20 very useful Java code snippets for Java Developers

java-duke-teachingFollowing are few very useful Java code snippets for Java developers. Few of them are written by me and few are taken from other code reference. Feel free to comment about the code and also add your code snippet. [ad#singleblogtop-linkad]

1. Converting Strings to int and int to String

String a = String.valueOf(2); //integer to numeric string int i = Integer.parseInt(a); //numeric string to an int
Code language: Java (java)

2. Append text to file in Java

Updated: Thanks Simone for pointing to exception. I have changed the code.
BufferedWriter out = null; try { out = new BufferedWriter(new FileWriter(”filename”, true)); out.write(”aString”); } catch (IOException e) { // error processing code } finally { if (out != null) { out.close(); } }
Code language: Java (java)

3. Get name of current method in Java

String methodName = Thread.currentThread().getStackTrace()[1].getMethodName();
Code language: Java (java)

4. Convert String to Date in Java

java.util.Date = java.text.DateFormat.getDateInstance().parse(date String);
Code language: Java (java)
SimpleDateFormat format = new SimpleDateFormat( "dd.MM.yyyy" ); Date date = format.parse( myString );
Code language: Java (java)

5. Connecting to Oracle using Java JDBC

public class OracleJdbcTest { String driverClass = "oracle.jdbc.driver.OracleDriver"; Connection con; public void init(FileInputStream fs) throws ClassNotFoundException, SQLException, FileNotFoundException, IOException { Properties props = new Properties(); props.load(fs); String url = props.getProperty("db.url"); String userName = props.getProperty("db.user"); String password = props.getProperty("db.password"); Class.forName(driverClass); con=DriverManager.getConnection(url, userName, password); } public void fetch() throws SQLException, IOException { PreparedStatement ps = con.prepareStatement("select SYSDATE from dual"); ResultSet rs = ps.executeQuery(); while (rs.next()) { // do the thing you do } rs.close(); ps.close(); } public static void main(String[] args) { OracleJdbcTest test = new OracleJdbcTest(); test.init(); test.fetch(); } }
Code language: Java (java)

6. Convert Java util.Date to sql.Date

[ad] This snippet shows how to convert a java util Date into a sql Date for use in databases.
java.util.Date utilDate = new java.util.Date(); java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
Code language: Java (java)

7. Java Fast File Copy using NIO

public static void fileCopy( File in, File out ) throws IOException { FileChannel inChannel = new FileInputStream( in ).getChannel(); FileChannel outChannel = new FileOutputStream( out ).getChannel(); try { // inChannel.transferTo(0, inChannel.size(), outChannel); // original -- apparently has trouble copying large files on Windows // magic number for Windows, 64Mb - 32Kb) int maxCount = (64 * 1024 * 1024) - (32 * 1024); long size = inChannel.size(); long position = 0; while ( position < size ) { position += inChannel.transferTo( position, maxCount, outChannel ); } } finally { if ( inChannel != null ) { inChannel.close(); } if ( outChannel != null ) { outChannel.close(); } } } [/code] <h2>8. Create Thumbnail of an image in Java</h2> <!-- wp:code {"language": "java"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> private void createThumbnail(String filename, int thumbWidth, int thumbHeight, int quality, String outFilename) throws InterruptedException, FileNotFoundException, IOException { // load image from filename Image image = Toolkit.getDefaultToolkit().getImage(filename); MediaTracker mediaTracker = new MediaTracker(new Container()); mediaTracker.addImage(image, 0); mediaTracker.waitForID(0); // use this to test for errors at this point: System.out.println(mediaTracker.isErrorAny()); // determine thumbnail size from WIDTH and HEIGHT double thumbRatio = (double)thumbWidth / (double)thumbHeight; int imageWidth = image.getWidth(null); int imageHeight = image.getHeight(null); double imageRatio = (double)imageWidth / (double)imageHeight; if (thumbRatio < imageRatio) { thumbHeight = (int)(thumbWidth / imageRatio); } else { thumbWidth = (int)(thumbHeight * imageRatio); } // draw original image to thumbnail image object and // scale it to the new size on-the-fly BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB); Graphics2D graphics2D = thumbImage.createGraphics(); graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR); graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null); // save thumbnail image to outFilename BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outFilename)); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage); quality = Math.max(0, Math.min(quality, 100)); param.setQuality((float)quality / 100.0f, false); encoder.setJPEGEncodeParam(param); encoder.encode(thumbImage); out.close(); } [/code] <h2>9. Creating JSON data in Java</h2> Read <a href="https://www.viralpatel.net/creating-parsing-json-data-with-java-servlet-struts-jsp-json/">this article</a> for more details. Download JAR file <a href="https://www.viralpatel.net/download/json/json-rpc-1.0.jar">json-rpc-1.0.jar (75 kb)</a> <!-- wp:code {"language": "java"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> import org.json.JSONObject; ... ... JSONObject json = new JSONObject(); json.put("city", "Mumbai"); json.put("country", "India"); ... String output = json.toString(); ...
Code language: Java (java)

