Ujjwal's Blog: jsp

Showing posts with label jsp. Show all posts

Tuesday, September 6, 2011

JSF code snippet: integrating JSF pages into a plain old JSP

A simple way to include a JSF page into a bigger JSP (sure there's other ways, but this one is easy):
the JSF page must be a subview:

<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<f:subview id="myJSFSubview">
.....
</f:subview>

The tricky part is how to include it in the JSP, in a way that is independent of the main JSP. But you just need to include like this:

<% pageContext.include("myJSFpage.jsf"); %>

Cheers,

Ujjwal Soni

Monday, June 15, 2009

IE6 Ajax Problem with included .js file

Hi All,

Recently i got to make a site that was to be used globally in different browsers, i made this site using jsp and other bunch of technologies and frameworks. The site also has to be compactible to all known browsers world wide including blackberry and safari for iphone. On during the development stage i found a very strange problem in internet explorer 6, i included a javascript file for ajax and created some of its instances in calling page javascript code, the browser behaved very strangely,

It sometimes was able to create an instance of that ajax object and sometimes was not able to create an instance. Well, in ie7 the code worked like a butter. I finally concluded of not using that included javascript code and directly using that function code in the calling jsp page.

Check out the below scenerio:

*********My ajax.js file
/*
This function returns XmlHttpRequest Object for ajax support
*/
function getXmlHttpObject(){

//identify the browser
if (window.XMLHttpRequest) {
//alert(" you are using IE7 or mozilla");
try{
// Firefox, Opera 8.0+, Safari
xmlHttp=new XMLHttpRequest();
if (xmlHttp.AJAX){
alert('firefox ajax support found');
}

}catch (e){
// Internet Explorer
var versions = ['Msxml2.XMLHTTP.7.0', 'Msxml2.XMLHTTP.6.0', 'Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP','Microsoft.XMLHTTP'];
for (var i = 0; i < versions.length ; i++){
try {
xmlHttp.AJAX = new ActiveXObject(versions[i]);
if (xmlHttp.AJAX){
alert('internet explorer ajax support found');
break;
}
}catch (objException) {}
}
}
return xmlHttp;

} else {
//alert(" you are using IE6");

try {
//alert("hello am in");
xmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
//alert("hello am out");

if (xmlHttp == null){
alert('internet explorer ajax support not found');
}
}catch (objException) {}
return xmlHttp;
}
}

****************My.jsp (The calling page)

function checkAjaxInIe()
{
var xmlHttp = getXmlHttpObject();
if (xmlHttp == null)
{
alert("Your browser does not support AJAX!");
return;
}

}

After implementing this scenerio, try running this code on ie6 with script debugger activated, if you run this code 100 times, you will get probability of the calling page creating instance of included js file only 50 times from 100 times.

To resolve this, i simply included the included file's ajax function in all my jsps.

Cheers!!!

Ujjwal B Soni

Sunday, April 12, 2009

how to detect usb device connected to system using java code

Hi Friends,

Here's d code..

import java.io.*;

/**
* Waits for USB devices to be plugged in/unplugged and outputs a message
*
*
*@author Ujjwal Soni
*@version 1.0, 16/04/2009
*/
public class FindDrive
{
/**
* Application Entry Point
*/
public static void main(String[] args)
{
String[] letters = new String[]{ "A", "B", "C", "D", "E", "F", "G", "H", "I"};
File[] drives = new File[letters.length];
boolean[] isDrive = new boolean[letters.length];

// init the file objects and the initial drive state
for ( int i = 0; i < letters.length; ++i )
{
drives[i] = new File(letters[i]+":/");

isDrive[i] = drives[i].canRead();
}

System.out.println("FindDrive: waiting for devices...");

// loop indefinitely
while(true)
{
// check each drive
for ( int i = 0; i < letters.length; ++i )
{
boolean pluggedIn = drives[i].canRead();

// if the state has changed output a message
if ( pluggedIn != isDrive[i] )
{
if ( pluggedIn )
System.out.println("Drive "+letters[i]+" has been plugged in");
else
System.out.println("Drive "+letters[i]+" has been unplugged");

isDrive[i] = pluggedIn;
}
}

// wait before looping
try { Thread.sleep(100); }
catch (InterruptedException e) { /* do nothing */ }

}
}
}