public <T> List<T> subtract(List<T> list1, List<T> list2) {
		List<T> result = new ArrayList<T>();
		Set<T> set2 = new HashSet<T>(list2);
		for (T t1 : list1) {
			if( !set2.contains(t1) ) {
				result.add(t1);
			}
		}
		return result;
	}

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;

public class MacAddress {

    public static void main(String[] args) {
        try {
            //InetAddress address = InetAddress.getLocalHost();
            InetAddress address = InetAddress.getByName("192.168.46.53");

            /*
             * Get NetworkInterface for the current host and then read the
             * hardware address.
             */
            NetworkInterface ni = NetworkInterface.getByInetAddress(address);
            if (ni != null) {
                byte[] mac = ni.getHardwareAddress();
                if (mac != null) {
                    /*
                     * Extract each array of mac address and convert it to hexa with the
                     * following format 08-00-27-DC-4A-9E.
                     */
                    for (int i = 0; i < mac.length; i++) {
                        System.out.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : "");
                    }
                } else {
                    System.out.println("Address doesn't exist or is not accessible.");
                }
            } else {
                System.out.println("Network Interface for the specified address is not found.");
            }
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }
}

ServletContext ctx = (ServletContext) FacesContext.getCurrentInstance()
.getExternalContext().getContext();

After getting the servlet  context now we are able to get the real path

String deploymentDirectoryPath = ctx.getRealPath("/");

Quartz is a full-featured, open source job scheduling service that can be integrated with, or used along side virtually any Java EE or Java SE application – from the smallest stand-alone application to the largest e-commerce system. Quartz can be used to create simple or complex schedules for executing tens, hundreds, or even tens-of-thousands of jobs; jobs whose tasks are defined as standard Java components that are programmed to fulfill the requirements of your application. The Quartz Scheduler includes many enterprise-class features, such as JTA transactions and clustering.

CronTrigger

cron is a UNIX tool that has been around for a long time, so its scheduling capabilities are powerful and proven. The CronTrigger class is based on the scheduling capabilities of cron.

CronTrigger uses “cron expressions”, which are able to create firing schedules such as: “At 8:00am every Monday through Friday” or “At 1:30am every last Friday of the month”.

Cron expressions are powerful, but can be pretty confusing. This tutorial aims to take some of the mystery out of creating a cron expression, giving users a resource which they can visit before having to ask in a forum or mailing list.

Format

A cron expression is a string comprised of 6 or 7 fields separated by white space. Fields can contain any of the allowed values, along with various combinations of the allowed special characters for that field. The fields are as follows:

So cron expressions can be as simple as this: * * * * ? *
or more complex, like this: 0 0/5 14,18,3-39,52 ? JAN,MAR,SEP MON-FRI 2002-2010

Examples

Here are some full examples:

Special characters

• * (“all values”) – used to select all values within a field. For example, “*” in the minute field means “every minute”.

• ? (“no specific value”) – useful when you need to specify something in one of the two fields in which the character is allowed, but not the other. For example, if I want my trigger to fire on a particular day of the month (say, the 10th), but don’t care what day of the week that happens to be, I would put “10″ in the day-of-month field, and “?” in the day-of-week field. See the examples below for clarification.

• - – used to specify ranges. For example, “10-12″ in the hour field means “the hours 10, 11 and 12″.

• , – used to specify additional values. For example, “MON,WED,FRI” in the day-of-week field means “the days Monday, Wednesday, and Friday”.

• / – used to specify increments. For example, “0/15″ in the seconds field means “the seconds 0, 15, 30, and 45″. And “5/15″ in the seconds field means“the seconds 5, 20, 35, and 50″. You can also specify ‘/’ after the ‘‘ character – in this case ‘‘ is equivalent to having ’0′ before the ‘/’. ’1/3′ in the day-of-month field means “fire every 3 days starting on the first day of the month”.