10. PDF Generation in Java using iText JAR

Read this article for more details.
import java.io.File; import java.io.FileOutputStream; import java.io.OutputStream; import java.util.Date; import com.lowagie.text.Document; import com.lowagie.text.Paragraph; import com.lowagie.text.pdf.PdfWriter; public class GeneratePDF { public static void main(String[] args) { try { OutputStream file = new FileOutputStream(new File("C:\\Test.pdf")); Document document = new Document(); PdfWriter.getInstance(document, file); document.open(); document.add(new Paragraph("Hello Kiran")); document.add(new Paragraph(new Date().toString())); document.close(); file.close(); } catch (Exception e) { e.printStackTrace(); } } }
Code language: Java (java)

11. HTTP Proxy setting in Java

Read this article for more details.
System.getProperties().put("http.proxyHost", "someProxyURL"); System.getProperties().put("http.proxyPort", "someProxyPort"); System.getProperties().put("http.proxyUser", "someUserName"); System.getProperties().put("http.proxyPassword", "somePassword");
Code language: Java (java)

12. Java Singleton example

Read this article for more details. Update: Thanks Markus for the comment. I have updated the code and changed it to more robust implementation.
public class SimpleSingleton { private static SimpleSingleton singleInstance = new SimpleSingleton(); //Marking default constructor private //to avoid direct instantiation. private SimpleSingleton() { } //Get instance for class SimpleSingleton public static SimpleSingleton getInstance() { return singleInstance; } }
Code language: Java (java)
One more implementation of Singleton class. Thanks to Ralph and Lukasz Zielinski for pointing this out.
public enum SimpleSingleton { INSTANCE; public void doSomething() { } } //Call the method from Singleton: SimpleSingleton.INSTANCE.doSomething();
Code language: Java (java)

13. Capture screen shots in Java

Read this article for more details.
import java.awt.Dimension; import java.awt.Rectangle; import java.awt.Robot; import java.awt.Toolkit; import java.awt.image.BufferedImage; import javax.imageio.ImageIO; import java.io.File; ... public void captureScreen(String fileName) throws Exception { Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); Rectangle screenRectangle = new Rectangle(screenSize); Robot robot = new Robot(); BufferedImage image = robot.createScreenCapture(screenRectangle); ImageIO.write(image, "png", new File(fileName)); } ...
Code language: Java (java)

