Software Passion

Android Series: Parsing JSON data with GSON

admin — Thu, 25 Feb 2010 11:56:03 +0000

Today I will describe how to parse json data using Gson open source library and how to convert it at the same time to java objects.
This is a typical cookbook example and should be very easy to follow.
1. Create an Android application with one activity, name it as you wish, if you are doing it in eclipse all the basic stuff will be generated for you which is exactly what we need.
2. Find an example url which responds in JSON, I have used Twitter Trends found here: http://search.twitter.com/trends.json
The example response looks like this:

{"as_of":"Thu, 25 Feb 2010 11:30:17 +0000","trends":[{"name":"#nowplaying","url":"http://search.twitter.com/search?q=%23nowplaying"},{"name":"#nothingworsethan","url":"http://search.twitter.com/search?q=%23nothingworsethan"},{"name":"Dubai Mall","url":"http://search.twitter.com/search?q=%22Dubai+Mall%22"},{"name":"iPad Gets","url":"http://search.twitter.com/search?q=%22iPad+Gets%22"},{"name":"#SuperJuniorTrot","url":"http://search.twitter.com/search?q=%23SuperJuniorTrot"},{"name":"Justin Bieber","url":"http://search.twitter.com/search?q=%22Justin+Bieber%22"},{"name":"Click","url":"http://search.twitter.com/search?q=Click"},{"name":"Jaebum","url":"http://search.twitter.com/search?q=Jaebum"},{"name":"#tosavemoney","url":"http://search.twitter.com/search?q=%23tosavemoney"},{"name":"Protection","url":"http://search.twitter.com/search?q=Protection"}]}

As you can see this json data contains date attribute called ‘as_of’ as well as array of items, each consisting of name and url attributes.
We will create two simple java classes wich will hold that information.
First one is TwitterTrends.java

package com.softwarepassion.jsonexample;

import java.util.Date;

import java.util.List;

public class TwitterTrends {

    private String as_of;

    private List<TwitterTrend> trends;

    public String getAs_of() {

        return as_of;

    }

    public void setAs_of(String asOf) {

        as_of = asOf;

    }

    public List<TwitterTrend> getTrends() {

        return trends;

    }

    public void setTrends(List<TwitterTrend> trends) {

        this.trends = trends;

    }

}

And the second one is a simple TwitterTrend.java

package com.softwarepassion.jsonexample;

public class TwitterTrend {

    private String name;

    private String url;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getUrl() {

        return url;

    }

    public void setUrl(String url) {

        this.url = url;

    }

}

TwitterTrends contains a list of TwitterTrend objects, both of them are simple beans and are very similar to the json response if you look closely .

Now the fun part begins.

Download the Gson library from http://code.google.com/p/google-gson/ and add it to your java build path in eclipse.
Once you do that, you can now transform your json response to Java object on Android Platform:
Get the response as InputStream:

public InputStream getJSONData(String url){

        DefaultHttpClient httpClient = new DefaultHttpClient();

        URI uri;

        InputStream data = null;

        try {

            uri = new URI(url);

            HttpGet method = new HttpGet(uri);

            HttpResponse response = httpClient.execute(method);

            data = response.getEntity().getContent();

        } catch (Exception e) {

            e.printStackTrace();

        }

        return data;

    }

Then use that input stream to create your java objects:

public void runJSONParser(){

        try{

        Log.i("MY INFO", "Json Parser started..");

        Gson gson = new Gson();

        Reader r = new InputStreamReader(getJSONData("http://search.twitter.com/trends.json"));

        Log.i("MY INFO", r.toString());

        TwitterTrends objs = gson.fromJson(r, TwitterTrends.class);

        Log.i("MY INFO", ""+objs.getTrends().size());

        for(TwitterTrend tr : objs.getTrends()){

            Log.i("TRENDS", tr.getName() + " - " + tr.getUrl());

        }

        }catch(Exception ex){

            ex.printStackTrace();

        }

    }

Easy ha!

