emdiesse - Developer IT

PHP invalid image's and error handling

- by Emdiesse

Using PHP's Image and GD functions you can use the following method to finally output the php image imagepng($image); Sometimes, for whatever reason the image may not be displayed typically the error is not with the image but with the actual php functions not executing successfully. However this causes a blank image to be returned which doesn't help me. What I want to know is, is there a way to detect a blank or an invalid image and create a new image, write the errors to the new image using imagestring() and then display this new (debug) image instead. for example, a successfully displayed image with no errors: $image = imagecreate(256, 256); //create image imagecolortransparent($image, $BLUE); //set transparent imagefilledrectangle($image, 0, 0, 256, 256, $BLUE); //fill with 'transparent colour' //Draw a border round the image imageline($image, 0, 0, 0, 255, $Black); imageline($image, 0, 0, 255, 0, $Black); imageline($image, 255, 0, 255, 255, $Black); imageline($image, 0, 255, 255, 255, $Black); imagestring($image, 1, 10, 10, "I am an image!", $Black); imagepng($image); imagedestroy($image); but if I then introduce some errors in the php script that may or may not be to do with the actual image creation then the php script fails and the image will not be visible... $image = imagecreate(256, 256); //create image imagecolortransparent($image, $BLUE); //set transparent imagefilledrectangle($image, 0, 0, 256, 256, $BLUE); //fill with 'transparent colour' //Draw a border round the image imageline($image, 0, 0, 0, 255, $Black); imageline($image, 0, 0, 255, 0, $Black); imageline($image, 255, 0, 255, 255, $Black); imageline($image, 0, 255, 255, 255, $Black); imagestring($image, 1, 10, 10, "I am an image!", $Black); /* I am here to cause problems with the php script ** and cause the execution to fail, I am a function ** that does't exist... ** ** and I am missing a semi colon! ;)*/ non_existant_function() imagepng($image); imagedestroy($image); At this point I want to create a new image like above but in replacement of the I am an image! text I would put the actual error that has occured.

Read the article

Java PHP posting using URLConnector, PHP file doesn't seem to receive parameters

- by Emdiesse

Hi there, I am trying to post some simple string data to my php script via a java application. My PHP script works fine when I enter the data myself using a web browser (newvector.php?x1=&y1=...) However using my java application the php file does not seem to pick up these parameters, in fact I don't even know if they are sending at all because if I comment out on of the parameters in the java code when I am writing to dta it doesn't actually return, you must enter 6 parameters. newvector.php if(!isset($_GET['x1']) || !isset($_GET['y1']) || !isset($_GET['t1']) || !isset($_GET['x2']) || !isset($_GET['y2']) || !isset($_GET['t2'])){ die("You must include 6 parameters within the URL: x1, y1, t1, x2, y2, t2"); } $x1 = $_GET['x1']; $x2 = $_GET['x2']; $y1 = $_GET['y1']; $y2 = $_GET['y2']; $t1 = $_GET['t1']; $t2 = $_GET['t2']; $insert = " INSERT INTO vectors( x1, x2, y1, y2, t1, t2 ) VALUES ( '$x1', '$x2', '$y1', '$y2', '$t1', '$t2' ) "; if(!mysql_query($insert, $conn)){ die('Error: ' . mysql_error()); } echo "Submitted Data x1=".$x1." y1=".$y1." t1=".$t1." x2=".$x2." y2=".$y2." t2=".$t2; include 'db_disconnect.php'; ?> The java code else if (action.equals("Play")) { for (int i = 0; i < 5; i++) { // data.size() String x1, y1, t1, x2, y2, t2 = ""; String date = "2010-04-03 "; String ms = ".0"; x1 = data.elementAt(i)[1]; y1 = data.elementAt(i)[0]; t1 = date + data.elementAt(i)[2] + ms; x2 = data.elementAt(i)[4]; y2 = data.elementAt(i)[3]; t2 = date + data.elementAt(i)[5] + ms; try { //Create Post String String dta = URLEncoder.encode("x1", "UTF-8") + "=" + URLEncoder.encode(x1, "UTF-8"); dta += "&" + URLEncoder.encode("y1", "UTF-8") + "=" + URLEncoder.encode(y1, "UTF-8"); dta += "&" + URLEncoder.encode("t1", "UTF-8") + "=" + URLEncoder.encode(t1, "UTF-8"); dta += "&" + URLEncoder.encode("x2", "UTF-8") + "=" + URLEncoder.encode(x2, "UTF-8"); dta += "&" + URLEncoder.encode("y2", "UTF-8") + "=" + URLEncoder.encode(y2, "UTF-8"); dta += "&" + URLEncoder.encode("t2", "UTF-8") + "=" + URLEncoder.encode(t2, "UTF-8"); System.out.println(dta); // Send Data To Page URL url = new URL("http://localhost/newvector.php"); URLConnection conn = url.openConnection(); conn.setDoOutput(true); OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); wr.write(dta); wr.flush(); // Get The Response BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream())); String line; while ((line = rd.readLine()) != null) { System.out.println(line); //you Can Break The String Down Here } wr.close(); rd.close(); } catch (Exception exc) { System.out.println("Hmmm!!! " + exc.getMessage()); } }