• L (“last”) – has different meaning in each of the two fields in which it is allowed. For example, the value “L” in the day-of-month field means “the last day of the month” – day 31 for January, day 28 for February on non-leap years. If used in the day-of-week field by itself, it simply means “7″ or “SAT”. But if used in the day-of-week field after another value, it means “the last xxx day of the month” – for example “6L” means “the last friday of the month”. When using the ‘L’ option, it is important not to specify lists, or ranges of values, as you’ll get confusing results.

• W (“weekday”) – used to specify the weekday (Monday-Friday) nearest the given day. As an example, if you were to specify “15W” as the value for the day-of-month field, the meaning is: “the nearest weekday to the 15th of the month”. So if the 15th is a Saturday, the trigger will fire on Friday the 14th. If the 15th is a Sunday, the trigger will fire on Monday the 16th. If the 15th is a Tuesday, then it will fire on Tuesday the 15th. However if you specify “1W” as the value for day-of-month, and the 1st is a Saturday, the trigger will fire on Monday the 3rd, as it will not ‘jump’ over the boundary of a month’s days. The ‘W’ character can only be specified when the day-of-month is a single day, not a range or list of days.
• # – used to specify “the nth” XXX day of the month. For example, the value of “6#3″ in the day-of-week field means “the third Friday of the month” (day 6 = Friday and “#3″ = the 3rd one in the month). Other examples: “2#1″ = the first Monday of the month and “4#5″ = the fifth Wednesday of the month. Note that if you specify “#5″ and there is not 5 of the given day-of-week in the month, then no firing will occur that month.

Quartz Examples

Quartz Job Scheduler Tutorials

There can a be a various reasons for MySQL errno 150.
Following are the ways to verify your structure in order to fix your problem

1) type of foreign key source and reference fields must be identical
check: both set to integer

2) both source and reference fields must be unsigned
check: both fields are unsigned

3) source field must be indexed
check: id is indexed by idx

4) both tables must be InnoDB
check: both table InnoDB

Killing sessions can be very destructive if you kill the wrong session, so be very careful when identifying the session to be killed. If you kill a session belonging to a background process you will cause an instance crash.

Identify the offending session using the V$SESSION or GV$SESSION view as follows.

SELECT s.inst_id,
       s.sid,
       s.serial#,
       p.spid,
       s.username,
       s.program
FROM   gv$session s
       JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id
WHERE  s.type != 'BACKGROUND';

The SID and SERIAL# values of the relevant session can then be substituted into the commands in the following sections.

ALTER SYSTEM KILL SESSION

The basic syntax for killing a session is shown below.

ALTER SYSTEM KILL SESSION 'sid,serial#';

The KILL SESSION command doesn’t actually kill the session. It merely asks the session to kill itself. In some situations, like waiting for a reply from a remote database or rolling back transactions, the session will not kill itself immediately and will wait for the current operation to complete. In these cases the session will have a status of “marked for kill”. It will then be killed as soon as possible.

In addition to the syntax described above, you can add the IMMEDIATE clause.

ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;

This does not affect the work performed by the command, but it returns control back to the current session immediately, rather than waiting for confirmation of the kill.

Remove POST size limit

If we send large amount of data then Apache Tomcat must be configured to accept large amounts of data being sent to it, as the size of the data exceeds the default 2MB POST size limit.

To remove this limit, edit the /conf/server.xml file in the Tomcat home directory as follows:

• Find the tag entry for the HTTP 8080 connector
• Add the maxPostSize=”0″ attribute and value to this tag such that it looks like:

maxHttpHeaderSize="8192"
maxThreads="150"
minSpareThreads="25"
maxSpareThreads="75"
enableLookups="false"
redirectPort="8443"
acceptCount="100"
connectionTimeout="20000"
disableUploadTimeout="true"
maxPostSize="0" />

When you have completed editing the conf/server.xml file, save it and restart Apache Tomcat.

