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• Oracle Delivers Latest Release of Oracle Enterprise Manager 12c

  - by Scott McNeil

  Richer Service Catalog for Database and Middleware as a Service; Enhanced Database and Middleware Management Help Drive Enterprise-Scale Private Cloud Adoption News Summary IT organizations are adopting private clouds as a stepping-stone to business-driven, self-service IT. Successful implementations hinge on the ability to efficiently deploy and manage cloud services at enterprise scale. Having a complete cloud management solution integrated with an enterprise-class technology stack is a fundamental requirement for IT. Oracle Enterprise Manager 12c Release 4 meets that requirement by helping businesses become more agile and responsive, while reducing cost, complexity, and risk. News Facts Oracle Enterprise Manager 12c Release 4, available today, lets organizations rapidly adopt Oracle-based, enterprise-scale private clouds. New capabilities provide advanced technology stack management, secure database administration, and enterprise service governance, enabling Oracle customers and partners to maximize database and application performance and drive innovation using self-service IT platforms. The enhancements have been driven by customers and the growing Oracle Enterprise Manager Ecosystem, comprised of more than 750 Oracle PartnerNetwork (OPN) Specialized partners. Oracle and its partners and customers have built over 140 plug-ins and connectors for Oracle Enterprise Manager. Watch the video highlights. Automation for Broader Cloud Services Oracle Enterprise Manager 12c Release 4 allows for a rapid enterprise-wide adoption of database, middleware and infrastructure services in the private cloud, driven by an enhanced API-enabled service catalog. The release features “push button” style provisioning of complete environments such as SOA and Oracle Active Data Guard, and fast data cloning that enables rapid deployment and testing of enterprise applications. Out-of-the-box capabilities to detect data and configuration vulnerabilities provide enhanced cloud service governance along with greater operational control through a flexible and extensible showback mechanism. Enhanced Database Management A new performance warehouse enables predictive database diagnostics and trend analysis and helps identify database problems before they occur. New enterprise data-governance capabilities enhance security by helping systematically discover and protect sensitive data. Step-by-step orchestration of upgrades with the ability to rollback changes enables faster adoption of Oracle Database 12c. Expanded Fusion Middleware Management A new consolidated view of Oracle Fusion Middleware 12c deployments with a guided management capability lets administrators apply best management practices to diverse middleware environments and identify performance issues quickly. A Java VM Diagnostics as a Service feature allows governed access to diagnostics data for IT workers across multiple disciplines for accelerated DevOps resolutions of defects and performance optimization. New automated provisioning for SOA lets middleware administrators perform mass SOA provisioning with ease. Superior Enterprise-Grade Management Private roles and preferred credentials have been added to Oracle Enterprise Manager to provide additional fine-grained security for organizations with complex access control requirements. A new security console provides a single point of control for managing the security of Oracle Enterprise Manager environments. Support for the latest industry standard SNMP v3 protocol, including encryption, enables more secure heterogeneous management. “Smart monitoring” adapts to observed environmental changes and adds self-management capabilities to help Oracle Enterprise Manager run at peak performance, while demanding less IT supervision. Supporting Quotes “Lawrence Livermore National Laboratory has a strong tradition of technology breakthroughs and leadership. As a member of Oracle’s Customer Advisory Board for Oracle Enterprise Manager, we have consistently provided feedback and guidance in the areas of enterprise-scale cloud, self-diagnosability, and secure administration for the product,” said Tim Frazier, CIO, NIF and Photon Sciences, Lawrence Livermore National Laboratory. “We intend to take advantage of the Release 4 features that support enterprise-scale availability and fine-grained security capabilities for private cloud deployments.” “IDC's most recent CloudTrack survey shows that most enterprises plan to adopt hybrid cloud architectures over the next three years,” said Mary Johnston Turner, Research Vice President, Enterprise System Management Software, IDC. “These organizations plan to deploy a wide range of workloads into cloud environments including mission critical database and middleware services that require high levels of fault tolerance and disaster recovery. Such capabilities were traditionally custom configured for each application but cloud offers the possibility to incorporate such properties within the service definition, enabling organizations to adopt cloud without compromise. With the latest release of Oracle Enterprise Manager 12c, Oracle is providing customers with an out-of-the-box experience for delivering highly-resilient cloud services for databases and applications.” “Since its inception, Oracle has been leading the way in innovative, scalable and high performance solutions for the enterprise. With this release of Oracle Enterprise Manager, we are extending this leadership by providing enterprise-scale capabilities for planning, delivering, and managing private clouds. We call this ‘zero-to-cloud – accelerated.’ These enhancements help our customers to expedite their adoption of cloud computing and prepares them for the next generation of self-service IT,” said Prakash Ramamurthy, senior vice president of Systems and Cloud Management at Oracle. Supporting Resources Oracle Enterprise Manager 12c Video: Cerner Delivers High Performance Private Cloud Video: BIAS Achieves Outstanding Results with Private Cloud Press Release Stay Connected: Twitter | Facebook | YouTube | Linkedin | Newsletter Download the Oracle Enterprise Manager 12c Mobile app

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• 2D OBB collision detection, resolving collisions?

  - by Milo

  I currently use OBBs and I have a vehicle that is a rigid body and some buildings. Here is my update() private void update() { camera.setPosition((vehicle.getPosition().x * camera.getScale()) - ((getWidth() ) / 2.0f), (vehicle.getPosition().y * camera.getScale()) - ((getHeight() ) / 2.0f)); //camera.move(input.getAnalogStick().getStickValueX() * 15.0f, input.getAnalogStick().getStickValueY() * 15.0f); if(input.isPressed(ControlButton.BUTTON_GAS)) { vehicle.setThrottle(1.0f, false); } if(input.isPressed(ControlButton.BUTTON_BRAKE)) { vehicle.setBrakes(1.0f); } vehicle.setSteering(input.getAnalogStick().getStickValueX()); vehicle.update(16.6666f / 1000.0f); ArrayList<Building> buildings = city.getBuildings(); for(Building b : buildings) { if(vehicle.getRect().overlaps(b.getRect())) { vehicle.update(-17.0f / 1000.0f); break; } } } The collision detection works well. What doesn't is how they are dealt with. My goal is simple. If the vehicle hits a building, it should stop, and never go into the building. When I apply negative torque to reverse the car should not feel buggy and move away from the building. I don't want this to look buggy. This is my rigid body class: class RigidBody extends Entity { //linear private Vector2D velocity = new Vector2D(); private Vector2D forces = new Vector2D(); private float mass; //angular private float angularVelocity; private float torque; private float inertia; //graphical private Vector2D halfSize = new Vector2D(); private Bitmap image; public RigidBody() { //set these defaults so we don't get divide by zeros mass = 1.0f; inertia = 1.0f; } //intialize out parameters public void initialize(Vector2D halfSize, float mass, Bitmap bitmap) { //store physical parameters this.halfSize = halfSize; this.mass = mass; image = bitmap; inertia = (1.0f / 20.0f) * (halfSize.x * halfSize.x) * (halfSize.y * halfSize.y) * mass; RectF rect = new RectF(); float scalar = 10.0f; rect.left = (int)-halfSize.x * scalar; rect.top = (int)-halfSize.y * scalar; rect.right = rect.left + (int)(halfSize.x * 2.0f * scalar); rect.bottom = rect.top + (int)(halfSize.y * 2.0f * scalar); setRect(rect); } public void setLocation(Vector2D position, float angle) { getRect().set(position, getWidth(), getHeight(), angle); } public Vector2D getPosition() { return getRect().getCenter(); } @Override public void update(float timeStep) { //integrate physics //linear Vector2D acceleration = Vector2D.scalarDivide(forces, mass); velocity = Vector2D.add(velocity, Vector2D.scalarMultiply(acceleration, timeStep)); Vector2D c = getRect().getCenter(); c = Vector2D.add(getRect().getCenter(), Vector2D.scalarMultiply(velocity , timeStep)); setCenter(c.x, c.y); forces = new Vector2D(0,0); //clear forces //angular float angAcc = torque / inertia; angularVelocity += angAcc * timeStep; setAngle(getAngle() + angularVelocity * timeStep); torque = 0; //clear torque } //take a relative Vector2D and make it a world Vector2D public Vector2D relativeToWorld(Vector2D relative) { Matrix mat = new Matrix(); float[] Vector2Ds = new float[2]; Vector2Ds[0] = relative.x; Vector2Ds[1] = relative.y; mat.postRotate(JMath.radToDeg(getAngle())); mat.mapVectors(Vector2Ds); return new Vector2D(Vector2Ds[0], Vector2Ds[1]); } //take a world Vector2D and make it a relative Vector2D public Vector2D worldToRelative(Vector2D world) { Matrix mat = new Matrix(); float[] Vectors = new float[2]; Vectors[0] = world.x; Vectors[1] = world.y; mat.postRotate(JMath.radToDeg(-getAngle())); mat.mapVectors(Vectors); return new Vector2D(Vectors[0], Vectors[1]); } //velocity of a point on body public Vector2D pointVelocity(Vector2D worldOffset) { Vector2D tangent = new Vector2D(-worldOffset.y, worldOffset.x); return Vector2D.add( Vector2D.scalarMultiply(tangent, angularVelocity) , velocity); } public void applyForce(Vector2D worldForce, Vector2D worldOffset) { //add linear force forces = Vector2D.add(forces ,worldForce); //add associated torque torque += Vector2D.cross(worldOffset, worldForce); } @Override public void draw( GraphicsContext c) { c.drawRotatedScaledBitmap(image, getPosition().x, getPosition().y, getWidth(), getHeight(), getAngle()); } } Essentially, when any rigid body hits a building it should exhibit the same behavior. How is collision solving usually done? Thanks

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• Multithreading in lwjgl getting rid of sleep.