Apache Click on Google App Engine – Hello World Example

admin — Fri, 19 Feb 2010 10:44:47 +0000

Hello World!
If this blog would run on App Engine and was build with Apache Click I could finish this tutorial right here .
But more seriously, I will describe short step by step tutorial on how to get started with Apache Click on Google App Engine.
I’m assuming that you have GAE plugin for eclipse installed already as well as the latest libraries for Apache Click downloaded somewhere on your machine. (If not look at my previous post on how to get started with Apache Click on Eclipse Galileo (here).

If all is set up, lets get started..

1. Add new GAE type ‘Web Application Project’ (the one with blue google icon)

2. Copy click-2.1.0.jar and click-extras-2.1.0.jar to the lib directory under war/WEB-INF/lib of your GAE project.

3. Click on the project and select ‘Properties’ when you will modify the ‘Java Build Path’.

When changing the build path, select the two libraries you have added to you lib folder in point 2.

4. Delete the auto-generated GAE project stuff, like servlet and index.html files.
5. Create new class called ‘Index’

package com.softwarepassion.clickgae;

import java.util.Date;

import org.apache.click.Page;

public class Index extends Page{

    private Date time = new Date();

    public Index() {

        addModel("time", time); 

    }

}

Note the package you choose for you newly created class file, it will be needed when modifying config files later.

6. Create click.xml file in the same location where your web.xml file exists.
7. Modify your web.xml file to look similar to the one presented below:

 version="1.0" encoding="UTF-8"?>

 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

  >

         >org.apache.click.extras.gae.GoogleAppEngineListener>

  >

  >

    >ClickServlet>

    >org.apache.click.ClickServlet>

    >0>

  >

  >

    >ClickServlet>

    >*.htm>

  >

  >

    >index.htm>

  >

>

It looks like ordinary web.xml file with one important addition: the listener section.

8. Add content to your click.xml file:

 version="1.0" encoding="UTF-8" standalone="yes"?>

 charset="UTF-8">

  >

     path="index.htm" classname="com.softwarepassion.clickgae.Index">>

  >

   value="development"/>

>

9. Add index.htm file to the war directory

<html>

  <body>

    <h2>Hello World</h2>

    Hello world from Click at $time

  </body>

</html>

10. Deploy your app to Google App Engine and go to the url: http://yourappname.appspot.com

You should see very simple website with current time printed.

Getting started with Apache Click and Eclipse Galileo

admin — Thu, 18 Feb 2010 10:42:16 +0000

Last couple of days I read here and there about Apache Click, which is now in version 2.1.0. It looks preety cool and easy to learn, so I decided to give it a try and see for myself.
I understand that its cool to learn things using vi and shell only, but when you tried many frameworks before, you know how things works, you just want to see how or how not, productive you can be with the new framework, thats why I jump straight to the IDE.
And here, first surprise, with apache click its’ not that easy, well, I’m mean its still easy but I have encountered a few problems, and right now I would like to share the solution.
First of all, I did not tried all the examples in the apache click user guide yet, haven’t build anything usefull and definietly I’m not an Apache Click expert, I think I have figured out how to plug it to Eclipse and I think this is good start .

Here you have a few points to build your Apache Click IDE:
1. First of all download latest and greatest Eclipse Galileo from here – choose Eclipse for Java EE developers
2. Download Apache Click libraries from here – choose version 2.1.0
3. Download Apache Click IDE from here – note that it contains Click version 1.5 and it was last updated in November 2008 – maybe I’m missing something here?
4. Unzip your ClickIDE and copy the ‘features’ and ‘plugins’ folders into your Eclipse home directory
5. Unzip your latest click libraries and keep it for later
6. Start your Eclipse IDE and create new ‘Dynamic Web Project’

Choose target name, in this case ‘ClickDemo2′, select your target runtime as Tomcat 6+ etc.
7. Under configuration combo box, select custom and click ‘Modify’

8. Select ‘Click’ in Project Facet List and save the configuration as click config

9. Once you have your configuration created, dynamic web project screen should look like in the following screenshot:

10. The rest of the settings you can leave as it is, just click ‘Next’ up to the point when you finish creating new dynamic web project.
11. After your project is created it will have the structure like in the following screen:

Notice that there are click libraries from version 1.5, which is no good, we want to use the latest version which is 2.1.0.
12. Copy the files ‘click-2.1.0.jar’ and ‘click-extras-2.1.0.jar’ into the same lib folder where the old libraries are found.
13. Delete old libraries and refresh the project tree under eclipse (right click on the project node and select ‘Refresh’), now you will see the new libraries come up in the lib folder.
14. Open your web.xml file under ‘WebContent/WEB-INF/’ folder and change the class name of the main Click Servlet, from ‘net.sf.click.ClickServlet’ to ‘org.apache.click.ClickServlet’ in ’servlet-class’ declaration.
15. With Eclipse, select the project node and click ‘New’ -> ‘Other’, choose ‘Click Page’ under ‘click’ directory.

16. Fill out the necessary fields for your new click page as below:

17. Name the file ‘index.htm’ and click ‘Finish’
18. Under the page java source file, fix the Page class by using the page from the: org.apache.click.Page instead of the old path.

package com.softwarepassion;

import java.util.Date;

import org.apache.click.Page;

public class Index extends Page {

    private Date time = new Date();

    public Index(){

        addModel("time", time);

    }

}

Modify your ‘index.htm’ using html editor to look something like this:

<html>

  <head>

    <META HTTP-EQUIV="Content-Type" CONTENT="text/html;charset=UTF-8">

    <title>Blank</title>

    $imports

  </head>

  <body>

  $time

  </body>

</html>

19. Start up your project in tomcat. The page should display current time!

Additional Comments:
I know that this is just a quickfix, and I just cannot belive that there is no proper eclipse plugin using the latest click framework, which would be up to date, if you know any, than please comment and save me and my readers precious time.

Thank you.

Jasperberry – the most dynamic reports ever.

admin — Wed, 17 Feb 2010 09:03:08 +0000

Today I will describe in short my latest and simplest quick and dirty trick, generating jasper report dynamically. Jasperberry is a component written very quickly to help me
generate pdf report in a situation where I don’t know the number of columns I will have, I don’t know their widths, the data they contain etc, all is generated at runtime dynamically.
I know that there is DynamicJasper project but it seems to be dead, and its dead in a very strange way, I mean, I see that the authors commit new code but there is no chance to get any support unless, I guess, you pay for it.
With dynamic jasper I couldn’t generate report with polish fonts displayed properly, tried many different tricks, no support on the forum, no support on stack overflow, no nothing. After 2 days I have realized that I will write my own library quicker to solve my problem than get an answer from the dynamic jasper community (if there is any).
So here we have: jasperberry!

Don’t expect too much from it but if you want to display simple table with data, dynamic columns, adjustable fonts and colors than this is it.

In fact you don’t have to even know object properties to generate the report, we will use Apache DynaBeans for that:

This is a simple example code snipped showing you how to get started with the simplest and most dynamic reporting library ever (as well as lacking features probably but we hope its enough for simple projects)

This example assumes the following:

1. You want simple report
2. You dont have to know the object which properties you want to display in advance, by this I mean you can create report columns dynamically, and by using apache dyna beans your objects don’t have to even exists. You just dynamically create them and inject them into the report.

Here is an example test class showing you how to use jasperberry, for more info please contact us directly at softberries.com
Code:

public class JRXMLBuilderTest {

    private static List<JBColumnBean> columns;

    public JRXMLBuilderTest() {

    }

    @BeforeClass

    public static void setUpClass() throws Exception {

        columns = new ArrayList<JBColumnBean>();

        JBColumnBean col1 = new JBColumnBean();

        JBColumnBean col2 = new JBColumnBean();

        JBColumnBean col3 = new JBColumnBean();

        JBColumnBean col4 = new JBColumnBean();

        JBColumnBean col5 = new JBColumnBean();

        JBColumnBean col6 = new JBColumnBean();

