyWordDataSource.cs file: 1: public NastyWordsDataSource() 2: { 3: UpdateFromSource(); 4: } 5:   6: private void UpdateFromSource() 7: { 8: var words = File.ReadAllLines(pathToFile); 9: NastyWords = (from w in words 10: select new NastyWord { Word = w }).AsQueryable(); 11: }   Nothing too shocking here, just reading each line from the NastyWords.txt file and exposing them. Next, I implemented IUpdatable which comes with a boat-load of methods. We don’t need all of them for now since we are only concerned with allowing new values. Here are the methods we must implement, all the others throw a NotImplementedException: 1: public object CreateResource(string containerName, string fullTypeName) 2: { 3: var nastyWord = new NastyWord(); 4: pendingUpdates.Add(nastyWord); 5: return nastyWord; 6: } 7:   8: public object ResolveResource(object resource) 9: { 10: return resource; 11: } 12:   13: public void SaveChanges() 14: { 15: var intersect = (from w in pendingUpdates 16: select w.Word).Intersect(from n in NastyWords 17: select n.Word); 18:   19: if (intersect.Count() > 0) 20: throw new DataServiceException(500, "duplicate entry"); 21:   22: var lines = from w in pendingUpdates 23: select w.Word; 24:   25: File.AppendAllLines(pathToFile, 26: lines, 27: Encoding.UTF8); 28:   29: pendingUpdates.Clear(); 30:   31: UpdateFromSource(); 32: } 33:   34: public void SetValue(object targetResource, string propertyName, object propertyValue) 35: { 36: targetResource.GetType().GetProperty(propertyName).SetValue(targetResource, propertyValue, null); 37: }   I use a simple list to contain the pending updates and only commit them when the “SaveChanges” method is called. Here’s the order these methods are called in our service during an insert: CreateResource – here we just instantiate a new NastyWord and stick a reference to it in our pending updates list. SetValue – this is where the “Word” property of the NastyWord instance is set. SaveChanges – get the list of pending updates, barfing on duplicates, write them to the file and clear our pending list. ResolveResource – the newly created resource will be returned directly here since we aren’t dealing with “handles” to objects but the actual objects themselves. Not too bad, eh? I didn’t find this documented anywhere but a little bit of digging in the OData spec and use of Fiddler made it pretty easy to figure out. Here is some client code which would add a new nasty word: 1: static void Main(string[] args) 2: { 3: var svc = new ServiceReference1.NastyWordsDataSource(new Uri("http://localhost.:60921/NastyWords.svc")); 4: svc.AddToNastyWords(new ServiceReference1.NastyWord() { Word = "shat" }); 5:   6: svc.SaveChanges(); 7: }   Here’s all of the code so far for to implement the service: 1: using System; 2: using System.Collections.Generic; 3: using System.Data.Services; 4: using System.Data.Services.Common; 5: using System.Linq; 6: using System.ServiceModel.Web; 7: using System.Web; 8: using System.IO; 9: using System.Text; 10:   11: namespace ONasty 12: { 13: [DataServiceKey("Word")] 14: public class NastyWord 