Various ways of configuring Transaction in Spring

Declaration based

xml based : configure the transaction demarcation in the applicationContext.xml

a). Using AOP Tags

b). Using Interceptors

Annotation based:
The transaction demarcation are done in the Java code with specific tags.

Programmatic transaction

Here the Transaction activities are done in the code.

Wall Street Journal 2009 technology Awards

http://online.wsj.com/article/SB10001424052970203440104574399714096167656.html

Date Difference in MS SQL Server

There are cases where you need to quickly find the difference between 2 dates, you can use the following SQL Query:

SELECT DATEDIFF(ss, ‘2009-09-15 10:09:43.000′,’2009-09-15 10:10:07.000′ )

Removing blank lines in text file using Regular Expression

This tutorial explains about the removing blank lines using regular expression. Here I have used the TextPad Editor to do this.

For Example, the contents of the file is as follows , with lot of blank lines. We will see how we can remove this using TextPad

Select Search -> Replace or F8 (keyboard shortcut)

Select the option shown below, in the “Find what” field enter “^\n” (without the quotes), and then click on “Replace All” button.

This screenshot shows the final outcome of the text file.

Final Note:

What does the “^\n” mean ?

In regular expression “^” indicates the start of the line, “\n” is end of line,  so “^\n” is that any line starting new line character , replace with blank character.

Application Data Quality and Data Management

As the Application Evolves, which means adding new features, upgrades, fulfillment activities, new business process changes one of the biggest problem is Data Discrepancy between various heterogeneous data sources.

The Data Quality will start deteriorating as the system evolves, this needs to be addressed. A proper data management is required.

Some problems:
Clean up effort to large set of data will be difficult job.
This might increase lot of customer services calls. The company might turn into reactive mode of addressing customer issues.

Apache – RESTful Web services

Apache Wink provides framework for RESTful webservices.

http://incubator.apache.org/wink/

Download from the following location:

http://incubator.apache.org/wink/downloads.html

Java API for Cloud and Cloud Providers

Java API for Cloud

http://www.cloudloop.com/

http://dasein-cloud.sourceforge.net/

Cloud Providers

Amazon S3
Nirvanix
Eucalyptus Walrus
Rackspace CloudFiles
Sun Cloud
Microsoft Azure
EMC Atmos
Aspen
Diomede

Simple Sort Program in Java

Here is a simple sort program in Java. This program sorts the integer in an array.

package beam;

public class SimpleSort {

public void sortAndPrint(int[] iArr) {
/* define an array */
int[] iNerArr = new int[iArr.length];
int minItem = 0;
int minItemPos = -1;
int newItem = 0;
int iter=0;

for (int i = 0; i < iArr.length; i++) {
minItem = iArr[i];
minItemPos = -1;
for (int j = i; j < iArr.length; j++) {
newItem = iArr[j];
iter++;
/* if curritem gt newitem, interchange the values */
if (minItem > newItem) {
minItem = newItem;
minItemPos = j;

}
}

if (-1 != minItemPos) {
iArr[minItemPos] = iArr[i];
iArr[i] = minItem;
}

}

System.out.println(“total iterations ” + iter);
printArray(“after “, iArr);
}

/*method to print array. you can use what ever you want.*/
public void printArray(String str, int[] iArr) {
System.out.println(“————–(” + str + ” )—————–”);
System.out.print(“[");
for (int itemp = 0; itemp < iArr.length; itemp++) {
System.out.print(iArr[itemp] + “,”);
}
System.out.print(“]”);
System.out.println(“\n————–(” + str + ” )—————–”);
}

/**
* @param args
*/
public static void main(String[] args) {
SimpleSort ss = new SimpleSort();
int[] iArr = { 4, 5, 6, 2, 1 };
ss.printArray(“before”, iArr);
ss.sortAndPrint(iArr);

int[] iArr1 = { 2, 3, 4, 5, 6 };
ss.printArray(“before”, iArr1);
ss.sortAndPrint(iArr1);

int[] iArr2 = { -22, 1003, 2314, 1235, 132336 };
ss.printArray(“before”, iArr2);
ss.sortAndPrint(iArr2);

int[] iArr3 = { 1,2,4,3,2,1,6,3,2,4,3,5 };
ss.printArray(“before”, iArr3);
ss.sortAndPrint(iArr3);

}

}

Blog on Scalability / Storage solutions

Articles on Scalability / Storage solutions :

http://www.hfadeel.com/Blog/

Apache Lucene – First Tutorial

Download Lucene 2.4.1 , Extract to  c:\downloads

Copy the luceneweb.war to the <Tomcat Installation>/webapps folder.

Indexing files: The default location for the Lucene is /opt/lucene/index. Create a folder structure
manually on your windows/linux box

Windows:
c://opt/lucene/index

Create an create_index.bat , for convenience

set LUCENE_EXT=C:\downloads\lucene-2.4.1
set CLASSPATH=%CLASSPATH%;%LUCENE_EXT%\lucene-core-2.4.1.jar;%LUCENE_EXT%\lucene-demos-2.4.1.jar;
java org.apache.lucene.demo.IndexHTML -create  /opt/lucene/index

Results will be shown as below

C:\downloads\lucene-2.4.1>java org.apache.lucene.demo.IndexHTML -create  /opt/lucene/index
Optimizing index…
313 total milliseconds

Start the Tomcat

Accessing the luceneweb webapp

http://localhost/luceneweb

http://localhost:8080/luceneweb