Read the article

PHP database simulation

- by Emdiesse

I have a PHP script that works by calling items from a database based upon the time they were placed in there and it deletes them if they are older than 5 minutes. Basically, I want to now simulate what would happen if this database was being updated regularly. So I was considering sticking in some code that loads an XML file then goes through and parses that into the database based upon the time data located within a node of the xml data... but the problem there is I want it to continually loop through an enter this data so it'll never actually run the other processes So I was thinking of having another PHP script do that that could do this independantly of the php script that is going to display this data... In theory: I am looking to have a button that I can press and it will then run some php code to load up an XML file from a directory on my web server and then iterate though the data sending the data, to a database, based upon the time within a node in the PHP script and when the script was first called So back to my page that displayed the data... if I continually hit refresh it will contain different results each time because data is being added by the other process and this php script removes the older data when it is refreshed Any information on this? Is there a way I can silently, and safely, run a php script without it being loaded into a browser... like a thread!?

Read the article

Java.lang.NullPointerException when using retreived Image (Unless method is used statically!)

- by Emdiesse

Hi there, This has been doing my head in all day and I have finally decided to resort to asking for help! In my MIDLet I have an instance of the java class ImageFetcher called anImg. Also within my MIDLet I have a command that simply say's fetch, a CommandListener that when detects fetch was clicked runs the function below. This function should simply run public getImage() from the anImg instance of class ImageFetcher which returns an image and then appends/sets this Image onto the form on the display. (You may recognise the getImage() function from the Nokia JavaME Wiki!!!) Instead of any image being displayed this is written to the output terminal in netbeans: Msg: Java.lang.NullPointerException HOWEVER, If I change public getImage() to public static getImage() and replace anImg.getImage() with ImageFetcher.getImage() the image is successfully displayed!!! Thank you for your replies on this issue :) I look forward to going my hair back after this ordeal! FetchImageApp.java ... ... ... private doThis(){ try { Image im; if ((im = anImg.getImage()) != null) { ImageItem ii = new ImageItem(null, im, ImageItem.LAYOUT_DEFAULT, null); // If there is already an image, set (replace) it if (form.size() != 0) { form.set(0, ii); } else // Append the image to the empty form { form.append(ii); } } else { form.append("Unsuccessful download."); } // Display the form with the image display.setCurrent(form); } catch (Exception e) { System.err.println("Msg: " + e.toString()); } } ... ... ... ImageFetcher.java ... ... ... /*-------------------------------------------------- * Open connection and download png into a byte array. *-------------------------------------------------*/ public Image getImage() throws IOException { String url = "http://kenai.com/attachments/wiki_images/chessgame/java-duke-logo.png"; ContentConnection connection = (ContentConnection) Connector.open(url); // * There is a bug in MIDP 1.0.3 in which read() sometimes returns // an invalid length. To work around this, I have changed the // stream to DataInputStream and called readFully() instead of read() // InputStream iStrm = connection.openInputStream(); DataInputStream iStrm = connection.openDataInputStream(); ByteArrayOutputStream bStrm = null; Image im = null; try { // ContentConnection includes a length method byte imageData[]; int length = (int) connection.getLength(); if (length != -1) { imageData = new byte[length]; // Read the png into an array // iStrm.read(imageData); iStrm.readFully(imageData); } else // Length not available... { bStrm = new ByteArrayOutputStream(); int ch; while ((ch = iStrm.read()) != -1) { bStrm.write(ch); } imageData = bStrm.toByteArray(); bStrm.close(); } // Create the image from the byte array im = Image.createImage(imageData, 0, imageData.length); } finally { // Clean up if (iStrm != null) { iStrm.close(); } if (connection != null) { connection.close(); } if (bStrm != null) { bStrm.close(); } } return (im == null ? null : im); } ... ... ...

Developer IT