15: { 16: public string Word { get; set; } 17: } 18:   19: public class NastyWordsDataSource : IUpdatable 20: { 21: private List<NastyWord> pendingUpdates = new List<NastyWord>(); 22: private string pathToFile = @"path to your\App_Data\NastyWords.txt"; 23:   24: public NastyWordsDataSource() 25: { 26: UpdateFromSource(); 27: } 28:   29: private void UpdateFromSource() 30: { 31: var words = File.ReadAllLines(pathToFile); 32: NastyWords = (from w in words 33: select new NastyWord { Word = w }).AsQueryable(); 34: } 35:   36: public IQueryable<NastyWord> NastyWords { get; private set; } 37:   38: public void AddReferenceToCollection(object targetResource, string propertyName, object resourceToBeAdded) 39: { 40: throw new NotImplementedException(); 41: } 42:   43: public void ClearChanges() 44: { 45: pendingUpdates.Clear(); 46: } 47:   48: public object CreateResource(string containerName, string fullTypeName) 49: { 50: var nastyWord = new NastyWord(); 51: pendingUpdates.Add(nastyWord); 52: return nastyWord; 53: } 54:   55: public void DeleteResource(object targetResource) 56: { 57: throw new NotImplementedException(); 58: } 59:   60: public object GetResource(IQueryable query, string fullTypeName) 61: { 62: throw new NotImplementedException(); 63: } 64:   65: public object GetValue(object targetResource, string propertyName) 66: { 67: throw new NotImplementedException(); 68: } 69:   70: public void RemoveReferenceFromCollection(object targetResource, string propertyName, object resourceToBeRemoved) 71: { 72: throw new NotImplementedException(); 73: } 74:   75: public object ResetResource(object resource) 76: { 77: throw new NotImplementedException(); 78: } 79:   80: public object ResolveResource(object resource) 81: { 82: return resource; 83: } 84:   85: public void SaveChanges() 86: { 87: var intersect = (from w in pendingUpdates 88: select w.Word).Intersect(from n in NastyWords 89: select n.Word); 90:   91: if (intersect.Count() > 0) 92: throw new DataServiceException(500, "duplicate entry"); 93:   94: var lines = from w in pendingUpdates 95: select w.Word; 96:   97: File.AppendAllLines(pathToFile, 98: lines, 99: Encoding.UTF8); 100:   101: pendingUpdates.Clear(); 102:   103: UpdateFromSource(); 104: } 105:   106: public void SetReference(object targetResource, string propertyName, object propertyValue) 107: { 108: throw new NotImplementedException(); 109: } 110:   111: public void SetValue(object targetResource, string propertyName, object propertyValue) 112: { 113: targetResource.GetType().GetProperty(propertyName).SetValue(targetResource, propertyValue, null); 114: } 115: } 116:   117: public class NastyWords : DataService<NastyWordsDataSource> 118: { 119: // This method is called only once to initialize service-wide policies. 120: public static void InitializeService(DataServiceConfiguration config) 121: { 122: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead | EntitySetRights.WriteAppend); 123: config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 124: } 125: } 126: } Next time we’ll allow removing nasty words. Enjoy!