  - by pangaea

  I'm trying to use multithreading in my game. However, I can't seem to get rid of the sleep. If I don't it's a blank screen, as there is no time for the computer to actually render the triangleMob as it can't access getArrayList(), in my main class I have a TriangleMob arraylist. If I delay it, then it can access the previousMob and it renders. If I don't, then it's blank screen. Can I get rid of the delay? Also, is this a bad way to multithread? Surely, this should be fast. I need multithreading so can you please not suggest not using it. public class TriangleMob extends Thread implements Runnable { private static int count=0; private int objectDisplayList; private static ArrayList<TriangleMob> previousMob = new ArrayList<TriangleMob>(); private static ArrayList<TriangleMob> currentMob = new ArrayList<TriangleMob>(); private static ArrayList<TriangleMob> laterMob = new ArrayList<TriangleMob>(); private Vector3f position = new Vector3f(0f,0f,0f); private Vector3f movement = new Vector3f(0f,0f,0f); public TriangleMob() { // Create the display list CreateDisplayList(); count++; } public TriangleMob(Vector3f position) { // Create the display list CreateDisplayList(); this.position = position; count++; } private void CreateDisplayList() { objectDisplayList = glGenLists(1); glNewList(objectDisplayList, GL_COMPILE); { double topPoint = 0.75; glBegin(GL_TRIANGLES); glColor4f(1, 1, 0, 1f); glVertex3d(0, topPoint, -5); glColor4f(0, 0, 1, 1f); glVertex3d(-1, -0.75, -4); glColor4f(0, 0, 1, 1f); glVertex3d(1, -.75, -4); glColor4f(1, 1, 0, 1f); glVertex3d(0, topPoint, -5); glColor4f(0, 0, 1, 1f); glVertex3d(1, -0.75, -4); glColor4f(0, 0, 1, 1f); glVertex3d(1, -0.75, -6); glColor4f(1, 1, 0, 1f); glVertex3d(0, topPoint, -5); glColor4f(0, 0, 1, 1f); glVertex3d(1, -0.75, -6); glColor4f(0, 0, 1, 1f); glVertex3d(-1, -.75, -6); glColor4f(1, 1, 0, 1f); glVertex3d(0, topPoint, -5); glColor4f(0, 0, 1, 1f); glVertex3d(-1, -0.75, -6); glColor4f(0, 0, 1, 1f); glVertex3d(-1, -.75, -4); glEnd(); glColor4f(1, 1, 1, 1); } glEndList(); } public static int getCount() { return count; } public Vector3f getMovement() { return movement; } public Vector3f getPosition() { return position; } public synchronized int getObjectList() { return objectDisplayList; } public synchronized static ArrayList<TriangleMob> getArrayList(){ if(previousMob != null) { return previousMob; } previousMob.add(new TriangleMob()); return previousMob; } public synchronized void move(Vector3f movement) { // If you want to move in all 3 axis position.x += movement.x; position.y += movement.y; position.z += movement.z; } public synchronized void render() { glPushMatrix(); glTranslatef(-position.x, -position.y, -position.z); glCallList(objectDisplayList); glPopMatrix(); } public synchronized static void setTriangleMob(ArrayList<TriangleMob> triangleMobSet) { laterMob = triangleMobSet; } private synchronized void setPreTriangleMob(ArrayList<TriangleMob> currentMob2) { previousMob = currentMob2; } public void run(){ while(true) { if(laterMob == null) { currentMob = laterMob; System.out.println("Copying"); } for(int i=0; i<currentMob.size(); i++) { currentMob.get(i).move(new Vector3f(0.1f,0.01f,0.01f)); } setPreTriangleMob(currentMob); try { sleep(1L); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }

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• Encrypt images before uploading to Dropbox [migrated]

  - by Cherry

  I want to encrypt a file first before the file will be uploaded to the dropbox. So i have implement the encryption inside the uploading of the codes. However, there is an error after i integrate the codes together. Where did my mistake go wrong? Error at putFileOverwriteRequest and it says The method putFileOverwriteRequest(String, InputStream, long, ProgressListener) in the type DropboxAPI is not applicable for the arguments (String, FileOutputStream, long, new ProgressListener(){}) Another problem is that this FileOutputStream fis = new FileOutputStream(new File("dont know what to put in this field")); i do not know where to put the file so that after i read the file, it will call the path and then upload to the Dropbox. Anyone is kind to help me in this? As time is running out for me and i still cant solve the problem. Thank you in advance. The full code is as below. public class UploadPicture extends AsyncTask<Void, Long, Boolean> { private DropboxAPI<?> mApi; private String mPath; private File mFile; private long mFileLen; private UploadRequest mRequest; private Context mContext; private final ProgressDialog mDialog; private String mErrorMsg; public UploadPicture(Context context, DropboxAPI<?> api, String dropboxPath, File file) { // We set the context this way so we don't accidentally leak activities mContext = context.getApplicationContext(); mFileLen = file.length(); mApi = api; mPath = dropboxPath; mFile = file; mDialog = new ProgressDialog(context); mDialog.setMax(100); mDialog.setMessage("Uploading " + file.getName()); mDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); mDialog.setProgress(0); mDialog.setButton("Cancel", new OnClickListener() { public void onClick(DialogInterface dialog, int which) { // This will cancel the putFile operation mRequest.abort(); } }); mDialog.show(); } @Override protected Boolean doInBackground(Void... params) { try { KeyGenerator keygen = KeyGenerator.getInstance("DES"); SecretKey key = keygen.generateKey(); //generate key //encrypt file here first byte[] plainData; byte[] encryptedData; Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key); //File f = new File(mFile); //read file FileInputStream in = new FileInputStream(mFile); //obtains input bytes from a file plainData = new byte[(int)mFile.length()]; in.read(plainData); //Read bytes of data into an array of bytes encryptedData = cipher.doFinal(plainData); //encrypt data FileOutputStream fis = new FileOutputStream(new File("dont know what to put in this field")); //upload to a path first then call the path so that it can be uploaded up to the dropbox //save encrypted file to dropbox // By creating a request, we get a handle to the putFile operation, // so we can cancel it later if we want to //FileInputStream fis = new FileInputStream(mFile); String path = mPath + mFile.getName(); mRequest = mApi.putFileOverwriteRequest(path, fis, mFile.length(), new ProgressListener() { @Override public long progressInterval() { // Update the progress bar every half-second or so return 500; } @Override public void onProgress(long bytes, long total) { publishProgress(bytes); } }); if (mRequest != null) { mRequest.upload(); return true; } } catch (DropboxUnlinkedException e) { // This session wasn't authenticated properly or user unlinked mErrorMsg = "This app wasn't authenticated properly."; } catch (DropboxFileSizeException e) { // File size too big to upload via the API mErrorMsg = "This file is too big to upload"; } catch (DropboxPartialFileException e) { // We canceled the operation mErrorMsg = "Upload canceled"; } catch (DropboxServerException e) { // Server-side exception. These are examples of what could happen, // but we don't do anything special with them here. if (e.error == DropboxServerException._401_UNAUTHORIZED) { // Unauthorized, so we should unlink them. You may want to // automatically log the user out in this case. } else if (e.error == DropboxServerException._403_FORBIDDEN) { // Not allowed to access this } else if (e.error == DropboxServerException._404_NOT_FOUND) { // path not found (or if it was the thumbnail, can't be // thumbnailed) } else if (e.error == DropboxServerException._507_INSUFFICIENT_STORAGE) { // user is over quota } else { // Something else } // This gets the Dropbox error, translated into the user's language mErrorMsg = e.body.userError; if (mErrorMsg == null) { mErrorMsg = e.body.error; } } catch (DropboxIOException e) { // Happens all the time, probably want to retry automatically. mErrorMsg = "Network error. Try again."; } catch (DropboxParseException e) { // Probably due to Dropbox server restarting, should retry mErrorMsg = "Dropbox error. Try again."; } catch (DropboxException e) { // Unknown error mErrorMsg = "Unknown error. Try again."; } catch (FileNotFoundException e) { } return false; } @Override protected void onProgressUpdate(Long... progress) { int percent = (int)(100.0*(double)progress[0]/mFileLen + 0.5); mDialog.setProgress(percent); } @Override protected void onPostExecute(Boolean result) { mDialog.dismiss(); if (result) { showToast("Image successfully uploaded"); } else { showToast(mErrorMsg); } } private void showToast(String msg) { Toast error = Toast.makeText(mContext, msg, Toast.LENGTH_LONG); error.show(); } }

