For 99.999%

tag:blogger.com,1999:blog-24709165356363234582011-09-13T16:33:17.748+05:30For 99.999%Learning HArkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.comBlogger221100tag:blogger.com,1999:blog-2470916535636323458.post-55979269411031559752010-11-20T17:18:00.001+05:302010-11-20T17:18:25.647+05:30What is Struts ?

What is Struts ?Apache Struts is a free open-source framework for creating Java web applications.Difference Between Struts 1 and Struts 2 Struts1 was an action- oriented framework that implemented a Model-View-Controller (MVC) separation of concerns in its architecture. Struts2 is a brand new implementation of those same MVC principles in an action-oriented framework. Difference Between Struts 1

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-67190348439576062732010-11-20T17:14:00.001+05:302010-11-20T17:14:18.544+05:30Differences Between Struts 1 and Struts 2

Base Action class is abstract class in Struts1 where as it is Interface in Struts2 and also provides a base ActionSupport class that implements commonly used interfaces. Struts 1 Actions are singletons and must be thread-safe where as Struts 2 doesn't have thread-safety issues as Action objects are instantiated for each request. Actions are dependent on the servlet API , as HttpServletRequest

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-56859418198700200202010-09-02T20:02:00.001+05:302010-09-03T12:55:19.349+05:30Java Annotations Introduction

AnnotationsAnnotations provide data about a program that is not part of the program itself. They have no direct effect on the operation of the code they annotate. Annotations have a number of uses, among them: Information for the compiler — Annotations can be used by the compiler to detect errors or suppress warnings. Compiler-time and deployment-time processing — Software tools can

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-28346893016241827252010-08-27T15:26:00.000+05:302010-08-27T15:27:01.256+05:30Java Command-line flags for the JVM

DisableExplicitGC-XX:+DisableExplicitGC flag automatically turns a System.gc() call into a no-op HeapDumpOnOutOfMemoryError -XX:+HeapDumpOnOutOfMemory Setting this command tells the JVM to take a "heap dump snapshot" and save it to a file for processing. You can specify the actual path to which the file is saved using the corresponding -XX:HeapDumpPath flag.java -X lists all the non-standard (

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-85821712227693295592010-08-27T14:59:00.001+05:302010-08-27T14:59:28.034+05:30MySQL Joins

Mysql Inner Join returns the set of only those records which matches in one table with another.If I do a regular JOIN (with none of the keywords INNER, OUTER, LEFT or RIGHT), then I get all records that match in the appropriate way in the two tables, and records in both incoming tables that do not match are not reported:mysql> select name, phone, selling from demo_people join demo_property

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-91380295015932054392010-08-24T13:21:00.001+05:302010-08-24T13:21:47.930+05:30Spring aware interfaces

For the most part, beans running in the Spring container, They don't know (or even need to know) their names or even that they are running within a Spring container. This is usually a good thing because if a bean is aware of the container, then it becomes coupled with Spring and may not be able to exist outside of the container. A well designed component should not have direct dependencies on

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-91061032038762430552010-08-18T18:52:00.002+05:302010-09-03T12:59:38.748+05:30UDH in Binary SMS / Multipart SMS messsages

Multipart SMS messaging By design, SMS is developed to send up to 140 bytes of user data. All user data is send in the 'User Data' part of the SMS packet. Because SMS text messages are encoded using 7-bit characters you can send up to 160 characters in a single SMS message. When sending Unicode text, you can only send 70 characters per single SMS message. It is however possible to split up text

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-44902084603588813002010-07-12T15:38:00.001+05:302010-07-12T15:38:37.355+05:30JAVA Composition vs Aggregation

Association - it's a structural relationship between two classifiers i.e. classes or Use cases.An Association specifies how objects are related to one another. Aggegation & Composition are associations with following qualities. Aggegation is normally understood as a "has-a" relationship. Here both the entities continue to have their own independent existence. Aggregations are not allowed to be

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-64074949708707847842010-06-15T19:35:00.001+05:302010-06-15T19:37:05.123+05:30Why we need MVC framework?

Why we need MVC framework? Web applications differ from conventional websites in that web applications can create a dynamic response. Many websites deliver only static pages. A web application can interact with databases and business logic engines to customize a response. Web applications based on JavaServer Pages sometimes commingle database code, page design code, and control flow code. In

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-84988913110396784792010-04-13T12:49:00.003+05:302010-04-13T12:52:37.092+05:30Formatting(Precision) Java Double /Float Decimal Digits

Formatting( Precision ) Java Double Decimal Digits Formatters converts a floating point/double value to a string with a specified number of decimals. For formatting the decimal part of double/Float we can use NumberFormat or DecimalFormat . The difference between them is that NumberFormat is an abstract class. DecimalFormat is a concrete implementation of NumberFormat. Using

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-17819828499643496252010-02-18T14:42:00.001+05:302010-02-18T14:50:53.611+05:30Parameter retrieval from JSP with multipart/form-data

javax.servlet.HttpServletRequest.getParameter(String) returns null when the ContentType is multipart/form-data Solution A: invoke getParameters() on com.oreilly.servlet.MultipartRequest You can get files from here Solution B: 1. download Jar file from here 2. invoke readHeaders() in org.apache.commons.fileupload.MultipartStream JSP Example program here Solution C: invoke getParameter