        JBColumnBean col7 = new JBColumnBean();

        col1.setPreferredWidth(60);

        col1.setProperty("name");

        col1.setTitle("Imię");

        col2.setPreferredWidth(60);

        col2.setProperty("surname");

        col2.setTitle("Nazwisko");

        col3.setPreferredWidth(160);

        col3.setProperty("comment");

        col3.setTitle("Komentarz");

        col4.setPreferredWidth(100);

        col4.setProperty("comment2");

        col4.setTitle("Komentarz");

        col5.setPreferredWidth(100);

        col5.setProperty("comment3");

        col5.setTitle("Komentarz");

        col6.setPreferredWidth(100);

        col6.setProperty("comment4");

        col6.setTitle("Komentarz");

        col7.setPreferredWidth(100);

        col7.setProperty("comment5");

        col7.setTitle("Komentarz");

        columns.add(col1);

        columns.add(col2);

        columns.add(col3);

        columns.add(col4);

        columns.add(col5);

        columns.add(col6);

        columns.add(col7);

    }

    @AfterClass

    public static void tearDownClass() throws Exception {

    }

    @Before

    public void setUp() {

    }

    @After

    public void tearDown() {

    }

    /** * Test of build method, of class JRXMLBuilder. */

    @Test

    public void testBuild() {

        try {

            System.out.println("build");

            List<JBReportElement> elements = new ArrayList<JBReportElement>();

            //col header font 

            JBFont colHeaderFont = new JBFont();

            colHeaderFont.setBold(true);

            colHeaderFont.setSize(10);

            colHeaderFont.setForegroundColor("#555555");

            //detail font 

            JBFont detailFont = new JBFont();

            detailFont.setSize(6);

            detailFont.setForegroundColor("#000000");

            detailFont.setPdfEncoding("Cp1257");

            JBPage page = new JBPage();

            JBReport report = new JBReport(page, colHeaderFont, detailFont, "#CCCCFF", "#DEDEDE", "#FFFFFF");

            JBFont titleFont = new JBFont();

            titleFont.setBold(true);

            titleFont.setSize(20);

            titleFont.setForegroundColor("#FF0000");

            titleFont.setPdfEncoding("Cp1257");

            //add title elements 

            elements.add(new JBStaticTextElement("Hello World!", 450, 10, 300, titleFont));

            elements.add(new JBImageElement("C:\\\\Documents and Settings\\\\admin\\\\Moje dokumenty\\\\NetBeansProjects\\\\JASPER_BERRY\\\\test.jpg", 0, 0, 350, 242));

            report.setTitleElements(elements);

            JRXMLBuilder instance = new JRXMLBuilder(columns, report);

            boolean expResult = true;

            boolean result = instance.build();

            JasperReport jr = JasperCompileManager.compileReport("jasperberry_by_softberries.jrxml");

            //PREPARE SOME DATA 

            DynaProperty[] props = new DynaProperty[columns.size()];

            for (int i = 0; i < columns.size(); i++) {

                props[i] = new DynaProperty(columns.get(i).getProperty(), String.class);

            }

            BasicDynaClass dynaClass = new BasicDynaClass("tester", null, props);

            List<DynaBean> beans = new ArrayList<DynaBean>();

            for (int i = 0; i < 100; i++) {

                DynaBean db = dynaClass.newInstance();

                db.set("name", "Krzysztof " + i);

                db.set("surname", "Grajek " + i);

                db.set("comment", "Komentarz ");

                db.set("comment2", "Komentarz ");

                db.set("comment3", "Komentarz ");

                db.set("comment4", "Komentarz ");

                //

                db.set("comment5", "Komentarz ");

                beans.add(db);

            }

            JasperPrint jp = JasperFillManager.fillReport(jr, null, new JRBeanCollectionDataSource(beans));

            JasperExportManager.exportReportToPdfFile(jp, "jasperberry.pdf");

            assertEquals(expResult, result);

        } catch (Exception ex) {

            Logger.getLogger(JRXMLBuilderTest.class.getName()).log(Level.SEVERE, null, ex);

        }

    }

}

You should find similar snippet in a test suite of the project.
The project itself is licensed under LGPL and its available from sourceforge here

Deploy your Java Application with IzPack Installer

admin — Sat, 06 Feb 2010 18:16:36 +0000

This is a short tutorial on how to create simple IzPack based installation solution on windows platform with all standard features like: desktop shortcut, start menu item shortcut, copying libraries, folders, documentation into one of the ProgramFiles folder on the windows machine.
I had some problems creating windows shortcuts mysefl and I wanted to share the experience so other people can find it quicker.
Here you go.