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• SChannel "cannot find certificate in either LocalMachine or CurrentUser store"

  - by Chris J

  We have an in-house application that requires the use of client SSL certificates to authenticate with a remote server (not under our control). This has worked without problems before but on deploying to a new server, we're having problems getting Windows 2008 to use the certificate. The certificate exists as a .pfx file that contains a private key. The same certificate exists in the LocalMachine store, again with its private key. We've ensured the one in the LocalMachine store is correct by creating a website in IIS against that certificate, so we're happy that the certificate, certificate chain, and private key is valid. The PFX has been created by exporting from the Certificates MMC snap-in. The issue is that we get the following in the system diagnostic logs that suggests it can't find the private key: System.Net Information: 0 : [5988] SecureChannel#23264094 – Locating the private key for the certificate: [Subject] CN=internal-server.company.com, OU=Servers, OU=Devices, O=org [Issuer] CN=SubCA02, OU=CA, o=org [Serial Number] 407ABCDE [Not Before] 31/10/2013 11:08:48 AM [Not After] 31/10/2016 11:08:48 AM [Thumbprint] 4354A34F6004F019E60F055979A47E50F62D1504 . System.Net Information: 0 : [5988] SecureChannel#23264094 – Cannot find the certificate in either the LocalMachine store or the CurrentUser store. I've validated the thumbprint, issuer and serial number listed in the log with the certificate in the LocalMachine store and these marry up. From what I can tell with much searching, this appears to be a permissions issue. The user the application is running as has been granted access to the private key (Personal Certificates - right click on the certificate - all tasks - Manage Private Keys), so I'm now at a loss as to which permission(s) it may be that is causing the issue.

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• SPP Socket createRfcommSocketToServiceRecord will not connect

  - by philDev

  Hello, I want to use Android 2.1 to connect to an external Bluetooth device, wich is offering an SPP port to me. In this case it is an external GPS unit. When I'm trying to connect I can't connect an established socket while being in the "client" mode. Then if I try to set up a socket (being in the server role), to RECEIVE text from my PC everything works just fine. The Computer can connect as the client to the Socket on the Phone via SPP using the SSP UUID or some random UUID. So the Problem is not that I'm using the wrong UUID. But the other way around (e.g. calling connect on the established client socket) createRfcommSocketToServiceRecord(UUID uuid)) just doesn't work. Sadly I don't have the time to inspect the problem further. It would be greate If somebody could point me the right way. In the following part of the Logfile has to be the Problem. Greets PhilDev P.S. I'm going to be present during the Office hours. Here the log file: 03-21 03:10:52.020: DEBUG/BluetoothSocket.cpp(4643): initSocketFromFdNative 03-21 03:10:52.025: DEBUG/BluetoothSocket(4643): connect 03-21 03:10:52.025: DEBUG/BluetoothSocket(4643): doSdp 03-21 03:10:52.050: DEBUG/ADAPTER(2132): create_device(01:00:00:7F:B5:B3) 03-21 03:10:52.050: DEBUG/ADAPTER(2132): adapter_create_device(01:00:00:7F:B5:B3) 03-21 03:10:52.055: DEBUG/DEVICE(2132): Creating device [address = 01:00:00:7F:B5:B3] /org/bluez/2132/hci0/dev_01_00_00_7F_B5_B3 [name = ] 03-21 03:10:52.055: DEBUG/DEVICE(2132): btd_device_ref(0x10c18): ref=1 03-21 03:10:52.065: INFO/BluetoothEventLoop.cpp(1914): event_filter: Received signal org.bluez.Adapter:DeviceCreated from /org/bluez/2132/hci0 03-21 03:10:52.065: INFO/BluetoothService.cpp(1914): ... Object Path = /org/bluez/2132/hci0/dev_01_00_00_7F_B5_B3 03-21 03:10:52.065: INFO/BluetoothService.cpp(1914): ... Pattern = 00001101-0000-1000-8000-00805f9b34fb, strlen = 36 03-21 03:10:52.070: DEBUG/DEVICE(2132): *************DiscoverServices******** 03-21 03:10:52.070: INFO/DTUN_HCID(2132): dtun_client_get_remote_svc_channel: starting discovery on (uuid16=0x0011) 03-21 03:10:52.070: INFO/DTUN_HCID(2132): bdaddr=01:00:00:7F:B5:B3 03-21 03:10:52.070: INFO/DTUN_CLNT(2132): Client calling DTUN_METHOD_DM_GET_REMOTE_SERVICE_CHANNEL (id 4) 03-21 03:10:52.070: INFO/(2106): DTUN_ReceiveCtrlMsg: [DTUN] Received message [BTLIF_DTUN_METHOD_CALL] 4354 03-21 03:10:52.070: INFO/(2106): handle_method_call: handle_method_call :: received DTUN_METHOD_DM_GET_REMOTE_SERVICE_CHANNEL (id 4), len 134 03-21 03:10:52.075: ERROR/BTLD(2106): ****************search UUID = 1101*********** 03-21 03:10:52.075: INFO//system/bin/btld(2103): btapp_dm_GetRemoteServiceChannel() 03-21 03:10:52.120: DEBUG/BluetoothService(1914): updateDeviceServiceChannelCache(01:00:00:7F:B5:B3) 03-21 03:10:52.120: DEBUG/BluetoothEventLoop(1914): ClassValue: null for remote device: 01:00:00:7F:B5:B3 is null 03-21 03:10:52.120: INFO/BluetoothEventLoop.cpp(1914): event_filter: Received signal org.bluez.Adapter:PropertyChanged from /org/bluez/2132/hci0 03-21 03:10:52.305: WARN/BTLD(2106): bta_dm_check_av:0 03-21 03:10:56.395: DEBUG/WifiService(1914): ACTION_BATTERY_CHANGED pluggedType: 2 03-21 03:10:57.440: WARN/BTLD(2106): SDP - Rcvd conn cnf with error: 0x4 CID 0x43 03-21 03:10:57.440: INFO/BTL-IFS(2106): send_ctrl_msg: [BTL_IFS CTRL] send BTLIF_DTUN_SIGNAL_EVT (CTRL) 13 pbytes (hdl 10) 03-21 03:10:57.445: INFO/DTUN_CLNT(2132): dtun-rx signal [DTUN_SIG_DM_RMT_SERVICE_CHANNEL] (id 42) len 15 03-21 03:10:57.445: INFO/DTUN_HCID(2132): dtun_dm_sig_rmt_service_channel: success=1, service=00000000 03-21 03:10:57.445: ERROR/DTUN_HCID(2132): discovery unsuccessful! package de.phil_dev.android.BT; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.UUID; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothClass; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothServerSocket; import android.bluetooth.BluetoothSocket; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.widget.Toast; public class ThinBTClient extends Activity { private static final String TAG = "THINBTCLIENT"; private static final boolean D = true; private BluetoothAdapter mBluetoothAdapter = null; private BluetoothSocket btSocket = null; private BufferedInputStream inStream = null; private BluetoothServerSocket myServerSocket; private ConnectThread myConnection; private ServerThread myServer; // Well known SPP UUID (will *probably* map to // RFCOMM channel 1 (default) if not in use); // see comments in onResume(). private static final UUID MY_UUID = UUID .fromString("00001101-0000-1000-8000-00805F9B34FB"); // .fromString("94f39d29-7d6d-437d-973b-fba39e49d4ee"); // ==> hardcode your slaves MAC address here <== // PC // private static String address = "00:09:DD:50:86:A0"; // GPS private static String address = "00:0B:0D:8E:D4:33"; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); if (D) Log.e(TAG, "+++ ON CREATE +++"); mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter == null) { Toast.makeText(this, "Bluetooth is not available.", Toast.LENGTH_LONG).show(); finish(); return; } if (!mBluetoothAdapter.isEnabled()) { Toast.makeText(this, "Please enable your BT and re-run this program.", Toast.LENGTH_LONG).show(); finish(); return; } if (D) Log.e(TAG, "+++ DONE IN ON CREATE, GOT LOCAL BT ADAPTER +++"); } @Override public void onStart() { super.onStart(); if (D) Log.e(TAG, "++ ON START ++"); } @Override public void onResume() { super.onResume(); if (D) { Log.e(TAG, "+ ON RESUME +"); Log.e(TAG, "+ ABOUT TO ATTEMPT CLIENT CONNECT +"); } // Make the phone discoverable // When this returns, it will 'know' about the server, // via it's MAC address. // mBluetoothAdapter.startDiscovery(); BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address); Log.e(TAG, device.getName() + " connected"); // myServer = new ServerThread(); // myServer.start(); myConnection = new ConnectThread(device); myConnection.start(); } @Override public void onPause() { super.onPause(); if (D) Log.e(TAG, "- ON PAUSE -"); try { btSocket.close(); } catch (IOException e2) { Log.e(TAG, "ON PAUSE: Unable to close socket.", e2); } } @Override public void onStop() { super.onStop(); if (D) Log.e(TAG, "-- ON STOP --"); } @Override public void onDestroy() { super.onDestroy(); if (D) Log.e(TAG, "--- ON DESTROY ---"); } private class ServerThread extends Thread { private final BluetoothServerSocket myServSocket; public ServerThread() { BluetoothServerSocket tmp = null; // create listening socket try { tmp = mBluetoothAdapter .listenUsingRfcommWithServiceRecord( "myServer", MY_UUID); } catch (IOException e) { Log.e(TAG, "Server establishing failed"); } myServSocket = tmp; } public void run() { Log.e(TAG, "Beginn waiting for connection"); BluetoothSocket connectSocket = null; InputStream inStream = null; byte[] buffer = new byte[1024]; int bytes; while (true) { try { connectSocket = myServSocket.accept(); } catch (IOException e) { Log.e(TAG, "Connection failed"); break; } Log.e(TAG, "ALL THE WAY AROUND"); try { connectSocket = connectSocket.getRemoteDevice() .createRfcommSocketToServiceRecord(MY_UUID); connectSocket.connect(); } catch (IOException e1) { Log.e(TAG, "DIDNT WORK"); } // handle Connection try { inStream = connectSocket.getInputStream(); while (true) { try { bytes = inStream.read(buffer); Log.e(TAG, "Received: " + buffer.toString()); } catch (IOException e3) { Log.e(TAG, "disconnected"); break; } } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); break; } } } void cancel() { } } private class ConnectThread extends Thread { private final BluetoothSocket mySocket; private final BluetoothDevice myDevice; public ConnectThread(BluetoothDevice device) { myDevice = device; BluetoothSocket tmp = null; try { tmp = device.createRfcommSocketToServiceRecord(MY_UUID); } catch (IOException e) { Log.e(TAG, "CONNECTION IN THREAD DIDNT WORK"); } mySocket = tmp; } public void run() { Log.e(TAG, "STARTING TO CONNECT THE SOCKET"); setName("My Connection Thread"); InputStream inStream = null; boolean run = false; //mBluetoothAdapter.cancelDiscovery(); try { mySocket.connect(); run = true; } catch (IOException e) { run = false; Log.e(TAG, this.getName() + ": CONN DIDNT WORK, Try closing socket"); try { mySocket.close(); } catch (IOException e1) { Log.e(TAG, this.getName() + ": COULD CLOSE SOCKET", e1); this.destroy(); } } synchronized (ThinBTClient.this) { myConnection = null; } byte[] buffer = new byte[1024]; int bytes; // handle Connection try { inStream = mySocket.getInputStream(); while (run) { try { bytes = inStream.read(buffer); Log.e(TAG, "Received: " + buffer.toString()); } catch (IOException e3) { Log.e(TAG, "disconnected"); } } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } // starting connected thread (handling there in and output } public void cancel() { try { mySocket.close(); } catch (IOException e) { Log.e(TAG, this.getName() + " SOCKET NOT CLOSED"); } } } }