14. Files-Directory listing in Java

File dir = new File("directoryName"); String[] children = dir.list(); if (children == null) { // Either dir does not exist or is not a directory } else { for (int i=0; i < children.length; i++) { // Get filename of file or directory String filename = children[i]; } } // It is also possible to filter the list of returned files. // This example does not return any files that start with `.'. FilenameFilter filter = new FilenameFilter() { public boolean accept(File dir, String name) { return !name.startsWith("."); } }; children = dir.list(filter); // The list of files can also be retrieved as File objects File[] files = dir.listFiles(); // This filter only returns directories FileFilter fileFilter = new FileFilter() { public boolean accept(File file) { return file.isDirectory(); } }; files = dir.listFiles(fileFilter); [/code] <h2>15. Creating ZIP and JAR Files in Java</h2> <!-- wp:code {"language": "java"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> import java.util.zip.*; import java.io.*; public class ZipIt { public static void main(String args[]) throws IOException { if (args.length < 2) { System.err.println("usage: java ZipIt Zip.zip file1 file2 file3"); System.exit(-1); } File zipFile = new File(args[0]); if (zipFile.exists()) { System.err.println("Zip file already exists, please try another"); System.exit(-2); } FileOutputStream fos = new FileOutputStream(zipFile); ZipOutputStream zos = new ZipOutputStream(fos); int bytesRead; byte[] buffer = new byte[1024]; CRC32 crc = new CRC32(); for (int i=1, n=args.length; i < n; i++) { String name = args[i]; File file = new File(name); if (!file.exists()) { System.err.println("Skipping: " + name); continue; } BufferedInputStream bis = new BufferedInputStream( new FileInputStream(file)); crc.reset(); while ((bytesRead = bis.read(buffer)) != -1) { crc.update(buffer, 0, bytesRead); } bis.close(); // Reset to beginning of input stream bis = new BufferedInputStream( new FileInputStream(file)); ZipEntry entry = new ZipEntry(name); entry.setMethod(ZipEntry.STORED); entry.setCompressedSize(file.length()); entry.setSize(file.length()); entry.setCrc(crc.getValue()); zos.putNextEntry(entry); while ((bytesRead = bis.read(buffer)) != -1) { zos.write(buffer, 0, bytesRead); } bis.close(); } zos.close(); } } [/code] <h2>16. Parsing / Reading XML file in Java</h2> Sample XML file. <!-- wp:code {"language": "xml"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> <?xml version="1.0"?> <students> <student> <name>John</name> <grade>B</grade> <age>12</age> </student> <student> <name>Mary</name> <grade>A</grade> <age>11</age> </student> <student> <name>Simon</name> <grade>A</grade> <age>18</age> </student> </students>
Code language: Java (java)
Java code to parse above XML.
package net.viralpatel.java.xmlparser; import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class XMLParser { public void getAllUserNames(String fileName) { try { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = dbf.newDocumentBuilder(); File file = new File(fileName); if (file.exists()) { Document doc = db.parse(file); Element docEle = doc.getDocumentElement(); // Print root element of the document System.out.println("Root element of the document: " + docEle.getNodeName()); NodeList studentList = docEle.getElementsByTagName("student"); // Print total student elements in document System.out .println("Total students: " + studentList.getLength()); if (studentList != null && studentList.getLength() > 0) { for (int i = 0; i < studentList.getLength(); i++) { Node node = studentList.item(i); if (node.getNodeType() == Node.ELEMENT_NODE) { System.out .println("====================="); Element e = (Element) node; NodeList nodeList = e.getElementsByTagName("name"); System.out.println("Name: " + nodeList.item(0).getChildNodes().item(0) .getNodeValue()); nodeList = e.getElementsByTagName("grade"); System.out.println("Grade: " + nodeList.item(0).getChildNodes().item(0) .getNodeValue()); nodeList = e.getElementsByTagName("age"); System.out.println("Age: " + nodeList.item(0).getChildNodes().item(0) .getNodeValue()); } } } else { System.exit(1); } } } catch (Exception e) { System.out.println(e); } } public static void main(String[] args) { XMLParser parser = new XMLParser(); parser.getAllUserNames("c:\\test.xml"); } } [/code] <h2>17. Convert Array to Map in Java</h2> <!-- wp:code {"language": "java"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> import java.util.Map; import org.apache.commons.lang.ArrayUtils; public class Main { public static void main(String[] args) { String[][] countries = { { "United States", "New York" }, { "United Kingdom", "London" }, { "Netherland", "Amsterdam" }, { "Japan", "Tokyo" }, { "France", "Paris" } }; Map countryCapitals = ArrayUtils.toMap(countries); System.out.println("Capital of Japan is " + countryCapitals.get("Japan")); System.out.println("Capital of France is " + countryCapitals.get("France")); } }
Code language: Java (java)