    Read the article

  • Class Mapping Error: 'T' must be a non-abstract type with a public parameterless constructor

    - by Amit Ranjan
    Hi, While mapping class i am getting error 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. Below is my SqlReaderBase Class public abstract class SqlReaderBase<T> : ConnectionProvider { #region Abstract Methods protected abstract string commandText { get; } protected abstract CommandType commandType { get; } protected abstract Collection<IDataParameter> GetParameters(IDbCommand command); **protected abstract MapperBase<T> GetMapper();** #endregion #region Non Abstract Methods /// <summary> /// Method to Execute Select Queries for Retrieveing List of Result /// </summary> /// <returns></returns> public Collection<T> ExecuteReader() { //Collection of Type on which Template is applied Collection<T> collection = new Collection<T>(); // initializing connection using (IDbConnection connection = GetConnection()) { try { // creates command for sql operations IDbCommand command = connection.CreateCommand(); // assign connection to command command.Connection = connection; // assign query command.CommandText = commandText; //state what type of query is used, text, table or Sp command.CommandType = commandType; // retrieves parameter from IDataParameter Collection and assigns it to command object foreach (IDataParameter param in GetParameters(command)) command.Parameters.Add(param); // Establishes connection with database server connection.Open(); // Since it is designed for executing Select statements that will return a list of results // so we will call command's execute reader method that return a Forward Only reader with // list of results inside. using (IDataReader reader = command.ExecuteReader()) { try { // Call to Mapper Class of the template to map the data to its // respective fields MapperBase<T> mapper = GetMapper(); collection = mapper.MapAll(reader); } catch (Exception ex) // catch exception { throw ex; // log errr } finally { reader.Close(); reader.Dispose(); } } } catch (Exception ex) { throw ex; } finally { connection.Close(); connection.Dispose(); } } return collection; } #endregion } What I am trying to do is , I am executine some command and filling my class dynamically. The class is given below: namespace FooZo.Core { public class Restaurant { #region Private Member Variables private int _restaurantId = 0; private string _email = string.Empty; private string _website = string.Empty; private string _name = string.Empty; private string _address = string.Empty; private string _phone = string.Empty; private bool _hasMenu = false; private string _menuImagePath = string.Empty; private int _cuisine = 0; private bool _hasBar = false; private bool _hasHomeDelivery = false; private bool _hasDineIn = false; private int _type = 0; private string _restaurantImagePath = string.Empty; private string _serviceAvailableTill = string.Empty; private string _serviceAvailableFrom = string.Empty; public string Name { get { return _name; } set { _name = value; } } public string Address { get { return _address; } set { _address = value; } } public int RestaurantId { get { return _restaurantId; } set { _restaurantId = value; } } public string Website { get { return _website; } set { _website = value; } } public string Email { get { return _email; } set { _email = value; } } public string Phone { get { return _phone; } set { _phone = value; } } public bool HasMenu { get { return _hasMenu; } set { _hasMenu = value; } } public string MenuImagePath { get { return _menuImagePath; } set { _menuImagePath = value; } } public string RestaurantImagePath { get { return _restaurantImagePath; } set { _restaurantImagePath = value; } } public int Type { get { return _type; } set { _type = value; } } public int Cuisine { get { return _cuisine; } set { _cuisine = value; } } public bool HasBar { get { return _hasBar; } set { _hasBar = value; } } public bool HasHomeDelivery { get { return _hasHomeDelivery; } set { _hasHomeDelivery = value; } } public bool HasDineIn { get { return _hasDineIn; } set { _hasDineIn = value; } } public string ServiceAvailableFrom { get { return _serviceAvailableFrom; } set { _serviceAvailableFrom = value; } } public string ServiceAvailableTill { get { return _serviceAvailableTill; } set { _serviceAvailableTill = value; } } #endregion public Restaurant() { } } } For filling my class properties dynamically i have another class called MapperBase Class with following methods: public abstract class MapperBase<T> where T : new() { protected T Map(IDataRecord record) { T instance = new T(); string fieldName; PropertyInfo[] properties = typeof(T).GetProperties(); for (int i = 0; i < record.FieldCount; i++) { fieldName = record.GetName(i); foreach (PropertyInfo property in properties) { if (property.Name == fieldName) { property.SetValue(instance, record[i], null); } } } return instance; } public Collection<T> MapAll(IDataReader reader) { Collection<T> collection = new Collection<T>(); while (reader.Read()) { collection.Add(Map(reader)); } return collection; } } There is another class which inherits the SqlreaderBaseClass called DefaultSearch. Code is below public class DefaultSearch: SqlReaderBase<Restaurant> { protected override string commandText { get { return "Select Name from vw_Restaurants"; } } protected override CommandType commandType { get { return CommandType.Text; } } protected override Collection<IDataParameter> GetParameters(IDbCommand command) { Collection<IDataParameter> parameters = new Collection<IDataParameter>(); parameters.Clear(); return parameters; } protected override MapperBase<Restaurant> GetMapper() { MapperBase<Restaurant> mapper = new RMapper(); return mapper; } } But whenever I tried to build , I am getting error 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. Even T here is Restaurant has a Parameterless Public constructor.

    Read the article

  • Why does select SCOPE_IDENTITY() return a decimal instead of an integer?