If the search for cool modules and functions on the Drupal site one thing you begin to see is the importance of modules that might not necessarily supply a prebuilt function, like a calendar for example, but provide the ability to define new types, views, or displays of data from either your Drupal site or a different source. The modules I’ve been exploring are:

• Feed Aggregator
• CCK
• Views
• Panels

Feed Aggreagtor is supplied in D6 and is pretty self explanatory. The remaining 3 are very powerful. I checked out the really cool myplay.com site Sony-BMG put together. If you haven’t seen it you should check it out. They made extensive use of Views and Panels to build this site. Views is in beta now for D6 and since I also wanted a calendar, I decided to start experimenting with Views. Ok – to explain that comment: the best Calendar function for D6 uses Views for the rendering of the event data. Because Views are still in beta I had to do some tweaking.

There are a bunch of overviews and tutorials for the original Views modules on drupal.org – so start there if you want an overview. What you’ll find however is that once you get past the “what is a view?” type stuff they aren’t much help. In short a View is a list of “stuff”. The list is defined in the Views administration area through a GUI interface. The list is generated by defining a query against your database – you add attributes to extract; arguments to select what to return; sorting criteria, etc. You can then select how to display the list: a node, a block, as a feed, etc. Pretty cool I think. How do you create one? That’s what I’ll cover.

To get started I’m working with the very latest Drupal code (6.2 at time of writing). I have a pretty basic config – but its completely to do date as of 3-May-2008. I’ve installed Views (6.x-2.0-beta2) and I’ve also installed the Advanced Help module (advanced_help-6.x-1.0-beta2).

To start with Views make sure you have the very latest by checking your adminstration area. Once you’ve done that then go into the page for administrating the Views module. You’ll see a few tabs for Adding and Importing views. Click on the Add choice and you should get a screen like this:

This is the main spot where you create your view. Go ahead and bang in some values and make sure you pick off the “node” choice. What we’re going to do is create a simple “node” type view that will look like a page. We can create a link in the Navigation menu for this afterwards.

Once you fill in some values then hit add and you’ll get this next screen. It looks pretty complicated, but just remember all you’re doing is defining a query.

Start with defining some fields to retrieve – just click on the plus sign. You’ll get an Ajax refresh that listed off the different groupings of fields. You should scroll around in here and see what’s available. Pick a few easy ones from the Node group like Author and Post date. As you pick fields you’ll see that Views is building the query for you and showing you example output:

As you move through the various items in the menu you can easily build some really cool output. The relationships block is used to define keys between fields. Arguments can be used to filter data based on a parameter, for example s returning records based on a date limiter.

After you get done playing around with the data you need to select a display view for your query results. There are several options, but for this example I’ve selected the page display mode. What this will be is create a view of the output in a “page” – gee imagine that. The output will display in the main content area.

The display view can either inherit from the base display or you can pick a new display mode and over ride the base settings with new fields or different sorting options or whatever. Just add a new display and then pick a setting – be sure to save things with the button down the page:

When doing this make sure to watch the button carefully as they are AJAX and change quickly. If you click something and you think nothing has happened, be sure to scroll down and look at the output.

Once you get done screwing around with your view you can then add it to a menu – for the page type just use the page settings. I added mine to my main menu. Experiment with the other display types.

That’s pretty much it. If you start to experiment with Views you can really learn to do some very interesting things. This is especially true for very active group/team sites where a lot of people are contributing content. One interesting things I’ve done with Views is assemble sorted “update” pages that show the latest contributions sorted by dates, or by users. This is a great way to keep up to date on what your teamates are doing.

• Components
• Documentation
• AJAX Integration
• Browser support
• Community
• Tool support (Eclipse, NetBeans)

It’s not possible for us to go through all the available frameworks one by one so for our ease http://www.jsfmatrix.net/ listed the features of all the available frameworks and their components.

]]> http://developerarticles.com/jsf-ajax-framework-matrix/feed/ 1