Information Technology Tips

In this post, I will show you SQL query for calculateing dense rank for MySQL . You know Oracle and SQL Server have the function called DENSE_RANK, which is for returning rank of the value. Unfortunately MySQL doesn't have the built-in function. We can calculate dense rank by nested select for same table with count function. However this strategy is toooo slow because calculating rank by counting number of rows above the target row for every rows. Anyway here is the query for calculating dense rank for MySQL. SELECT id, @rnk:=IF(@preval score, @rnk, @row + 1) AS dns_rnk, @row:= @row+1 AS rnk, @preval:=score as score FROM table # be careful for NULL handling. # if all the values of score column are null, then dns_rank will zero. # please set proper initial value for @preval based on your data. JOIN (SELECT @rnk := 0, @preval :=null, @row := 0) r ORDER BY score DESC The result should be something like this. id dns_rnk rnk score 1 1 1 100 4 2 2 81 ...

Symfony 1.4 is already a legacy framework. But I think a lot of web system still running on it. In this post, I will show you some quick tips for accessing infromation by using sfContext . sfContext provides almost everything you want access. But you should not use context everywhere too much because sfContext is a kind of global objeect and if a lot of codes depends on context, your code will be hard to be tested or maintained, I think. Basic You can access sfContext by following code. sfContext::getInstance(); In sfFilter, you can access sfContext by the following code. $this->getContext(); What Kind of Fields You can access? Routing name $context->getRouting()->getCurrentRouteName(); User $context->getUser(); Request $context->getRequest(); Response $context->getResponse(); Controller $context->getController(); Logger sfContext::getInstance()->getLogger(); Advanced Use Check if http request is secure (e.g. https request). $co...

Recently I was investigating how to capture web page as image. I recently realized that there is a nicer nice component for navigating web page in Java FX. javafx.scene.web.WebView javafx.embed.swing.JFXPanel I referred this stackoverflow post and wrote a Java class for capturing web page and save it as image. Please note that you should include jfxrt.jar, which was in JDK1.7.0_XX/jre/lib, should be added to your classpath. Code Here is an actual code. Please feel free to use it... I am very happy if you give me some feedback for this code. package com.dukesoftware.javafx; import static com.dukesoftware.utils.io.IOUtils.getExtension; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.Map; import java.util.Set; import java.util.concurrent.Executors; import java.util.concurrent.LinkedBlockingQueue; import javafx.application.Platform; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue;...

In my recent post, I was trying to find out easy way to capture we page image. Today, I will show you my small code tip for capturing web page and saving it as image by ActionScript 3.0. WebPageCapture class This is the main class for capturing web page and save it as image. A few points I should comment... In captureAndSave method, I have used timer because even after Complete event is triggered, somehow sometimes web page is not rendered properly... (might be depends on web site or lazy javascript loading.) requstQueue field is for making sure the request is processed one by one after the former image capturing request is done. You can avoid this if you create HTMLLoader instance for each request. Looks default JPEGEncoder is quite slow.... I have googled and found the following great article. If you are interested in performance, see this excellent post . I was amazed actually :D If you are interested in asynchronous encoding, see this marvelous post . I was impressed :D...

I have googled how to create web page thumbnail. Hope this post helps anyone who are trying to create web page image. Java Lunch a native browser from Desktop class and capture active window by Robot class I think this isn't smart way however it should work. Please read this . The disadvantage of this method is you cannot achieve it on off screen. Using SWT Browser Please read this . The biggest disadvantage is again you cannot do it on off screen. Pure Java Solution If you are seeking pure java solution, maybe Cobra or Css Box will help you. Unfortunately Cobra is not updated recently, and Css Box is still very new on the other hand. I hope I can post example of code on this blog in near future.... Using QT-Jambi I'm not familiar with Qt library but this post explains how to create web page image by Qt Jambi , which is java wrapper of Qt Library. The post provides code example, too!! C# Using System.Windows.Forms.WebBrowser this article in www.codeproj...

Read Image as Double Array You might think "We can use Raster#getPixel method if we would like to grab pixels, can't we?". Yes that's true. The key problem is the low performance because getPixel method internally call SampleModel and convert raw value to proper pixel value every method call. So we should call Raster#getPixels method and grab all pixels one method call. I have done similar stuffs in C# and posted on this blog. On the other hand in Java, this is a bit messy because there are a lot of related classes - Raster, ImageIO, Reader, Writer, etc ;). The simplest way I did is: read image as BufferedImage by ImageIO call BufferedImage#getRaster method call Raster#getPixels method Here is an exmple code. public static TemporalImage readImagePixelDoubleArray(InputStream is, int bitPerPixel) throws IOException{ BufferedImage image = ImageIO.read(is); Raster raster = image.getRaster(); int x = raster.getMinX(); int y = raster....