18. Send Email using Java

import javax.mail.*; import javax.mail.internet.*; import java.util.*; public void postMail( String recipients[ ], String subject, String message , String from) throws MessagingException { boolean debug = false; //Set the host smtp address Properties props = new Properties(); props.put("mail.smtp.host", "smtp.example.com"); // create some properties and get the default Session Session session = Session.getDefaultInstance(props, null); session.setDebug(debug); // create a message Message msg = new MimeMessage(session); // set the from and to address InternetAddress addressFrom = new InternetAddress(from); msg.setFrom(addressFrom); InternetAddress[] addressTo = new InternetAddress[recipients.length]; for (int i = 0; i < recipients.length; i++) { addressTo[i] = new InternetAddress(recipients[i]); } msg.setRecipients(Message.RecipientType.TO, addressTo); // Optional : You can also set your custom headers in the Email if you Want msg.addHeader("MyHeaderName", "myHeaderValue"); // Setting the Subject and Content Type msg.setSubject(subject); msg.setContent(message, "text/plain"); Transport.send(msg); } [/code] <h2>19. Send HTTP request & fetching data using Java</h2> <!-- wp:code {"language": "java"} --><pre class="wp-block-code"><code></code></pre><!-- /wp:code --> import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.URL; public class Main { public static void main(String[] args) { try { URL my_url = new URL("http://www.viralpatel.net/"); BufferedReader br = new BufferedReader(new InputStreamReader(my_url.openStream())); String strTemp = ""; while(null != (strTemp = br.readLine())){ System.out.println(strTemp); } } catch (Exception ex) { ex.printStackTrace(); } } }
Code language: Java (java)

20. Resize an Array in Java

Code language: Java (java)
/** * Reallocates an array with a new size, and copies the contents * of the old array to the new array. * @param oldArray the old array, to be reallocated. * @param newSize the new array size. * @return A new array with the same contents. */ private static Object resizeArray (Object oldArray, int newSize) { int oldSize = java.lang.reflect.Array.getLength(oldArray); Class elementType = oldArray.getClass().getComponentType(); Object newArray = java.lang.reflect.Array.newInstance( elementType,newSize); int preserveLength = Math.min(oldSize,newSize); if (preserveLength > 0) System.arraycopy (oldArray,0,newArray,0,preserveLength); return newArray; } // Test routine for resizeArray(). public static void main (String[] args) { int[] a = {1,2,3}; a = (int[])resizeArray(a,5); a[3] = 4; a[4] = 5; for (int i=0; i
Get our Articles via Email. Enter your email address.

You may also like...


  1. Markus says:

    The singleton example is bad!

    As written, it won’t even compile, since singleInstance isn’t static.

    Secondly, unless you absolutely need lazy allocation and you can live with the singleton not being thread safe, you should change it to the much simpler and more robust:

    public class SimpleSingleton {  
        private static SimpleSingleton singleInstance = 
                                        new SimpleSingleton();  
        private SimpleSingleton() {  
        public static SimpleSingleton getInstance() {  
            return singleInstance;  

    • Holy Shit says:


    • edavreda says:

      Found you :)

    • Kristoff says:

      Lol Notch = FAG

  2. Dharmesh says:

    I had to appreciate.. Quick and very picky compilations of basic snippets, which probably you search around when you need it. But this comes handy, when you need it… thanks

  3. @markus: thanks for identifying the error. I have updated the code.

    @dharmesh: thanks for the comment. Feel free to bookmark the link and add it to any of your social site.

  4. Ralph says:

    According to the book Effective Java (http://java.sun.com/docs/books/effective/) from Joshua Bloch this is the best way to implement a singleton in Java 1.5 (or higher)

    public enum SimpleSingleton {
      public void doSomething() {  ....  }

    call the method from the singleton:


  5. Lukasz Zielinski says:

    You can have even nicer singleton using enum:

    public enum SimpleSingleton {  
         private SimpleSingleton() {  

  6. @ralph, @lukasz: Thanks for the better implementation of Singleton. Probably both of you have pointed to same implementation. I will add this to above post.

  7. Nice list of snippets. Very handy!

  8. Kenneth says:

    Thanks for those handy code snippet. Very useful for my daily work !