1. First download and install IzPack itself from: izpack website

2. Prepare the application you want to make installable, I use Netbeans to build most of my Java apps, but I guess for all other ide’s the results after all are the same, we end up with SomeApp.jar file and a bunch of libraries we used to build it.
On the Netbeans platform all the files needed to launch the application we have build end up in ‘dist’ folder as a subfolder of our project main folder. If you have used any libraries to build your desktop application they will be included in the lib folder (yourproject/dist/lib/).

3. Now, once we have all the main ingredients (our application and installer) we need to connect it together. Create the folder anywhere on your machine, and call it for example ’softwarepassion’.

4. Put your jar file together with the ‘lib’ folder into the ’softwarepassion’ catalog.

5. Now we need to add some native libraries for Izpack to be able to add windows shortcuts on the desktop and start menu. Create ‘bin’ folder under the ’softwarepassion’ folder and copy whole ‘native’ content found in your izpack installation into the ‘bin’ folder of your root ’softwarepassion’ catalog.
You can find the native folder inside your IzPack installation directory, normally under: ‘C:\Program Files\IzPack\bin’

6. Create your application icon file and add it to your ’softwarepasison’ catalog. I call mine ‘exe.ico’.

7. Now comes the hardest part to get initially but after you build your first installer it all gets clear and easy
We need to prepare two separate xml files: one called ‘install.xml’ and another one called ’shortcutSpec.xml’.

The content of both example files is listed below:

 version="1.0" encoding="iso-8859-1" standalone="yes" ?>

 version="1.0">

    >

        >SoftwarePassion Application>

        >1.0>

        >

             name="Softberries Krzysztof Grajek" email="customer.service@softberries.com"/>

        >

        >http://www.softwarepassion.com/>

    >

     width="640" height="480" resizable="yes"/>

    >

         name="DesktopShortcutCheckboxEnabled" value="true"/>

    >

    >

         iso3="pol"/>

         iso3="eng"/>

    >

    >

         src="shortcutSpec.xml" id="shortcutSpec.xml"/>

         id="LicencePanel.licence" src="Licence.txt"/>

         id="InfoPanel.info" src="Readme.txt"/>

    >

    >

         classname="HelloPanel"/>

         classname="LicencePanel"/>

         classname="TargetPanel"/>

         classname="PacksPanel"/>

         classname="InstallPanel"/>

         classname="ShortcutPanel"/>

         classname="FinishPanel"/>

    >

    >

         name="Base" required="yes">

            >The base files>

             src="Readme.txt" targetdir="$INSTALL_PATH"/>

             src="Licence.txt" targetdir="$INSTALL_PATH"/>

             src="exe.ico" targetdir="$INSTALL_PATH"/>

             src="SoftwarePassionHelloIzPack.jar" targetdir="$INSTALL_PATH"/>

             dir="lib" targetdir="$INSTALL_PATH\lib">

                 name="**"/>

            >

        >

    >

     type="izpack" name="ShellLink.dll"/>

     type="3rdparty" name="COIOSHelper.dll" stage="both">

         family="windows"/>

    >

>

And the one for windows shortcuts:

 version="1.0" encoding="UTF-8" standalone="yes" ?>

>

    />

     defaultName="Siemens AWORT" location="applications"/>

         name="SoftwarePassion Application"

         programGroup="yes"

         desktop="yes"

         applications="no"

         startMenu="yes"

         startup="no"

         target="$INSTALL_PATH\SoftwarePassionHelloIzPack.jar"