I wrote java program for loading classes at runtime from jar file or class files Hope this post will help somebody... package com.dukesoftware.utils.reflect; import java.io.File; import java.io.FileFilter; import java.io.IOException; import java.net.URI; import java.net.URL; import java.net.URLClassLoader; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.jar.JarEntry; import java.util.jar.JarFile; public class DynamicClassLoader { public static List<Class<?>> readAllClassesFormJarFile(File jarFilePath) throws IOException{ List<Class<?>> classes = new ArrayList<>(); URL[] urls = { new URL("jar:" + jarFilePath.toURI().toURL() + "!/") }; URLClassLoader loader = URLClassLoader.newInstance(urls); for(Enumeration<JarEntry> en = new JarFile(jarFilePath).entries(); en.hasMoreElements();){ final String name = en.nextElement().getName(...

I'm working on Google App Engine for Java (GAEJ) now. Very excited about working on it because can develop Java Web App quite easliy & quickly! However I faced a limitation of image processing on GAEJ. On GAEJ, java.awt pakage.* is not supported. That means we cannot use BufferedImage etc!! As you know, Google provides com.google.appengine.api.images.* for image processing on GAEJ, something like below: ImagesService imagesService = ImagesServiceFactory.getImagesService(); Image srcImage = ImagesServiceFactory.makeImage(srcImageData); // some transformations. Transform crop = ImagesServiceFactory.makeCrop(0.3, 0, 1, 0.70); OutputSettings settings = new OutputSettings(OutputEncoding.PNG); // apply transform Image newImage = imagesService.applyTransform(crop, srcImage, settings); byte[] newImageData = newImage.getImageData(); It can read jpg, png, gif images accroding to the official document. And if transformation is applied, the output binary data becomes png forma...

Some of you feel a bit annoying for writing XPath to specify html element in Selenium Test. I think the easiest way is using Chrome or using Firebug of Firefox. Chrome Right click html area you would like to get XPath, and select "Inspect element" Right click the html element and select "Copy XPath" in the opened area Firebug Right click html area you would like to get XPath, and select "Inspect Element with Firebug" Right click the html element and select "Copy XPath" in the opened area

As you know I am really interested in image processing. For my first step, I wrote the program for reading image as double array in C#. The code is imperfect but I think this will help someone's understand.... Here is an example usage. var original = Bitmap.FromFile(@"C:\temp\test.jpg"); double[,] values = new Bitmap(original).To2DimDoubleArray(); // image processing part! // let's do something fun :D - filtering, binalizing, etc. // for now, removing R value from the image. for (int i = 0, len = values.Length/values.GetLength(0); i < len; i++ ) { //values[0, i] = 0; // a values[1, i] = 0; // r //values[2, i] = 0; // g //values[3, i] = 0; // b } values .ToBitmap(original.Width, original.Height, PixelFormat.Format32bppArgb) .SaveImageAsJpeg(@"c:\temp\test2.jpg", 75); The image processing result of above example program. The left image is original, the right image is the result image which is red value is removed. ...

I have written Dictionary which returns default value if the key is missing in the dictionary. You simply pass lambda function for returning value when the key is missing in Dictionary to its constructor. using System; using System.Collections.Generic; namespace Utility.Data { public class DefaultDictionary<TKey, TValue> : Dictionary<TKey, TValue> { private readonly Func<TKey, TValue> defaulter; public DefaultDictionary(Func<TKey, TValue> defaulter) { this.defaulter = defaulter; } public TValue GetDefaultValueIfMissing(TKey key){ if (ContainsKey(key)) { return this[key]; } return defaulter(key); } } } This is how to use.... var dict = new DefaultDictionary<string, IList<string>>((key) => new List<string>()); // should return empty list var list = dict.GetDefaultValueIfMissing("key1...