  9. Matt says:

    You can also do lazy singletons like this, I believe it is thread safe and backwards compatible before java 5:

    public SimpleSingleton {
      public static final SimpleSingleton INSTANCE = Inner.INSTANCE;
      private static class Inner {
        private static final SimpleSingleton INSTANCE = new SimpleSingleton();

  10. Matt says:

    *missed ‘class’ from the SimpleSingleton class above :/

  11. BDLH says:

    8. Create Thumbnail of an image in Java — this is ancient code.

    1. Use package javax.imageio to read and write images, not Toolkit, MediaTracker and JPEGCodec — I don’t think that was ever part of the official API, even!

    2. Your code with create a poor quality thumbnail. See Chris Campbell’s article for a better solution:


  12. I have an additional tip for ImageIO work. If you are reading lots of images for temporary use, be certain to disable ImageIO disk caching. I’ve published information about this technique here:


  13. Simon says:

    Please, correct me, if I’m wrong.
    I would change the second snippet:

    BufferedWriter out = null;
     try {  
         out = new BufferedWriter(new FileWriter("filename", true));  
     } catch (IOException e) {
         // error processing code
     } finally {
        if (out != null) {

    • sunita says:

      hello dear, kya ye sari scripts learn krni padhti h…. pls reply on my id

  14. @simone: thanks for changing the code. I have updated the main code.

  15. Jagadeesh says:

    Nice list of snippets. Saving our precious time to search for the things across the sites.Very handy.

  16. Igor says:

    More useful Java utilities:


  17. Is there any other way to convert array to Map without importing third party jar?

    Array to Set

    import java.util.*;
    public class ArrayToSet{
    public static void main(String arg[]){
    String elements[]={"array","to","set"};
    Set set=new HashSet(Arrays.asList(elements));
    	for (Iterator iterator = set.iterator(); iterator.hasNext();) {
                Object o = iterator.next();
                System.out.println(o );

  18. pradeep says:

    Hi Viral,

    Thank you for compilation of all usefull code snippets.

    But it will be more usefull if you can keep them in topics wise.

    I do want to look for more from your site.


  19. Arun says:

    Very Handy & Simple .

  20. Rekha says:

    Good post!! Nice and handy information.

  21. Thanks for the comment.
    I will try to compile more snippets for the developers.

  22. Trollhorn says:

    There is an even better solution for resizing an array:

    int[] a = new int[10];
    // roughly doubling the array size
    a = java.util.Arrays.copyOf(a, a.size * 2 + 1);

  23. Trollhorn says:

    Of course it should be a.length, sorry me :-)

    a = java.util.Arrays.copyOf(a, a.length * 2 + 1);

    A complete method would look similar to this:

    private static  void resizeArray(T[] a, int size) {
        if (size &lt; 0) {
            throw new IllegalArgumentException();
        return java.util.Arrays.copyOf(a, size);

  24. ali mohammad says:

    thank you sir these are very helping codes for me.

  25. Lingam Goud says:

    Thanks viral , it will helps a lot , hoping for more to come.

  26. Madhukar says:

    Tip 5, line # test.init(); —> will give a compile error. You need to pass the filestream to the init() function. Otherwise its a good example.

  27. Excellent site, keep up the good work

  28. Shubhangi says:

    I am searching for a code snippet that would convert a malformed XML string to a well formed one. Please let me know if any of you have it or a link to one such code snippet.

  29. great code collection.I specially liked XML parsing java code.

  30. begineer says:

    For Example there is a word (or) pdf (or) excel (or) PPT which has many pages .I need a java that will create a thumbnail for 1 page of those documents.
    Please let me know if Possible.
    Thanks in advance…

  31. Onon says:


    *Le gasp !

  32. anon says:

    Very nice collection, thank you.

  33. Subbiah says:

    any one tel use of xml file for dynamically storing data and retrieving data in Struts,spring and hibernate integration

  34. Mizan says:

    Hi Viral ,
    Can you provide a snippet for sending sms ?

  35. saharsh says:

    i have just started learning java can you tell me which is the best book for beginners and newbies
    please help

  36. lolailo says:

    java is so verbose

  37. Thank you very much.very handy.

  38. Peter says:

    I realize this is not a geography lesson, but I would like to point out that example 17 shows New York as the Capital of the United States. Washington D.C. is the Capital.