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• Problem to display 3D google map.

  - by nemade-vipin

  hello friends, I have implemented one Flex application in which I want to display 3D google map.In which I am getting the error the NUll object reference during map display. Here is my code:- import com.google.maps.controls.MapTypeControl; import adobe.utils.XMLUI; import mx.rpc.events.FaultEvent; import mx.controls.Alert; import generated.webservices.*; import mx.collections.ArrayCollection; import mx.controls.*; import generated.webservices.*; import com.google.maps.LatLng; import com.google.maps.Map3D; import com.google.maps.MapEvent; import com.google.maps.MapMouseEvent; import com.google.maps.services.GeocodingEvent; import com.google.maps.services.ClientGeocoder; import com.google.maps.overlays.Marker; import com.google.maps.InfoWindowOptions; import com.google.maps.MapOptions; import com.google.maps.MapType; import com.google.maps.View; import com.google.maps.controls.NavigationControl; import com.google.maps.geom.Attitude; import mx.controls.Alert; [Bindable] private var childName:ArrayCollection; [Bindable] private var childId:ArrayCollection; private var photoFeed:ArrayCollection; private var trackinginfochild:TrackingInfo; private var arrayOfchild:Array; private var newEntry:GetSBTSMobileAuthentication; private var trackinginfo:GetSBTSTrackingInfo; private var childObj:Child; private var UserId:int; private var lat:int; private var long:int; private var latlong:LatLng; public var user:SBTSWebService; public function authentication():void { // Instantiate a new Entry object. user = new SBTSWebService(); if(user!=null) { user.addSBTSWebServiceFaultEventListener(handleFaults); user.addgetSBTSMobileAuthenticationEventListener(authenticationResult); newEntry = new GetSBTSMobileAuthentication(); if(newEntry!=null) { newEntry.mobile=mobileno.text; newEntry.password=password.text; user.getSBTSMobileAuthentication(newEntry); } } } public function handleFaults(event:FaultEvent):void { Alert.show("A fault occured contacting the server. Fault message is: " + event.fault.faultString); } public function authenticationResult(event:GetSBTSMobileAuthenticationResultEvent):void { if(event.result != null && event.result._return>0) { if(event.result._return > 0) { UserId = event.result._return; loginform.enabled = false; getChildList(UserId); viewstack2.selectedIndex=1; } else { Alert.show("Authentication fail"); } } } public function getChildList(userId:int):void { var childEntry:GetSBTSMobileChildrenInfo = new GetSBTSMobileChildrenInfo(); childEntry.UserId = userId; user.addgetSBTSMobileChildrenInfoEventListener(sbtsChildrenInfoResult); user.getSBTSMobileChildrenInfo(childEntry); } public function sbtsChildrenInfoResult(event:GetSBTSMobileChildrenInfoResultEvent):void { if( event.result._return!=null) { arrayOfchild = event.result._return as Array; photoFeed = new ArrayCollection(arrayOfchild); childName = new ArrayCollection(); for( var count:int=0;count<photoFeed.length;count++) { childObj = photoFeed.getItemAt(count,0) as Child; childName.addItem(childObj.strName); } } } private function trackingInfo():void { for( var count:int=0;count user.getSBTSTrackingInfo(trackinginfo); } } } } private function getTrackingInfo(event:GetSBTSTrackingInfoResultEvent):void { if(event.result._return != null) { trackinginfochild = event.result._return as TrackingInfo; lat = trackinginfochild.dblLatitude; long = trackinginfochild.dblLongitude; latlong = new LatLng(lat,long); } } private function onMapPreinitialize(event:MapEvent):void { var myMapOptions:MapOptions = new MapOptions(); myMapOptions.zoom = 12; myMapOptions.center = latlong; myMapOptions.mapType = MapType.NORMAL_MAP_TYPE; myMapOptions.viewMode = View.VIEWMODE_PERSPECTIVE; myMapOptions.attitude = new Attitude(20,30,0); buslocation.setInitOptions(myMapOptions); buspath.setInitOptions(myMapOptions); } private function onMapReady(event:MapEvent):void { this.buslocation.addControl(new NavigationControl()); this.buslocation.addControl( new MapTypeControl()); } ]]> <mx:Move id="hideEffect" yTo="-500" /> <mx:Move id="showEffect" xFrom="500"/> <mx:Panel width="100%" height="100%" headerColors="[#000000,#FFFFFF]" hideEffect="{hideEffect}" showEffect="{showEffect}"> <mx:TabNavigator id="viewstack2" selectedIndex="0" creationPolicy="all" width="100%" height="100%"> <mx:Form label="Login Form" id="loginform" hideEffect="{hideEffect}" showEffect="{showEffect}"> <mx:FormItem label="Mobile NO:" creationPolicy="all"> <mx:TextInput id="mobileno"/> </mx:FormItem> <mx:FormItem label="Password:" creationPolicy="all"> <mx:TextInput displayAsPassword="true" id="password" /> </mx:FormItem> <mx:FormItem> <mx:Button label="Login" click="authentication()"/> </mx:FormItem> </mx:Form> <mx:Form label="Child List" id="childForm" hideEffect="{hideEffect}" showEffect="{showEffect}"> <mx:Label width="100%" color="blue" text="Select Child."/> <mx:RadioButtonGroup id="radioGroup" itemClick="trackingInfo()"/> <mx:Repeater id="fieldRepeater" dataProvider="{childName}"> <mx:RadioButton groupName="radioGroup" label="{fieldRepeater.currentItem}" value="{fieldRepeater.currentItem}"/> </mx:Repeater> </mx:Form> <mx:Form label="Child Information" hideEffect="{hideEffect}" showEffect="{showEffect}"> <mx:FormItem> <mx:DataGrid id="childinfo"> <mx:columns> <mx:DataGridColumn headerText="Child Name" dataField="strName"/> <mx:DataGridColumn headerText="School Name" dataField="strSchoolName"/> <mx:DataGridColumn headerText="Pick Up Point" dataField="strPickUpPointName"/> <mx:DataGridColumn headerText="Drop Down Point" dataField="strDropDownPointName"/> </mx:columns> </mx:DataGrid> </mx:FormItem> <mx:FormItem> <mx:Button label="click here to see bus location"/> </mx:FormItem> </mx:Form> <mx:Form label="Bus Location" hideEffect="{hideEffect}" showEffect="{showEffect}"> <maps:Map3D xmlns:maps="com.google.maps.*" mapevent_mappreinitialize="onMapPreinitialize(event)" id="buslocation" width="100%" height="100%" url="http://code.google.com/apis/maps/" key="ABQIAAAAXuX6aG-r_N0-tQNxUEV-vRSE8al1BQssMxLXJiP75kIjR3ssLxT3D52_u94hI-dMIkD72FmnK-P4og"/> </mx:Form> <mx:Form label="Bus path" hideEffect="{hideEffect}" showEffect="{showEffect}"> <maps:Map3D xmlns:maps="com.google.maps.*" mapevent_mappreinitialize="onMapPreinitialize(event)" id="buspath" width="100%" height="100%" url="http://code.google.com/apis/maps/" key="ABQIAAAAXuX6aG-r_N0-tQNxUEV-vRSE8al1BQssMxLXJiP75kIjR3ssLxT3D52_u94hI-dMIkD72FmnK-P4og"/> </mx:Form> </mx:TabNavigator> </mx:Panel> I am getting this error :- TypeError: Error #1009: Cannot access a property or method of a null object reference. at com.google.maps.geom::Geometry$/computeSeparatingAxes() at com.google.maps.geom::TileEnumerator/enumerateTiles() at com.google.maps.core::PerspectiveTilePane/computeOptimalSet() at com.google.maps.core::PerspectiveTilePane/render() at com.google.maps.core::PerspectiveTilePane/configure() at com.google.maps.managers::PerspectiveTileManager/updateView() at com.google.maps.managers::PerspectiveTileManager/initializePanes() at com.google.maps.managers::PerspectiveTileManager/onInitialize() at MethodInfo-190() at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298] at com.google.maps.wrappers::BaseEventDispatcher/dispatchEvent() at com.google.maps.wrappers::EventDispatcherWrapper/dispatchEvent() at com.google.maps.core::MapImpl/size() at com.google.maps.core::MapImpl/setSize() at com.google.maps.wrappers::IMapWrapper/setSize() at com.google.maps::Map/internalSetSize() at com.google.maps::Map/onUIComponentResized() at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298] at mx.core::UIComponent/dispatchResizeEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:7077] at mx.core::UIComponent/setActualSize()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:6706] at mx.containers.utilityClasses::BoxLayout/updateDisplayList()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\containers\utilityClasses\BoxLayout.as:219] at mx.containers::Form/updateDisplayList()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\containers\Form.as:375] at mx.core::UIComponent/validateDisplayList()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:6351] at mx.core::Container/validateDisplayList()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\Container.as:2677] at mx.managers::LayoutManager/validateDisplayList()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\LayoutManager.as:622] at mx.managers::LayoutManager/doPhasedInstantiation()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\LayoutManager.as:695] at Function/http://adobe.com/AS3/2006/builtin::apply() at mx.core::UIComponent/callLaterDispatcher2()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8628] at mx.core::UIComponent/callLaterDispatcher()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8568] Please resolve my issue.