    - by Earlz
    So I have a table with an identity column as the primary key, so it is an integer. So, why does SCOPE_IDENTITY() always return a decimal value instead of an int to my C# application? This is really annoying since decimal values will not implicitly convert to integers in C#, which means I now have to rewrite a bunch of stuff and have a lot of helper methods because I use SQL Server and Postgres, which Postgres does return an integer for the equivalent function.. Why does SCOPE_IDENTITY() not just return a plain integer? Are there people out there that commonly use decimal/non-identity values for primary keys?

    Read the article

  • [Principles] Concrete Type or Interface for method return type?

    - by SDReyes
    In general terms, whats the better election for a method's return type: a concrete type or an interface? In most cases, I tend to use concrete types as the return type for methods. because I believe that an concrete type is more flexible for further use and exposes more functionality. The dark side of this: Coupling. The angelic one: A concrete type contains per-se the interface you would going to return initially, and extra functionality. What's your thumb's rule? Is there any programming principle for this? BONUS: This is an example of what I mean http://stackoverflow.com/questions/491375/readonlycollection-or-ienumerable-for-exposing-member-collections

    Read the article

  • Explicit return from a Ruby method - implementation hiding, reuse and optimisations.

    - by Chris McCauley
    Hi, Rather than allowing a Ruby method to blindly return the last statement evaluated, is there any advantage to returning nil explicitly? In terms of implementation hiding and reuse, it seems dangerous to blindly allow the last expression evaluated to be returned - isn't there a danger that a user will rely on this only to get a nasty surprise when the implementation is modified? Surely returning nil would be better unless an explicit return value was given. Following on, is there an optimisation that Ruby can make when the return is a simple type rather than a reference to a more complex object? Chris

    Read the article

  • Explicit return form a Ruby method - implementation hiding, reuse and optimisations.

    - by Chris McCauley
    Hi, Rather than allowing a Ruby method to blindly return the last statement evaluated, is there any advantage to returning nil explicitly? In terms of implementation hiding and reuse, it seems dangerous to blindly allow the last expression evaluated to be returned - isn't there a danger that a user will rely on this only to get a nasty surprise when the implementation is modified? Surely returning nil would be better unless an explicit return value was given. Following on, is there an optimisation that Ruby can make when the return is a simple type rather than a reference to a more complex object? Chris

    Read the article

  • filtering for multiple values on one column. All values must exist, else - return zero

    - by Andrew
    Hello All, I would like to filter one column in a table for couple values and show results only if all those values are there. If one or more is missing, then return zero results. example table +----+--------+----------+ | id | Fruit | Color | +----+--------+----------+ | 1 | apple | red | | 2 | mango | yellow | | 3 | banana | yellow | +----+--------+----------+ example "wrong" code: (this must return 3 rows) select Fruit FROM table WHERE Color = red AND Color = yellow but select Fruit FROM table WHERE Color = red AND Color = green must return 0 rows. (If i use select Fruit FROM table WHERE Color = red OR Color = green i get 1 row which is not what i need) I am using PHP with form where user checks different checkboxes that represent different values of the same column. So when he selects multiple checkboxes, all those values should be in the result set, otherwise no result should be given. Thank you, Andrew

    Read the article

  • When does a query/subquery return a NULL and when no value at all?

    - by AspOnMyNet
    a) If a query/subquery doesn’t find any matching rows, then it either returns NULL or no value at all, thus not even a NULL value. Based on what criteria does a query/subquery return a NULL and when doesn’t it return any results, not even a NULL value? b) I assume a scalar subquery will always return NULL, when no matching rows are found? I assume most-outer scalar query also returns NULL if no rows are found? c) SELECT FirstName, LastName, YEAR(BirthDate) FROM Persons WHERE YEAR(BirthDate) IN (SELECT YearReleased FROM Albums); If subquery finds no results, is then a WHERE clause of an outer query translated into WHERE YEAR(BirthDate) IN (null); ? If instead WHERE clause is translated into WHERE YEAR(BirthDate) IN(); then shouldn’t that be an error condition, since how can YEAR(BirthDate) value be compared to nothing? thanx

    Read the article

  • How do i return a StringWriter When I cant Clone it?