  39. Psion says:

    Your zip example doesn’t compress anything… You should be using


    instead of


  40. Hey.. real thanks for this article… too good and useful. I have some doubt in PDF Generation in Java using iText JAR. Could you tell me if I can have export to Excelsheet as well with all formatting in table. I need this to work with one of the Selenium projects.


  41. ankur chauhan says:

    Very nice tutorials….

  42. rajeswari says:

    how to fetch data from large excel files and update into database using jsp or servlet or jstl
    please help me sir………….

  43. Erik Malm says:

    JExcel offers excellent APIs for working with excel documents.
    Solves most of my reading and writing troubles, though this depends somewhat on the documents installed.

  44. Narayan says:

    Use this


    for moving/copy the files It’s really fast ,less code and new technology of Java as well.

  45. amit says:

    Kem cho bhai,

    Could I get library program (jar) to be used for small things such like change null to space or something. Im looking for such jar for servlet

  46. shekhar says:

    8. Create Thumbnail of an image in Java

    I got below error:but later i found the solution for that error that i mention below
    :Access restriction: The type JPEGImageEncoder is not accessible due to restriction on required library C:\Program Files\Java\jre7\lib\rt.jar

    so below is solution for that error:
    Go to the Build Path settings in the project properties.
    Remove the JRE System Library
    Add it back; Select “Add Library” and select the JRE System Library.
    That is perfect match

    Thats All and Enjoy the Code.

  47. can you tell me is this gona run in my eclipes??coz still have a problm..and showing me ‘RED’ COLOR ERROR..plzz..help me..
    java code here

    import java.io.File;
    import java.io.IOException;
    import java.util.List;
    import org.openqa.selenium.By;
    import org.openqa.selenium.WebDriver;
    import org.openqa.selenium.WebElement;
    import orlities;
    import org.openqa.selenium.support.ui.Select;
    import org.openqa.selenium.chrome.ChromeDriverService;
    import org.openqa.selenium.firefox.FirefoxDriver;
    import org.openqa.selenium.firefox.FirefoxProfile;
    import org.openqa.selenium.remote.DesiredCa
    pabiclass MyFirstAutomation {
      public static void main(String[] args) throws InterruptedException,
              IOException {
      public static void testVisaFlow() throws IOException {
               FirefoxProfile profile = new FirefoxProfile();
          DesiredCapabilities desiredCapabilities = DesiredCapabilities.firefox();
          desiredCapabilities.setCapability(FirefoxDriver.PROFILE, profile);
          WebDriver driver = new FirefoxDriver(desiredCapabilities);
          WebElement searchTextElement = driver.findElement(By
          searchTextElement.sendKeys("credit card");

    plzz.. or something i miss to add in jar,,coz its not running,,why//

  48. pawan says:

    Hi Friends,
    This is pawan. I need help regarding PAGINATION in java using struts.
    i am getting all records & count from DB, bt from jsp how i need to pass.. can any one explain or show me a sample of code which could be very helpful to me.

    First Previous {1 2 3 4 5} Next

    The o/p should be like this.

    Thanks in advance.
    Waiting for reply ASAP.

  49. Thanks used the snipper #7

  50. God bless you. These are tips people neglect but are very neccessary. Thanks man!

  51. sami says:

    hi viral,
    i want know how to read a finger print and convert that finger print into image using java,i need this for attendance process.
    i am using thumb reader digital persona u 4500
    thanks in advance…

  52. Rohit says:

    What an ambiguity!

    Your website is viralpatel(DOT)NET and you are giving snippets for JAVA. :D

    Just kidding, good work bro! :)

  53. Ananda says:

    Create Thumbnail of an image in Java..
    which jar you are using for this program..plz post the link for me

  54. Ferdaus says:

    Hello ,

    I want to know , which java code I need to add in my tag . Please give me the code .

  55. Ferdaus says:

    Hello ,
    I want to know , which java code I need to add in my head tag . Please give me the code .