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• Finding begin and end of year/month/day/hour

  - by reto

  I'm using the following snipped to find the begin and end of several time periods in Joda. The little devil on my left shoulder says thats the way to go... but I dont believe him. Could anybody with some joda experience take a brief look and tell me that the little guy is right? (It will be only used for UTC datetime objects) Thank you! /* Year */ private static DateTime endOfYear(DateTime dateTime) { return endOfDay(dateTime).withMonthOfYear(12).withDayOfMonth(31); } private static DateTime beginningOfYear(DateTime dateTime) { return beginningOfMonth(dateTime).withMonthOfYear(1); } /* Month */ private static DateTime endOfMonth(DateTime dateTime) { return endOfDay(dateTime).withDayOfMonth(dateTime.dayOfMonth().getMaximumValue()); } private static DateTime beginningOfMonth(DateTime dateTime) { return beginningOfday(dateTime).withDayOfMonth(1); } /* Day */ private static DateTime endOfDay(DateTime dateTime) { return endOfHour(dateTime).withHourOfDay(23); } private static DateTime beginningOfday(DateTime dateTime) { return beginningOfHour(dateTime).withHourOfDay(0); } /* Hour */ private static DateTime beginningOfHour(DateTime dateTime) { return dateTime.withMillisOfSecond(0).withSecondOfMinute(0).withMinuteOfHour(0); } private static DateTime endOfHour(DateTime dateTime) { return dateTime.withMillisOfSecond(999).withSecondOfMinute(59).withMinuteOfHour(59); }

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• XAML Binding to complex value objects

  - by Gus

  I have a complex value object class that has 1) a number or read-only properties; 2) a private constructor; and 3) a number of static singleton instance properties [so the properties of a ComplexValueObject never change and an individual value is instantiated once in the application's lifecycle]. public class ComplexValueClass { /* A number of read only properties */ private readonly string _propertyOne; public string PropertyOne { get { return _propertyOne; } } private readonly string _propertyTwo; public string PropertyTwo { get { return _propertyTwo; } } /* a private constructor */ private ComplexValueClass(string propertyOne, string propertyTwo) { _propertyOne = propertyOne; _propertyTwo = PropertyTwo; } /* a number of singleton instances */ private static ComplexValueClass _complexValueObjectOne; public static ComplexValueClass ComplexValueObjectOne { get { if (_complexValueObjectOne == null) { _complexValueObjectOne = new ComplexValueClass("string one", "string two"); } return _complexValueObjectOne; } } private static ComplexValueClass _complexValueObjectTwo; public static ComplexValueClass ComplexValueObjectTwo { get { if (_complexValueObjectTwo == null) { _complexValueObjectTwo = new ComplexValueClass("string three", "string four"); } return _complexValueObjectTwo; } } } I have a data context class that looks something like this: public class DataContextClass : INotifyPropertyChanged { private ComplexValueClass _complexValueClass; public ComplexValueClass ComplexValueObject { get { return _complexValueClass; } set { _complexValueClass = value; PropertyChanged(this, new PropertyChangedEventArgs("ComplexValueObject")); } } } I would like to write a XAML binding statement to a property on my complex value object that updates the UI whenever the entire complex value object changes. What is the best and/or most concise way of doing this? I have something like: <Object Value="{Binding ComplexValueObject.PropertyOne}" /> but the UI does not update when ComplexValueObject as a whole changes.

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• Windows Service Conundrum

  - by Paul Johnson

  All, I have a Custom object which I have written using VB.NET (.net 2.0). The object instantiates its own threading.timer object and carries out a number of background process including periodic interrogation of an oracle database and delivery of emails via smtp according to data detected in the database. The following is the code implemented in the windows service class Public Class IncidentManagerService 'Fakes Private _fakeRepoFactory As IRepoFactory Private _incidentRepo As FakeIncidentRepo Private _incidentDefinitionRepo As FakeIncidentDefinitionRepo Private _incManager As IncidentManager.Session 'Real Private _started As Boolean = False Private _repoFactory As New NHibernateRepoFactory Private _psalertsEventRepo As IPsalertsEventRepo = _repoFactory.GetPsalertsEventRepo() Protected Overrides Sub OnStart(ByVal args() As String) ' Add code here to start your service. This method should set things ' in motion so your service can do its work. If Not _started Then Startup() _started = True End If End Sub Protected Overrides Sub OnStop() 'Tear down class variables in order to ensure the service stops cleanly _incManager.Dispose() _incidentDefinitionRepo = Nothing _incidentRepo = Nothing _fakeRepoFactory = Nothing _repoFactory = Nothing End Sub Private Sub Startup() Dim incidents As IList(Of Incident) = Nothing Dim incidentFactory As New IncidentFactory incidents = IncidentFactory.GetTwoFakeIncidents _repoFactory = New NHibernateRepoFactory _fakeRepoFactory = New FakeRepoFactory(incidents) _incidentRepo = _fakeRepoFactory.GetIncidentRepo _incidentDefinitionRepo = _fakeRepoFactory.GetIncidentDefinitionRepo 'Start an incident manager session _incManager = New IncidentManager.Session(_incidentRepo, _incidentDefinitionRepo, _psalertsEventRepo) _incManager.Start() End Sub End Class After a little bit of experimentation I arrived at the above code in the OnStart method. All functionality passed testing when deployed from VS2005 on my development PC, however when deployed on a true target machine, the service would not start and responds with the following message: "The service on local computer started and then stopped..." Am I going about this the correct way? If not how can I best implement my incident manager within the confines of the Windows Service class. It seems pointless to implement a timer for the incidentmanager because this already implements its own timer... Any assistance much appreciated. Kind Regards Paul J.