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-69258207490993465692010-01-29T18:39:00.006+05:302010-01-29T18:53:22.518+05:30Comparison of Java ==, .equals(), compareTo(), and compare()

Source & Full Article When you really need to know if two references are identical, use ==. But when you need to know if the objects themselves (not the references) are equal, use the equals() method. If you don't override a class's equals() method, you won't be able to use those objects as a key in a hashtable and you probably won't get accurate Sets, such that there are no conceptual

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-20048940945375698302010-01-21T19:49:00.005+05:302010-01-21T20:07:37.656+05:30Java 2 Platform, Enterprise Edition (J2EE) FAQ

What is the Java 2 Platform, Enterprise Edition (J2EE)? The Java 2 Platform, Enterprise Edition (J2EE) is a set of coordinated specifications and practices that together enable solutions for developing, deploying, and managing multi-tier server-centric applications. Building on the Java 2 Platform, Standard Edition (J2SE), the J2EE platform adds the capabilities necessary to provide a complete,

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-25055321826118653442010-01-18T19:49:00.001+05:302010-01-21T20:05:17.329+05:30Definitions of JRE JDK JVM J2SE J2EE

Java SE Overview There are two principal products in the Java SE platform family: Java SE Runtime Environment (JRE) and Java Development Kit (JDK). Java Runtime Environment (JRE) The Java Runtime Environment (JRE) provides the libraries, the Java Virtual Machine, and other components to run applets and applications written in the Java programming language. In addition, two key deployment

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-69094489332733410582009-12-24T20:50:00.005+05:302009-12-24T20:59:59.504+05:30Java’s String pooling

A string pool is a collection of references to String objects. Strings, even though they are immutable, are still objects like any other in Java. Objects are created on theheap and Strings are no exception. So, Strings that are part of the "String Literal Pool" still live on the heap, but they have references to them from the String Literal Pool. When a .java file is compiled into a .class

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-28352947820982275442009-12-22T19:47:00.004+05:302010-09-03T13:02:05.790+05:30Inversion of Control ( IOC ) Design pattern

Inversion of Control (IoC) design pattern BasicsThe Inversion of Control (IoC) pattern is also known as Dependency Injection. The basic concept of the Inversion of Control pattern is that programmers don’t need to create the objects but describe how they should be created.IOC design pattern alleviates application objects from the responsibility of creating, and managing their dependencies.

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-87919539522845001412009-11-27T19:27:00.000+05:302009-11-27T19:30:02.740+05:30Servlet Container & Request processing

Why we need Container for Servlets? Servlets don't have main() method,They run under control of another java application called container. Ex: Tomcat When Server gets request for servlet the server handovers the request to container in which Servlet is deployed. In simple "Container manages and runs the Servlet". Advantages of using Container: Communication The container

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-25838621631601941712009-11-19T19:10:00.001+05:302009-11-23T14:34:44.110+05:30Creating jasper reports in 4 simple steps

Download the jasper reports Lib and Source from here. Intro: JasperReports is an open-source Java class library designed to aid developers with the task of adding reporting capabilities to Java applications. JasperReports is licensed under the Lesser GNU Public License (LGPL). Features: It has flexible report layout. It is capable of presenting data textually or

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-16647936243990074732009-11-11T13:22:00.000+05:302009-11-11T13:23:00.205+05:30MySQL monitoring Using ' mycheckpoint '

Download the packge from here . Dependencies yum install MySQL-python. Installation untar the file and run follwoing commands tar xzfv mycheckpoint-XXX.tar.gz cd mycheckpoint-XXX sudo python setup.py install Run follwing commads on mysql prompt CREATE DATABASE mycheckpoint; GRANT ALL PRIVILEGES ON mycheckpoint.* TO

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-88569487926184407352009-11-10T13:32:00.000+05:302009-11-10T13:32:47.313+05:30Configuration of MySQL network related variables

max_connect_errors connect_timeout skip-name-resolve slave_net_timeout For more details ...

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-25148857520257486062009-10-28T15:38:00.000+05:302009-10-28T15:45:58.421+05:30SED Delimiters and usage

Delimiters in SED substitute command @ % | ; : The follwing two commands are same. sed 's@/home/@/myhome@g' saple.txt sed 's/\/home\//\/myhome\//g' saple.txt The part of an input line on which the Regular Expression matches is represented by & , and It can be used in the replacement part. sed 's/input/&output/g' output: inputoutput Grouping can be used in sed like normal

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0tag:blogger.com,1999:blog-2470916535636323458.post-36995873214560064872009-09-29T17:35:00.000+05:302009-09-29T18:25:58.803+05:30Increasing open files limit on Linux

Q) How to check open files limit on Linux ? A) ulimit -a ulimit Provides control over the resources available to the shell and to processes started by it, on systems that allow such control. -a All current limits are reported [testuser@localhost /]$ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0

rkhttp://www.blogger.com/profile/10361716792541143809noreply@blogger.com0