C# is a very powerful language. However for this "powerful" perspective, there are various way to achieve something and you might hover among which way to take (at least for me :D). In this post I will focus on "Reflection" and introduce some small code spinets. First we assume this trivial class is defined in Utility assembly. namespace Utility.Sample { public class Target { public string wrapByDoubleQuote(string text) { return "\"" + text + "\""; } } } Get Type from String and Instantiate by Activator // type from reflection Type type = Type.GetType("Utility.Sample.Target"); // instantiate object from Type Target target = Activator.CreateInstance(type) as Target; // invoke method normally Console.WriteLine(target.wrapByDoubleQuote("contents")); Instantiate Object from ConstructorInfo and Invoke Method by Reflection // type from reflectio...

Here is a way to save BufferedImage as JEPG using ImageWriter. public static void writeAsJpeg(BufferedImage image, float quality, File outputFile) throws IOException { ImageWriter writer = getImageWriter("jpg"); JPEGImageWriteParam iwp = new JPEGImageWriteParam(Locale.getDefault()); iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); iwp.setCompressionQuality(quality); try (ImageOutputStream ios = ImageIO.createImageOutputStream(outputFile)){ writer.setOutput(ios); writer.write(null, new IIOImage(image,null,null),iwp); ios.flush(); } finally{ writer.dispose(); } } private static ImageWriter getImageWriter(String ext) { Iterator iter = ImageIO.getImageWritersByFormatName(ext); if (iter.hasNext()) { return iter.next(); } throw new IllegalStateException("Unsupported " + ext); }

PHPで「全角スペース、全角英数字」を対応する「半角」の文字に変換するコードのメモ。 mb_convert_kana($str,"as","UTF-8")

PHPでWindowsのShift-JIS文字列をUTF-8文字列に変換するコードのメモ mb_convert_encoding($str, "UTF-8", "sjis-win");

Here is a utility class for downloading resource and saving as file asynchronously . package utils.file { import flash.events.Event; import flash.events.EventDispatcher; import flash.events.ProgressEvent; import flash.filesystem.File; import flash.filesystem.FileStream; import flash.filesystem.FileMode; import flash.net.URLLoader; import flash.net.URLLoaderDataFormat; import flash.net.URLRequest; public class AsyncFileSaveDownloader extends EventDispatcher { public function AsyncFileSaveDownloader() { } public function download(url:String, path:String):void { var loader:URLLoader = new URLLoader(); loader.dataFormat = URLLoaderDataFormat.BINARY; loader.addEventListener(Event.COMPLETE, completeDownload); loader.load(new URLRequest(url)); function completeDownload(cevt:Event):void { l...

There are a lot of way to copy file in Java. I have wrote sample codes for them. I think Java 7 way will be the normal & standard way soon!! import static com.dukesoftware.utils.common.ExceptionUtils.throwNotImplementedException; import static java.nio.file.StandardCopyOption.REPLACE_EXISTING; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.Reader; import java.io.Writer; import java.net.URI; import java.nio.channels.FileChannel; import java.nio.file.Paths; import org.apache.commons.io.FileUtils; import com.google.common.io.Closeables; import com.google.common.io.Files; public enum Copier { GUAVA{ @Override public void copy(File src, File dest) throws IOException { Files.copy(src, dest); } }, JAVA7{ @...

I wrote an image canvas class which can be automatically re-size image so that it fits the window. The code itself is pretty simple. package com.dukesoftware.utils.swing.others; import java.awt.Graphics; import java.awt.Image; import javax.swing.JPanel; public class AutoResizeImageCanvas extends JPanel{ private Image img; public void setImage(Image img){ this.img = img; } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); final int panelWidth = getWidth(); final int panelHeight = getHeight(); g.fillRect(0, 0, panelWidth, panelHeight); if(img != null){ final int imgWidth = img.getWidth(null); final int imgHeight = img.getHeight(null); final double rW = (double)panelWidth / imgWidth; final double rH = (double)panelHeight / imgHeight; int newWidth; int newHeight; if(rW < rH){ ...

This is my ant build script used for building app. You know FlashDevelop can build swf however it only compiles minimum classes directly used in the program. So I always run ant build script in order to compile all ".as" and ".mxml" source files If you would like to use my ant script, need some preparation.... Flex PMD: You can download Flex PMD, which is used in my ant script, from here . PMD xslt: I just downloaded official sourceforge PMD zip (the version is 5.0.0 when I wrote this article) and simply picked up some useful xslt from pmd-src-5.0.0/etc/xslt My project directory hierarchy is something like this... <?xml version="1.0" encoding="utf-8" ?> <project name="DukeSoftwareBuildAS3" default="all" basedir="."> <property name="root.dir" value=".." /> <property file="${root.dir}/proj.properties" /> <property file="build.prop...