    - by acidzombie24
    My code looks like the below. Obviously i cant write 'ok' because the object has been disposed. I cant do return sw.Clone() bc clone doesnt exist. If i dont use a using then at any point between = new and return (like iterating and writing to the object as my example doesnt do) can have an exception and thus not disposing the object. Am i to define sw outside of a try block and check if its null then dispose in a catch block? That seems like a bit of excessive work. Is there a better way? is that the only way? static void func1() { using (var sw = func2()) { sw.WriteLine("Ok"); } } static StringWriter func2() { using (var sw = new StringWriter()) { return sw; } }

    Read the article

  • [C] this code, its work fine and return what i want, but its hangs before print it ??

    - by Rami Jarrar
    I make this program :: #include<stdio.h> char *raw_input(char *msg); main() { char *s; *s = *raw_input("Message Here Is: "); printf("Return Done.."); printf(s); } char *raw_input(char *msg){ char *d; printf("%s", msg); scanf("%s",&d); return d; } What this do is, it print my message and scan for input from the user, then print it,, but whats the problem in print the input from the user ??? Update:: I need the raw_input func. call be like this without any extra *s = *raw_input("Message Here"); I dont want to use this :: raw_input("Message Here Is: ", d); .... Just want to return the string that the user will enter .

    Read the article

  • Is it a good idea to return " const char * " from a function?

    - by AJ
    Now I have a function that has to return a string. I saw a particular implementation where he returns a const char * from the function. Something like this: const char * GetSomeString() { ........ return somestlstring.c_str(); } SomeOtherFoo () { const char * tmp = GetSomeString(); string s = tmp; } Now I felt there is something potentially wrong with this. Is my gut feel right? or Is this a perfectly safe code? Kindly give me ur suggestions. I have a feeling return const char * this way might result in havoc.. Thanks, Arjun

    Read the article

  • How to create a generic C free function .

    - by nomemory
    I have some C structures related to a 'list' data structure. They look like this. struct nmlist_element_s { void *data; struct nmlist_element_s *next; }; typedef struct nmlist_element_s nmlist_element; struct nmlist_s { void (*destructor)(void *data); int (*cmp)(const void *e1, const void *e2); unsigned int size; nmlist_element *head; nmlist_element *tail; }; typedef struct nmlist_s nmlist; This way I can have different data types being hold in "nmlist_element-data" . The "constructor" (in terms of OOP) has the following signature: nmlist *nmlist_alloc(void (*destructor)(void *data)); Where "destructor" is specific function that de-allocated "data" (being hold by the nmlist_element). If I want to have a list containing integers as data, my "destructor" would like this: void int_destructor(void *data) { free((int*)data); } Still i find it rather "unfriendly" for me to write a destructor functions for every simple primitive data type. So is there a trick to write something like this ? (for primitives): void "x"_destructor(void *data, "x") { free(("x" *)data); } PS: I am not a macro fan myself, and in my short experience regarding C, i don't use them, unless necessary.

    Read the article

  • Oracle aggregate function to return a random value for a group?

    - by tpdi
    The standard SQL aggregate function max() will return the highest value in a group; min() will return the lowest. Is there an aggregate function in Oracle to return a random value from a group? Or some technique to achieve this? E.g., given the table foo: group_id value 1 1 1 5 1 9 2 2 2 4 2 8 The SQL query select group_id, max(value), min(value), some_aggregate_random_func(value) from foo group by group_id; might produce: group_id max(value), min(value), some_aggregate_random_func(value) 1 9 1 1 2 8 2 4 with, obviously, the last column being any random value in that group.

    Read the article

< Previous Page | 65 66 67 68 69 70 71 72 73 74 75 76  | Next Page >