         commandLine=""

         description="Software Passion Example App"

         iconFile="$INSTALL_PATH\exe.ico"

         iconIndex="0"

         initialState="noShow">

          name="Base"/>

       >

            name="Software Passion Example App Uninstaller"

            programGroup="yes"

            desktop="no"

            applications="no"

            startMenu="no"

            startup="no"

            target="$INSTALL_PATH\Uninstaller\uninstaller.jar"

            commandLine=""

            iconFile="%SystemRoot%\system32\SHELL32.dll"

            iconIndex="31"

            description="Uninstall SoftwarePassion Example">

         name="Base"/>

    >

>

8. Example installation script contains both Readme.txt and Licence.txt which you can add to your ’softwarepassion’ folder.
9. Once you have it all in one place, you should have a structure like in the following screenshot:

10. Now assuming that your ’softwarepassion’ folder has been placed directly on the c: drive, execute the following command:

C:\Program Files\IzPack\bin>compile c:\softwarepassion\install.xml -b c:\softwarepassion

Assuming that IzPack itself was installed at: C:\Program Files\IzPack

This will produce install.jar file which is your installer.

11. If you dont’ want your end users to click on the ‘jar’ file as not everybody knows they can do that, you can add Izpack launcher app which will launch it automatically, or use another tool to create an executable called launch4j

You have to admit that it was an easy one!!!!!

Happy Installing!

Download example files from here

Add ‘count #’ column to JTable

admin — Fri, 05 Feb 2010 14:18:52 +0000

Important note first: This is mostly not my code, I was strugling with this problem for some time, I couldn’t google it at all, and one day, I’ve just found it. Now I use it in one of my projects but I cannot find the original post again, therefore I have decided to post it on my blog (slightly modified version of the original) so other people with similar problem will have a better chance of finding the solution.
So, the idea is very simple. The whole point of displaying additional column which is kind of independent from the other columns is to simply use another table. This way you can sort one table by column and the number column will not sort with it. – thats exactly what I was looking for and I guess its kind of popular problem.
Becouse you put two tables in one scroll pane the gui looks like its just one column!

I have created one simple method to apply this technique to any tables in my application (I use JXTable actually but JTable will do as well)

private void addLPColumn(JXTable table, JScrollPane scp){

        JTable rowTable = new RowNumberTable(table);

        scp.setRowHeaderView(rowTable);

        scp.setCorner(JScrollPane.UPPER_LEFT_CORNER, rowTable.getTableHeader());

        scp.repaint();

    }

RowNumberTable is simple one column table displaying the ‘count’ number of rows in the second table.

public class RowNumberTable extends JTable

    implements ChangeListener, PropertyChangeListener

{

    private JTable main;

    public RowNumberTable(JTable table)

    {

        main = table;

        main.addPropertyChangeListener( this );

        setFocusable( false );

        setAutoCreateColumnsFromModel( false );

        setModel( main.getModel() );

        setSelectionModel( main.getSelectionModel() );

        TableColumn column = new TableColumn();

        column.setHeaderValue("Lp.");

        addColumn( column );

        column.setCellRenderer(new RowNumberRenderer());

        getColumnModel().getColumn(0).setPreferredWidth(40);

        setPreferredScrollableViewportSize(getPreferredSize());

    }

    @Override

    public void addNotify()

    {

        super.addNotify();

        Component c = getParent();

        //  Keep scrolling of the row table in sync with the main table.

        if (c instanceof JViewport)

        {

            JViewport viewport = (JViewport)c;

            viewport.addChangeListener( this );

        }

    }

    /*

     *  Delegate method to main table

     */

    @Override

    public int getRowCount()

    {

            if(main != null)

                return main.getRowCount();

            else

                return 0;

    }

    @Override

    public int getRowHeight(int row)

    {

        return main.getRowHeight(row);

    }

    /*

     *  This table does not use any data from the main TableModel,

     *  so just return a value based on the row parameter.