Main flow part code. package utils.tool { import flash.display.Bitmap; import flash.display.BitmapData; import flash.display.Loader; import flash.net.URLRequest; import flash.events.Event; import utils.ImageUtils; public class ImageResizer { private var maxW:int, maxH:int; private var smoothing:Boolean; private var saveFunction:Function; public function ImageResizer(maxW:int, maxH:int, smoothing:Boolean = false, type:String="jpg") { this.maxW = maxW; this.maxH = maxH; this.smoothing = smoothing; if (type === "png") { saveFunction = ImageUtils.saveBitmapDataAsPNGAsync; } else if(type === "jpg"){ saveFunction = ImageUtils.saveBitmapDataAsJPEGAsync; } else { throw new Error("Not Supported"); } } ...

public static function saveBitmapDataAsJPEG(path:String, bitmapData:BitmapData, quality:Number=50.0):void { saveByteData(new JPEGEncoder(quality).encode(bitmapData), path); } public static function saveBitmapDataAsJPEGAsync(path:String, bitmapData:BitmapData, quality:Number=50.0):void { saveByteDataAsync(new JPEGEncoder(quality).encode(bitmapData), path); } public static function saveBitmapDataAsPNG(path:String, bitmapData:BitmapData):void { saveByteData(new PNGEncoder().encode(bitmapData), path); } public static function saveBitmapDataAsPNGAsync(path:String, bitmapData:BitmapData):void { saveByteDataAsync(new PNGEncoder().encode(bitmapData), path); } Here is my IO Utility methods. public static function saveByteData(data:ByteArray, path:String):void { try { var file:File = new File(path); var fs:FileStream = new FileStream(); fs.open(file, FileMode.WRITE); fs.writeBytes(data); fs.close(); } catch (err:IOError) { trace(err); } } public static function saveB...

Javaでmp3ファイルのID3タグを解析するライブラリを色々と調べてみました。参考になれば幸いです。 以下に挙げていくコードは、特に意味のあることをしている訳ではありませんが、 どうやってタグの読み込み、書き換えを行えるかというサンプルとして参考にして頂ければと思います。 MyID3: a Java ID3 Tag Library import java.io.File; import java.io.IOException; import org.cmc.music.common.MusicMetadata; import org.cmc.music.myid3.MusicMetadataSet; import org.cmc.music.myid3.MyID3; /** * {@link http://www.fightingquaker.com/myid3/} */ public class MyID3Tester { public static void main(String[] args) throws IOException { File mp3File = new File("C:\\temp\\music.mp3"); MyID3 id3 = new MyID3(); MusicMetadataSet src_set = id3.read(mp3File); // read metadata if (src_set == null){ System.out.println("could not read data"); return; } // You can extract simplified information MusicMetadata metadata = src_set.getSimplified(); System.out.println(metadata.getArtist()); System.out.println(metadata.getAlbum()); // this doesn't work for me somehow :( System.out.println(metad...

If you would like to check available font on Java environment, you should use this method. GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames(); The following code is utility class for Font. package com.dukesoftware.utils.common; import java.awt.Font; import java.awt.GraphicsEnvironment; import java.util.Arrays; public class FontUtils { public static void main(String[] args) { printAvailableFonts(); } public static void printAvailableFonts() { System.out.println(Arrays.toString(GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames())); } public static boolean isAvailableFont(String font){ GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); final String[] fontNames = ge.getAvailableFontFamilyNames(); for(String name: fontNames){ if(name.equals(font)){ return true; } } return false; ...

I have developed very very simple youtube sample application on Google App Engine. Internally I have used FreeMarker and Spring. The purpose of this blog entry is just giving hints how to use Spring + FreeMarker on GAEJ with youtube API example. Youtube API Here is the code for extracting video url etc from Youtube API response. I frequently use JDOM for parsing XML. package com.dukesoftware.gaej.youtube; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.util.ArrayList; import java.util.List; import org.jdom.Document; import org.jdom.Element; import org.jdom.JDOMException; import org.jdom.Namespace; import org.jdom.input.SAXBuilder; import org.jdom.xpath.XPath; import com.dukesoftware.utils.io.JDOMUtils; import com.dukesoftware.utils.io.MinimumIOUtils; public class YouTube { private final static XPath XPATH_MEDIA; private final static Namespace NS_MEDIA = Namesp...