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• How to serialize a protected property in wcf

  - by Denis Rosca

  Hello everyone, I have to classes (Person and Address) that i need to send via wcf, the classes look like this: public class PersoanaFizica :IExtensibleDataObject { [DataMember] private Guid _id; [DataMember(Name = "Id")] protected virtual Guid Id { get { return _id; } set { _id = value; } } private ExtensionDataObject _extensionData; public virtual ExtensionDataObject ExtensionData { get { return _extensionData; } set { _extensionData = value; } } private string _firstName; [Searchable(PropertyName="FirstName")] [DataMember] public virtual string FirstName { get { return this._firstName; } set { this._firstName = value; } } private string _lastName; [Searchable(PropertyName="LastName")] [DataMember] public virtual string LastName { get { return this._lastName; } set { this. _lastName = value; } } private Address _address; [Searchable(PropertyName="Address")] [DataMember] public virtual Address Address { get { return this._address; } set { this._address = value; } } } public class Address : IExtensibleDataObject { [DataMember] private Guid _id; [DataMember] public virtual Guid Id { get { return _id; } set { _id = value; } } private ExtensionDataObject _extensionData; public virtual ExtensionDataObject ExtensionData { get { return _extensionData; } set { _extensionData = value; } } private string _country; [Searchable(PropertyName="Country")] [DataMember] public virtual string Country { get { return this._country; } set { this._country = value; } } // and some other properties related to the address } The problem is that when i try to send them via wcf, the client recieves the Id properties set to 00000-0000-00000-00000 or smth like this. Any idea why this is happening? And how to serialize the proper values? Thanks,Denis.

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• Adding time zone hours difference to time

  - by Hwang

  I know there's a much better and correct way to do it, but i need a temporarily solutions. I need to add in extra hours to the time, and the day will change automatically too. How should I change the code below? package { public class getTime { private var today:Date=new Date(); private var hour:uint=today.getHours(); private var minute:uint=today.getMinutes(); private var month:uint=today.getMonth(); private var monthArray:Array=new Array('January','February','March','April','May','June','July','August','September','October','November','December'); private var time:String = getUSClockTime(today.getHours(), today.getMinutes()); public var dateNtime:String=(time+", " +today.getDate()+" "+monthArray[month]+" "+today.getFullYear());; public function getTime() { } private function getUSClockTime(hrs:uint, mins:uint):String { var modifier:String="PM"; var minLabel:String=doubleDigitFormat(mins); if (hrs>12) { hrs=hrs-12; } else if (hrs == 0) { modifier="AM"; hrs=12; } else if (hrs < 12) { modifier="AM"; } return (doubleDigitFormat(hrs) + ":" + minLabel + " " + modifier); } private function doubleDigitFormat(num):String { if (num<10) { return ("0" + num); } return num; } } }

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• How to query JDO persistent objects in unowned relationship model?

  - by Paul B

  Hello, I'm trying to migrate my app from PHP and RDBMS (MySQL) to Google App Engine and have a hard time figuring out data model and relationships in JDO. In my current app I use a lot of JOIN queries like: SELECT users.name, comments.comment FROM users, comments WHERE users.user_id = comments.user_id AND users.email = '[email protected]' As I understand, JOIN queries are not supported in this way so the only(?) way to store data is using unowned relationships and "foreign" keys. There is a documentation regarding that, but no useful examples. So far I have something like this: @PersistenceCapable public class Users {     @PrimaryKey     @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)     private Key key;     @Persistent     private String name;         @Persistent     private String email;         @Persistent     private Set<Key> commentKeys;     // Accessors... } @PersistenceCapable public class Comments {     @PrimaryKey     @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)     private Key key;     @Persistent     private String comment;         @Persistent     private Date commentDate;     @Persistent     private Key userKey;     // Accessors... } So, how do I get a list with commenter's name, comment and date in one query? I see how I probably could get away with 3 queries but that seems wrong and would create unnecessary overhead. Please, help me out with some code examples. -- Paul.

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• Eclipselink: Create objects from JOIN query

  - by Raven

  Hi, I have a SQL query SELECT * FROM Thing AS a JOIN Thing_Property AS b ON a.id=b.Thing_ID JOIN Property AS c ON b.properties_ID = c.id JOIN Item AS d ON c.item_ID = d.id ORDER BY a.name, d.name and I Eclipselink to create my object model with it. Here is the model: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end but I can not figure out, how to make Eclipselink create the model from that query. Can you help?

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• TabHost disappears after locking the phone and reopening it:

