Log Levels on JBOSS Application server

There are 6 different log levels that can be configured in JBOSS Application server
A)FATAL
B)ERROR
C)WARN
D)INFO
E)DEBUG
F)TRACE

Oracle SQL Developer Data Modeling tool

The early adopter (EA) version of the Oracle SQL Developer Data Modeling tool is available for download on Oracle Technology Network. SQL Developer Data Modeling contains a complete set of graphical database modeling tools and utilities. It includes Entity Relationship modeling, Relational Database Design, Data Type and Multidimensional modeling, full forward and reverse engineering and code generation. This initial early adopter version is available as a standalone product, but future releases are planned to be available as an extension to Oracle SQL Developer.

http://www.oracle.com/technology/products/database/sql_developer/files/Modeling.html

Using HashSet

HashSet class is a concrete implementation of Set interface. It creates a collection that uses a hash table for storage. Hash table stores information by using a mechanism called hashing. In hashing, the informational content of a key is used to determine a unique value, called its hash code. The hash code is then used as an index at which the data associated with the key is stored. The transformation of key into its hash code is performed automatically. You never see the hash code itself. The advantage of hashing is that it allows the execution time of basic operation, such as add(), contains(), remove(), and size() to remain constant even for large sets.

HashSet is not synchronized. If more than one thread wants to access it at the same time then it must be synchronized externally.

source: java-tips.org

How to prevent your Pen Drive from Virus?

Many of your PC/laptop’s normally gets virus because of Pen Drives or USB devices (Even PC’s who are not connected to network). Some Virus like Ravmon Virus, Heap41a worm which are not detected by anti virus normally spreads mostly by the Pen Drives. In such a case what can you do to prevent your PC from getting infected with Virus that spreads through USB devices or Pen Drives?You can protect your PC by just following the simple steps below. It won’t take much time.
1. Connect your Pen Drive or USB drive to your computer.
2. Now a dialogue window will popup asking you to choose among the options as shown in the figure. Don’t choose any of them, just simply click Cancel.
3. Now go to Start > Run and type cmd to open the Command Prompt window .
4. Now go to My Computer and Check the Drive letter of your USB drive or Pen Drive. ( E.g. If it is written Kingston(I:) , then I: will be the drive letter.)
5. In the Command Window (cmd), type the drive letter: (e.g., I:) and Hit Enter.
6. Now type dir/w/o/a/p and Hit Enter.
7. You will get a list of files. In the list , search if anyone of the following do exists
* Autorun.inf
* New Folder.exe
* Bha.vbs
* Iexplore.vbs
* Info.exe
* New_Folder.exe
* Ravmon.exe
* RVHost.exe or any other files with .exe Extension.

• If you find any one of the files above, Run the command attrib -h -r -s -a *.* and Hit Enter.
• Now Delete each File using the following Command del filename ( E.g del autorun.inf ) .
• That’s it. Now just scan your USB drive with the anti virus you have to ensure that you made your Pen Drive free of Virus.
  

MVS SYSTEM CODES -S522

The wait time limit was exceeded for a job or job step.

1. The operator did not respond to a console request.
2. The program was waiting for a resource that was not available at execution time.
3. The CPU resource was not available at execution time.
4. The user request was invalid.

1. Check with the operator to determine if there were any outstanding requests for your job.
2. Check with the operator to determine if there were any problem jobs running at the same time as yours.

Ref: www.ibmmainframes.com

MVS SYSTEM CODES -S613

An error occurred in tape related input/output.

1. The JCL DD statement was incorrect.
2. An input/output error occurred in label processing.
3. The standard header labels were missing for an input data set.
4. There was a hardware malfunction.
An error occurred in tape positioning.
An error occurred in reading a tape label.
The tape label was invalid.
An error occurred in writing a tape label.
An error occurred in writing a tapemark after the header labels.

1. Verify that the JCL specifies the correct volume and device.
2. Verify that the volume contains standard labels.
3. Resubmit the job specifying a different volume or device

Ref: www.ibmmainframes.com

Using TreeSet

TreeSet stores objects in a sorted manner. TreeSet stores its elements in a tree and they are automatically arranged in a sorted order.
TreeSet is not synchronized. If more than one thread wants to access it at the same time then it must be synchronized externally.

import java.util.*;
public class DemoTreeSet {
public static void main(String[] args) {
TreeSet t1 = new TreeSet();
t1.add("ggg");
t1.add("aaa");
t1.add("ddd");
t1.add("bbb");
t1.add("nnn");
t1.add("lll");
System.out.println("Contents of treeset");
Iterator it1 =t1.iterator();
while(it1.hasNext()){
Object o1 = it1.next();
System.out.println(o1);
}
}
}

source: java-tips.org