     */

    @Override

    public Object getValueAt(int row, int column)

    {

        return Integer.toString(row + 1);

    }

    /*

     *  Don't edit data in the main TableModel by mistake

     */

    @Override

    public boolean isCellEditable(int row, int column)

    {

        return false;

    }

//

//  Implement the ChangeListener

//

    public void stateChanged(ChangeEvent e)

    {

        //  Keep the scrolling of the row table in sync with main table

        JViewport viewport = (JViewport) e.getSource();

        JScrollPane scrollPane = (JScrollPane)viewport.getParent();

        scrollPane.getVerticalScrollBar().setValue(viewport.getViewPosition().y);

    }

//

//  Implement the PropertyChangeListener

//

    public void propertyChange(PropertyChangeEvent e)

    {

        //  Keep the row table in sync with the main table

        if ("selectionModel".equals(e.getPropertyName()))

        {

            setSelectionModel( main.getSelectionModel() );

        }

        if ("model".equals(e.getPropertyName()))

        {

            setModel( main.getModel() );

        }

    }

    /*

     *  Borrow the renderer from JDK1.4.2 table header

     */

    private static class RowNumberRenderer extends DefaultTableCellRenderer

    {

        public RowNumberRenderer()

        {

            setHorizontalAlignment(JLabel.CENTER);

        }

        public Component getTableCellRendererComponent(

            JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)

        {

            if (table != null)

            {

                JTableHeader header = table.getTableHeader();

                if (header != null)

                {

                    setForeground(header.getForeground());

                    setBackground(header.getBackground());

                    setFont(header.getFont());

                }

            }

            if (isSelected)

            {

                setFont( getFont().deriveFont(Font.BOLD) );

            }

            setText((value == null) ? "" : value.toString());

            setBorder(UIManager.getBorder("TableHeader.cellBorder"));

            return this;

        }

    }

}

In my case the ‘count’ column is called ‘Lp.’ – in polish

I have created one simple method to apply this technique to any tables in my application (I use JXTable actually but JTable will do as well)

private void addLPColumn(JXTable table, JScrollPane scp){

        JTable rowTable = new RowNumberTable(table);

        scp.setRowHeaderView(rowTable);

        scp.setCorner(JScrollPane.UPPER_LEFT_CORNER, rowTable.getTableHeader());

        scp.repaint();

    }

JXTable and primary key – how to.

admin — Mon, 07 Dec 2009 11:42:47 +0000

Today I will describe in a few words and a couple lines of code how to get the id of the row in JXTable. When working with data coming from database we don’t really want to display the primary key of the object but to hide it. This can cause a small problem once we want to find out for example which item was clicked, ok we can easily find out which row it was but its not always easy to find out which actual object it was especially when using JXTable sorting capabilities.
The whole trick is to get the the corresponding object from the model and not from the view.
Here is a short code snippet to do just that, hope that helps everyone who uses great JXTable component to display some data.

private int getObjectID(JXTable table) {

        int rowx = table.getSelectedRow();

        int resultx = 0;

        if (rowx < 0) {

            return 0;

        }

        resultx = table.convertRowIndexToModel(rowx);

        int id = (Integer) table.getModel().getValueAt(resultx, 0);

        return id;

    }

This works of course assuming that your object index is set as first column in your model (position 0).

Small Web Design Inspiration Set

admin — Tue, 01 Dec 2009 17:09:20 +0000

This is a small set of links I’ve found pointing to some collections of web page screenshots which you can use for your web design inspiration. I have found it very usefull and I hope you will find it usefull too. If you know some more which are not listed here please share using comments section.

Have fun!

15+22 jQuery Image Slideshow/Slider Tutorials and Plugins for Your Next Projects

admin — Tue, 01 Dec 2009 16:45:12 +0000

15+22 jQuery Image Slideshow/Slider Tutorials and Plugins for Your Next Projects

Top 10 Things to Know About Amazon RDS

admin — Sun, 22 Nov 2009 12:56:08 +0000

Top 10 Things to Know About Amazon RDS

Top 10 Things to Know About Amazon RDS