  - by Emil Adz

  I have a weird issue with my TabHost in my FragmentActivity that contains a ViewPager. The problem is that when I close my phone (press the power button) while I use my application, and then I turn back the phone and my application gets reopened, at this point my TabHost is missing. So the closing of my phone is causes the TabHost to disappear. My guess would be that I need to save my tabHost state in the saveInstanceState object, and restore it in onResume I only have no idea how it's done. here is my code for the FragmentActivity: public class TabsViewPagerFragmentActivity extends FragmentActivity implements ViewPager.OnPageChangeListener, TabHost.OnTabChangeListener { static final String TAG = TabsViewPagerFragmentActivity.class.getSimpleName(); private TabHost mTabHost; private ViewPager mViewPager; private HashMap<String, TabInfo> mapTabInfo; public ViewPagerAdapter mPagerAdapter; private TextView tvReportName, tvTabTitle; private Button bBackToParameters; private Dialog progressDialog; private SGRaportManagerAppObj application; private int numberOfTabs = 0; private Display display; public static final int POPUP_MARGIN = 6; LeftSideMenu leftSideMenu; public void NotifyTabActivityViewPagerAdapter() { mPagerAdapter.notifyDataSetChanged(); } public ViewPagerAdapter getTabActivityViewPagerAdapter() { return mPagerAdapter; } public ViewPager getTabActivityViewPager() { return mViewPager; } public void setCurrentTabTitle (String title) { tvTabTitle.setText(title); Log.d(TAG, "set tab title from activity: "+title); } /** * Maintains extrinsic info of a tab's construct */ private class TabInfo { private String tag; private Class<?> clss; private Bundle args; private Fragment fragment; TabInfo(String tag, Class<?> clazz, Bundle args) { this.tag = tag; this.clss = clazz; this.args = args; } } /** * A simple factory that returns dummy views to the Tabhost */ class TabFactory implements TabContentFactory { private final Context mContext; /** * @param context */ public TabFactory(Context context) { mContext = context; } /** (non-Javadoc) * @see android.widget.TabHost.TabContentFactory#createTabContent(java.lang.String) */ public View createTabContent(String tag) { View v = new View(mContext); v.setMinimumWidth(0); v.setMinimumHeight(0); return v; } } /** (non-Javadoc) * @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle) */ public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); application = SGRaportManagerAppObj.getInstance(); display = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay(); // Inflate the layout setContentView(R.layout.tabs_screen_activity_layout); tvTabTitle = (TextView) findViewById(R.id.tvTabName); tvReportName = (TextView)findViewById(R.id.tvReportName); tvReportName.setText(application.currentReport.getName()+ " - "); bBackToParameters = (Button) findViewById(R.id.bBackToParameters); leftSideMenu = (LeftSideMenu) findViewById(R.id.leftSideMenu); applyOnClickListenerToLeftSideMenu(); findViewById(R.id.showLeftMenuButton).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Display d = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay(); int width = d.getWidth(); View panel = findViewById(R.id.leftSideMenu); View appPanel = findViewById(R.id.appLayout); if (panel.getVisibility() == View.GONE){ appPanel.setLayoutParams(new LinearLayout.LayoutParams(width, LayoutParams.FILL_PARENT)); panel.setVisibility(View.VISIBLE); applyOnClickListenerToLeftSideMenu(); }else{ ToggleButton button = (ToggleButton) findViewById(R.id.showLeftMenuButton); button.setChecked(false); panel.setVisibility(View.GONE); } } }); // Initialise the TabHost progressDialog = DialogUtils.createProgressDialog(this, this.getString(R.string.populating_view_pager)); progressDialog.show(); if (SGRaportManagerAppObj.getInstance().parametersRepository.getParametersRepository().size() == 0) { bBackToParameters.setText(R.string.back_to_report_list); } this.initialiseTabHost(savedInstanceState); if (savedInstanceState != null) { mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); //set the tab as per the saved state } // Intialise ViewPager this.intialiseViewPager(); progressDialog.dismiss(); } /** (non-Javadoc) * @see android.support.v4.app.FragmentActivity#onSaveInstanceState(android.os.Bundle) */ protected void onSaveInstanceState(Bundle outState) { outState.putString("tab", mTabHost.getCurrentTabTag()); //save the tab selected super.onSaveInstanceState(outState); } /** * Initialise ViewPager */ public void intialiseViewPager() { List<Fragment> fragments = new Vector<Fragment>(); // TabInfo tabInfo = null; if (application.getCurrentDataSource().equals(DataSource.SSRS)) { numberOfTabs = application.currentReport.getTabsList().size(); } else if (application.getCurrentDataSource().equals(DataSource.SGRDL)) { numberOfTabs = application.currentReport.getODTabsList().size(); Log.d(TAG, "CURRENT REPORT FROM VIEW PAGER: "+ application.currentReport.toString()); } Log.d(TAG,"Current Tabs number from TabsViewPager activity: " +numberOfTabs); if (application.getCurrentDataSource().equals(DataSource.SSRS)) { for (int i = 0; i < numberOfTabs; i++) { Tab tempTab = application.currentReport.getTabsList().get(i); if (tempTab.getTabTemplateId() == 7) { GridFragment gridFragment = new GridFragment(tempTab); fragments.add(gridFragment); } else if (tempTab.getTabTemplateId() == 8) { NewChartFragment chartFragment = new NewChartFragment(tempTab, this); fragments.add(chartFragment); } } } else if (application.getCurrentDataSource().equals(DataSource.SGRDL)) { for (int i = 0; i < numberOfTabs; i++) { ODTab tempTab = application.currentReport.getODTabsList().get(i); if (tempTab.getTabType().equals(ODGrid.XML_GRID_ELEMENT)) { GridFragment gridFragment = GridFragment.newInstance(tempTab.getTabId()); fragments.add(gridFragment); } else if (tempTab.getTabType().equals(ODChart.XML_CHART_ELEMENT)) { NewChartFragment chartFragment = NewChartFragment.newInstance(tempTab.getTabId()); fragments.add(chartFragment); } } } Log.d(TAG, "Current report fragments set to adapter: "+fragments.toString()); /* if (this.mPagerAdapter == null) { this.mPagerAdapter = new ViewPagerAdapter(super.getSupportFragmentManager(), fragments); } else { this.mPagerAdapter.removeAllFragments(); this.mPagerAdapter.addFragmentsListToAdapter(fragments); } */ this.mPagerAdapter = new ViewPagerAdapter(super.getSupportFragmentManager(), fragments); this.mViewPager = (ViewPager)super.findViewById(R.id.pager); // this.mViewPager.setAdapter(null); this.mViewPager.setAdapter(this.mPagerAdapter); this.mViewPager.setOffscreenPageLimit(0); this.mViewPager.setOnPageChangeListener(this); Log.d(TAG, "Adapter initialized!"); } /** * Initialise the Tab Host */ public void initialiseTabHost(Bundle args) { mTabHost = (TabHost)findViewById(android.R.id.tabhost); /* //new edit if (mTabHost.getChildCount() > 0) { mTabHost.removeAllViews(); } */ mTabHost.setup(); TabInfo tabInfo = null; mapTabInfo = new HashMap<String, TabsViewPagerFragmentActivity.TabInfo>(); if (args != null) {} else { if (application.getCurrentDataSource().equals(DataSource.SSRS)) { int numberOfTabs = application.currentReport.getTabsList().size(); for (int i = 0; i < numberOfTabs; i++) { Tab tempTab = application.currentReport.getTabsList().get(i); if (tempTab.getTabTemplateId() == 7) { //GridFragment gridFragment = new GridFragment(tempTab); TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab "+String.valueOf(i)).setIndicator("Tab "+String.valueOf(i)), ( tabInfo = new TabInfo("Tab "+String.valueOf(i), GridFragment.class, args))); this.mapTabInfo.put(tabInfo.tag, tabInfo); } else if (tempTab.getTabTemplateId() == 8) { TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab "+String.valueOf(i)).setIndicator("Tab "+String.valueOf(i)), ( tabInfo = new TabInfo("Tab "+String.valueOf(i), NewChartFragment.class, args))); this.mapTabInfo.put(tabInfo.tag, tabInfo); } } } else if (application.getCurrentDataSource().equals(DataSource.SGRDL)) { int numberOfTabs = application.currentReport.getODTabsList().size(); for (int i = 0; i < numberOfTabs; i++) { ODTab tempTab = application.currentReport.getODTabsList().get(i); // Log.d(TAG,"Crashed Tab type: "+ tempTab.getTabType()); if (tempTab.getTabType().equals(ODGrid.XML_GRID_ELEMENT)) { //GridFragment gridFragment = new GridFragment(tempTab); TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab "+String.valueOf(i)).setIndicator("Tab "+String.valueOf(i)), ( tabInfo = new TabInfo("Tab "+String.valueOf(i), GridFragment.class, args))); this.mapTabInfo.put(tabInfo.tag, tabInfo); } else if (tempTab.getTabType().equals(ODChart.XML_CHART_ELEMENT)) { TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab "+String.valueOf(i)).setIndicator("Tab "+String.valueOf(i)), ( tabInfo = new TabInfo("Tab "+String.valueOf(i), NewChartFragment.class, args))); this.mapTabInfo.put(tabInfo.tag, tabInfo); } } } } // Default to first tab //this.onTabChanged("Tab1"); // mTabHost.setOnTabChangedListener(this); } /** * Add Tab content to the Tabhost * @param activity * @param tabHost * @param tabSpec * @param clss * @param args */ private static void AddTab(TabsViewPagerFragmentActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) { // Attach a Tab view factory to the spec ImageView indicator = new ImageView(activity.getBaseContext()); indicator.setPadding(10, 10, 10, 10); indicator.setImageResource(R.drawable.tab_select_icon_selector); LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT); lp.setMargins(10, 10, 10, 10); indicator.setLayoutParams(lp); tabSpec.setIndicator(indicator); tabSpec.setContent(activity.new TabFactory(activity)); tabHost.addTab(tabSpec); } /** (non-Javadoc) * @see android.widget.TabHost.OnTabChangeListener#onTabChanged(java.lang.String) */ public void onTabChanged(String tag) { //TabInfo newTab = this.mapTabInfo.get(tag); int pos = this.mTabHost.getCurrentTab(); this.mViewPager.setCurrentItem(pos); } /* (non-Javadoc) * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrolled(int, float, int) */ @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { // TODO Auto-generated method stub } /* (non-Javadoc) * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageSelected(int) */ @Override public void onPageSelected(int position) { // TODO Auto-generated method stub this.mTabHost.setCurrentTab(position); } /* (non-Javadoc) * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrollStateChanged(int) */ @Override public void onPageScrollStateChanged(int state) { // TODO Auto-generated method stub } How would one save the state of the TabHost and restore it in onResume? Any help would be very appreciated.

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• Object Oriented Programming Problem

  - by Danny Love

  I'm designing a little CMS using PHP whilst putting OOP into practice. I've hit a problem though. I have a page class, whos constructor accepts a UID and a slug. This is then used to set the properties (unless the page don't exist in which case it would fail). Anyway, I wanted to implement a function to create a page, and I thought ... what's the best way to do this without overloading the constructor. What would the correct way, or more conventional method, of doing this be? My code is below: <?php class Page { private $dbc; private $title; private $description; private $image; private $tags; private $owner; private $timestamp; private $views; public function __construct($uid, $slug) { } public function getTitle() { return $this->title; } public function getDescription() { if($this->description != NULL) { return $this->description; } else { return false; } } public function getImage() { if($this->image != NULL) { return $this->image; } else { return false; } } public function getTags() { if($this->tags != NULL) { return $this->tags; } else { return false; } } public function getOwner() { return $this->owner; } public function getTimestamp() { return $this->timestamp; } public function getViews() { return $this->views; } public function createPage() { // Stuck? } }

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• How deserealizing JSON with GSON

  - by loko

  I have one result of APPI http://developer.yahoo.com/geo/placefinder/guide/examples.html, I need to deserealizing the result JSON of example only with GSON http://where.yahooapis.com/geocode?location=San+Francisco,+CA&flags=J&appid=yourappid But i dont now have to do the class for deserealizing one JSON with array This is the reponse: {"ResultSet": {"version":"1.0", "Error":0, "ErrorMessage":"No error", "Locale":"en_US", "Quality":40, "Found":1, "Results":[ {"quality":40, "latitude":"37.779160", "longitude":"-122.420049", "offsetlat":"37.779160", "offsetlon":"-122.420049", "radius":5000, "name":"", "line1":"", "line2":"San Francisco, CA", "line3":"", "line4":"United States", "house":"", "street":"", "xstreet":"", "unittype":"", "unit":"", "postal":"", "neighborhood":"", "city":"San Francisco", "county":"San Francisco County", "state":"California", "country":"United States", "countrycode":"US", "statecode":"CA", "countycode":"", "uzip":"94102", "hash":"C1D313AD706E3B3C", "woeid":12587707, "woetype":9}] } } Im trying to deserealizing of this way but i couldn´t do that, please help me to do the correct class to get the JSON with GSON. public class LocationAddress { private ResultSet resultset; public static class ResultSet{ private String version; private String Error; private String ErrorMessage; private List<Results> results; } public static class Results{ private String quality; private String latitude; private String longitude; public String getQuality() { return quality; } public void setQuality(String quality) { this.quality = quality; } public String getLatitude() { return latitude; } public void setLatitude(String latitude) { this.latitude = latitude; } public String getLongitude() { return longitude; } public void setLongitude(String longitude) { this.longitude = longitude; } } }

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• Access-specifiers are not foolproof?

  - by Nawaz

  If I've a class like this, class Sample { private: int X; }; Then we cannot access X from outside, so this is illegal, Sample s; s.X = 10; // error - private access But we can make it accessible without editing the class! All we need to do is this, #define private public //note this define! class Sample { private: int X; }; //outside code Sample s; s.X = 10; //no error! Working code at ideone : http://www.ideone.com/FaGpZ That means, we can change the access-specifiers by defining such macros just before the class definition, or before #include <headerfile.h>, #define public private //make public private //or #define protected private //make protected private //or #define so on Isn't it a problem with C++ (Macros/access-specifiers/whatever)? Anyway, the point of this topic is: Using macros, we can easily violate encapsulation. Access-specifiers are not foolproof! Am I right?