  56. TuxGamer says:


    thanks for the code snippets.
    They helped me a lot! :)


  57. Vikram Hiraman Gore says:

    Hi Viral Patel ,
    I am doing a project . It requires to read “Marathi” PDF from java. I am using Aspose-pdf.jar but its not reading properly for complex characters . Like क्ष ,त्र ,ज्ञ etc . Is there any jar files which can read “Marathi” language PDF properly from Java .It requires on very urgent basis.

  58. Gagan says:

    I have gone through a blog according to which you have following options –

    For simple RGB files use ImageScalr . ImageIO class is used for reading files and ImageScalr to create thumbnails
    For supporting RGB + CYMK, use ImageIO and JAI (Java Advanced Imaging) API for reading files and ImageScalr to create thumbnail.
    In case you don’t know what file formats, color mode you are going to deal with, safest option is to use ImageMagick.
    Here is link http://paxcel.net/blog/java-thumbnail-generator-imagescalar-vs-imagemagic/

  59. Joe Jansen says:

    New York is not the capital of The United States. Washington DC is.

  60. Kyuseo Shim says:

    Thank you Viral.
    Your useful information have been helpful to me.

  61. kavali says:

    Hi Viral,
    How java .class files protect from Decompilation Process. is There any way is there Just give the suggestion. Please Don’t mention the obfuscator techniques like proguard and yguard. and encryption and decrytion

  62. Hi…. Viral…
    I Am Saving(Uploading) A File Like .Doc OR .Docx OR An Image In To Database(I Done This).
    Now I Want To Download That Particular File, So Can You Give The Code OR Can Guide Me About It That How I Can Download This File.
    I Am Using JSP,Servlet,My-SQL.

    Thank You
    Roshan Tailor

  63. ali says:

    nice tutorial thanks for sharing .

  64. javabelazy says:

    Nice posting. very much helpful for java trainees.

  65. Uday Kiran says:

    Is there any code to select some area of the screen and append that picture to a word document.

  66. jagruti says:

    I have image name in xml format and want to convert it in jpg.
    Please suggest.

  67. user says:

    Nice Stuff can u plz explain how to convert xml to json

  68. parth says:

    I have made one music catalogue system like gaana.com
    but one problem occured in my system , i can download perticular song but this song can’t play . error occured to play the songs any suggestion ?????????

    • parth says:

      after downloading they can’t play

  69. divakar says:

    i need java code for convert text data into xml format please send me the code

  70. ashish bansal says:

    Nice …. :-)

  71. Erik says:

    There is a compile error in 5. The method init(); in method main(..) actually expects a parameter ;-)

  72. N0din says:

    for singleton it is a best practice to store his instance in a holder, this make the singelton thread safe without the ugly need to use the ‘synchronized’ key word.
    public class Singleton {
    private static class SingletonHolder {
    private final static Singleton instance = new Singleton ();

    public static Singleton getInstance() {
    return SingletonHolder .instance;

  73. kantha says:

    hi, viral patel.
    will you please help me out ! , how to extract a paragraph from a text file and write the extracted paragraph to the html.

  74. Justin says:

    you skipped some numbers…

  75. Gokul Ahir says:

    Hi Viral,
    Pl. provide a way to download the tutorials in PDF format, if it is already exist then pl. share the details about how to down load the tutorial in the PDF format.

    Thanks and Regards,

  76. Dinesh says:

    Hi Viral,

    Thanks for sharing this post keep going.

  77. martina says:

    Very good site.

  78. wordbug says:

    java.util.Arrays.copyOf() resizes arrays, and it’s overloaded to work with primitives.

    From the javadoc:

    static T[] copyOf(T[] original, int newLength)
    Copies the specified array, truncating or padding with nulls (if necessary) so the copy has the specified length.

  79. Lohith says:

    Hi viral patel,

    Thanks for sharing this post. Very informative.


  80. Andreea says:

    Thanks a lot for sharing this code. I am using in my project the following snippet: 8. Create Thumbnail of an image in Java
    Could you please let me know which license applies for this code?

    • Hi Andreea, Feel free to copy the code.

Leave a Reply

Your email address will not be published. Required fields are marked *