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• In a Windows forms application, how can I setup can I set up the SelectedIndexChanged handle for 4 d

  - by Alex

  In a Windows forms application, within a DataGridView, I have 4 different DataGridCombobox controlshow can I set up the handler SelectedIndexChanged handler for the first combobox via the EditingControlShowing event. I added code for a second combobox but the SelectedIndexChanged didn't get wired up. Here's my code. Any advice would be appreciated. private ComboBox countryCombo; private EventHandler countryHandler; private ComboBox partCombo; private EventHandler partHandler; private void dataGridView2_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e) { countryCombo = e.Control as ComboBox; if (countryCombo != null) { //remove any existing handler if there is one countryCombo.SelectedIndexChanged -= countryHandler; //add the new handler countryCombo.SelectedIndexChanged += new EventHandler(countryCombo_SelectedIndexChanged); } if (partCombo != null) { partCombo.SelectedIndexChanged -= partHandler; partCombo.SelectedIndexChanged += new EventHandler(partCombo_SelectedIndexChanged); } } private void countryCombo_SelectedIndexChanged(object sender, EventArgs e) { ComboBox box = (ComboBox) sender; //MessageBox.Show(box.Items.Count.ToString()); int rowNum = dataGridView2.CurrentCell.RowIndex; dataGridView2.BeginEdit(false); dataGridView2.Rows[0].Cells[2].Value = "abcdef"; dataGridView2.EndEdit(); } private void dataGridView2_CellContentClick(object sender, DataGridViewCellEventArgs e) { int cellColumn = e.ColumnIndex; //MessageBox.Show("Column is: " + cellColumn.ToString()); } private void partCombo_SelectedIndexChanged(object sender, EventArgs e) { ComboBox box = (ComboBox)sender; string partNumber = box.SelectedValue as string; // ToDo: now we need to get the HTSUS from the database so we can //populate the field int rowNum = dataGridView2.CurrentCell.RowIndex; dataGridView2.BeginEdit(false); dataGridView2.Rows[0].Cells[2].Value = "abcdef"; dataGridView2.EndEdit(); } } Al D.

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• Random syntactical error in my php code that I can't find

  - by user348538

  Ordinarily I hate coming here with newbie code questions but nobody can find the error with this code. Maybe you guys can :-) <?php defined('SYSPATH') or die('No direct script access.'); /** * to interact with photos * * @author Max Padraig Wolfgang Bucknell-Leahy */ class Model_Photos { private $apiKey = '12664498208a1380fe49fb1b5a238ef0'; private $secret = '03d43dee65a34513'; private $perms = 'read'; private $sigString = 'test'; private $apiSig = md5($_sigString); private $authArray = array('api_key' => $apiKey, 'perms' => $perms, 'api_sig' => $apiSig); private $authArrayImploded = implode('&', $authArray); private $authLink = 'http://www.flickr.com/services/auth/?' . $authArrayImploded; public function get_photos($number = 5) { if(file_exists(APPPATH . 'cache/main_cache.xml') { echo $authLink; } else { echo 'not so good'; /** */ } } } $class = new Model_Photos; $class->get_photos; the error is: Parse error: syntax error, unexpected '(', expecting ',' or ';' in /home/p14s9nnd/public_html/testing.php on line 15 Thank you in advance and sorry Regards, Max

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• Is there a better way to throttle a high throughput job?

  - by ChaosPandion

  I created a simple class that shows what I am trying to do without any noise. Feel free to bash away at my code. That's why I posted it here. public class Throttled : IDisposable { private readonly Action work; private readonly Func<bool> stop; private readonly ManualResetEvent continueProcessing; private readonly Timer throttleTimer; private readonly int throttlePeriod; private readonly int throttleLimit; private int totalProcessed; public Throttled(Action work, Func<bool> stop, int throttlePeriod, int throttleLimit) { this.work = work; this.stop = stop; this.throttlePeriod = throttlePeriod; this.throttleLimit = throttleLimit; continueProcessing = new ManualResetEvent(true); throttleTimer = new Timer(ThrottleUpdate, null, throttlePeriod, throttlePeriod); } public void Dispose() { throttleTimer.Dispose(); ((IDisposable)continueProcessing).Dispose(); } public void Execute() { while (!stop()) { if (Interlocked.Increment(ref totalProcessed) > throttleLimit) { lock (continueProcessing) { continueProcessing.Reset(); } if (!continueProcessing.WaitOne(throttlePeriod)) { throw new TimeoutException(); } } work(); } } private void ThrottleUpdate(object state) { Interlocked.Exchange(ref totalProcessed, 0); lock (continueProcessing) { continueProcessing.Set(); } } }

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• How would I associate a "Note" class to 4+ classes without creating lookup table for each associatio

  - by Gthompson83

  Im creating a project tasklist application. I have project, section, task, issue classes, and would like to use one class to be able to add simple notes to any object instance of those classes. The task, issue tables both use a standard identity field as a primary key. The section table has a two field primary key. The project table has a single int primary key defined by the user. Is there a way to associate the note class with each of these without using a seperate lookup table for each class? I'm not so sure my original idea is a decent way to implement this. I considered the following (each variable mapping to a field n the notes table. Private _NoteId As Integer Private _ProjectId As Integer Private _SectionId As Integer Private _SectionId2 As Integer Private _TaskId As Integer Private _IssueId As Integer Private _Note As String Private _UserId As Guid Then I would be able to write seperate methods (getProjectNotes, getTaskNotes) to get notes attached to each class. I started writing this a few weeks ago but got pulled away before i could finish. When revisiting this code today my first thought "this is retarded". Thoughts on drawbacks to this design?

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• PHP classes, parse syntax errors when using 'var' to declare variables

  - by jon

  I am a C# guy trying to translate some of my OOP understanding over to php. I'm trying to make my first class object, and are hitting a few hitches. Here is the beginning of the class: <?php require("Database/UserDB.php"); class User { private var $uid; private var $username; private var $password; private var $realname; private var $email; private var $address; private var $phone; private var $projectArray; public function _construct($username) { $userArray = UserDB::GetUserArray($username); $uid = $userArray['uid']; $username = $userArray['username']; $realname = $userArray['realname']; $email = $userArray['email']; $phone = $userArray['phone']; $i = 1; $projectArray = UserDB::GetUserProjects($this->GetID()); while($projectArray[$i] != null) { $projectArray[$i] = new Project($projectArray[$i]); } UserDB.php is where I have all my static functions interacting with the Database for this User Class. I am getting errors using when I use var, and I'm getting confused. I know I don't HAVE to use var, or declare the variables at all, but I feel it is a better practice to do so. the error is "unexpected T_VAR, expecting T_VARIABLE" When I simply remove var from the declarations it works. Why is this?

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• Checking preconditions or not

  - by Robert Dailey

  I've been wanting to find a solid answer to the question of whether or not to have runtime checks to validate input for the purposes of ensuring a client has stuck to their end of the agreement in design by contract. For example, consider a simple class constructor: class Foo { public: Foo( BarHandle bar ) { FooHandle handle = GetFooHandle( bar ); if( handle == NULL ) { throw std::exception( "invalid FooHandle" ); } } }; I would argue in this case that a user should not attempt to construct a Foo without a valid BarHandle. It doesn't seem right to verify that bar is valid inside of Foo's constructor. If I simply document that Foo's constructor requires a valid BarHandle, isn't that enough? Is this a proper way to enforce my precondition in design by contract? So far, everything I've read has mixed opinions on this. It seems like 50% of people would say to verify that bar is valid, the other 50% would say that I shouldn't do it, for example consider a case where the user verifies their BarHandle is correct, but a second (and unnecessary) check is also being done inside of Foo's constructor.

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• F# Objects &ndash; Part 3 &ndash; it&rsquo;s time to overload&hellip;

  - by MarkPearl

  Okay, some basic examples of overloading in F# Overloading Constructors Assume you have a F# object called person… type Person (firstname : string, lastname : string) = member v.Fullname = firstname + " " + lastname   This only has one constructor. To add additional constructors to the object by explicitly declaring them using the method member new. type Person (firstname : string, lastname : string) = new () = Person("Unknown", "Unknown") member v.Fullname = firstname + " " + lastname   In the code above I added another constructor to the Person object that takes no parameters and then refers to the primary constructor. Using the same technique in the code below I have created another constructor that accepts only the firstname as a parameter to create an object. type Person (firstname : string, lastname : string) = new () = Person("Unknown", "Unknown") new (firstname : string) = Person(firstname, "Unknown") member v.Fullname = firstname + " " + lastname   Overloading Operators So, you can overload operators of objects in F# as well… let’s look at example code… type Person(name : string) = member v.name = name static member (+) (person1 : Person , person2 : Person) = Person(person1.name + " " + person2.name)   In the code above we have overloaded the “+” operator. Whenever we add to Person objects together, it will now create a new object with the combined names…

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