TIBCO RV FIX PROTOCOL JAVA TUTORIAL

How to set JAVA_HOME environment in Linux, Unix and Windows

2012-02-21T21:34:00.000-08:00

JAVA_HOME is a system environment variable which represent JDK installation directory. When you install JDK in your machine (windows, Linux or unix) it creates a home directory and puts all its binary (bin), library(lib) and other

tools. In order to compile java program "javac" tool should be in your PATH and in order to get that in PATH

we use JAVA_HOME environment variable. Many tools like ANT and web servers like tomcat use JAVA_HOME to find java binaries. In this article we will see how to set JAVA_HOME environment variable in different operating system including Windows (windows 7, vista, xp) and Linux (Unix).

What is Race Condition in multithreading – 2 Examples in Java

2012-02-21T21:08:00.000-08:00

Race condition in Java is a type of concurrency bug or issue which is introduced in your program because parallel execution of your program by multiple threads at same time, Since Java is a multi-threaded programming language hence risk of Race condition is higher in Java which demands clear understanding of what causes a race condition and how to avoid that. Anyway Race conditions are just one of hazards or risk presented by use of multi-threading in Java just like deadlock in Java. Race conditions occurs when two thread operate on same object without proper synchronization and there operation interleaves on each other. Classical example of Race condition is incrementing a counter since increment is not an atomic operation and can be further divided into three steps like read, update and write. if two threads tries to increment count at same time and if they read same value because of interleaving of read operation of one thread to update operation of another thread, one count will be lost when one thread overwrite increment done by other thread. atomic operations are not subject to race conditions because those operation cannot be interleaved. This is also a popular multi-threading interview questions during core java interviews. In this article we will see how to find race condition in Java and two sample code patterns which often causes race conditions in Java.

JSTL set tag or examples in JSP – Java J2EE Tutorial

2012-02-21T17:30:00.001-08:00

JSTL set tag or <c:set> also called as JSTL Core tag library is a good replacement of <jsp:setProperty> jsp action which lacks lot of functionality and only allow you to set bean property. you can not set Map's key value or create a scoped variable by using <jsp:setProperty>. jstl <set> tag allows you to do all the stuff related to setting or creating variables or attributes. by using JSTL <c:set> tag you can :

Difference between throw and throws in Exception handling - Java Example

2012-02-21T06:08:00.000-08:00

Difference between throw and throws keyword on Exception handling in Java is a popular core java interview question. Exception handling being an important part of Java programming language, complete knowledge of all keywords related to exception handling e.g. try, catch, finally, throw and throws is important. Main difference between throw and throws is in there usage and functionality. where throws is used in method signature to declare Exception possibly thrown by any method, throw is actually used to throw Exception in Java code, here is an example of both throw and throws keyword which makes it easy to understand difference between them.

Difference between LinkedList vs ArrayList in Java

2012-02-18T18:44:00.000-08:00

LinkedList and ArrayList both implement List Interface but how they work internally is where the differences lies. Main difference between ArrayList and LinkedList is that ArrayList is implemented using re sizable array while LinkedList is implemented using doubly LinkedList. ArrayList is more popular among Java programmer than LinkedList as there are few scenarios on which LinkedList is a suitable collection than ArrayList. In this article we will see some differences between LinkedList and ArrayList and try to find out when and where to use LinkedList over ArrayList.

How to encode decode String in Java base64 Encoding

2012-02-17T06:38:00.000-08:00

Encoding and Decoding of String in Java using base64 is extremely easy if you are using apache commons code open

source library. it provides convenient static utility method Base64.encodeBase64(byte[]) and Base64.decodeBase64(byte []) for converting binary data into base64 encoded binary Stream and than decoding back from encoded data in base64 encoding mechanism. Many times we need to encode sensitive data be it binary String format transferring over socket or transferring or storing data in xml files. Though there are other open source library available which provides support to encode any String into base64 e.g. MimeUtil from javax.mail package but Apache commons codec package is really handy and doesn't add lot of extra stuff. its API is also very neat and clean. In this article we will see how to encode and decode String into base64 encoding.

Producer Consumer Design Pattern with Blocking Queue Example in Java

2012-02-16T05:44:00.000-08:00

Producer Consumer Design pattern is a classic concurrency or threading pattern which reduces coupling between

Producer and Consumer by separating Identification of work with Execution of Work. In producer consumer design pattern a shared queue is used to control the flow and this separation allows you to code producer and consumer separately. It also addresses the issue of different timing require to produce item or consuming item. by using producer consumer pattern both Producer and Consumer Thread can work with different speed. In this article we will see What is producer consumer problem which is very popular multi-threading interview question, How to solve producer consumer problem using Blocking Queue and Benefits of using Producer Consumer design pattern.

Why non-static variable cannot be referenced from a static context?

2012-02-15T04:56:00.000-08:00

"non-static variable cannot be referenced from a static context" is biggest nemesis of some one who has just

started programming and that too in Java. Since main method in java is most popular method among all beginners and

they try to put program code there they face "non-static variable cannot be referenced from a static context" compiler error when they try to access a non static member variable inside main in Java which is static. if you want to know

why main is declared static in Java see the link.

fail-safe vs fail-fast Iterator in Java

2012-02-10T23:01:00.000-08:00

Difference between fail-safe and fail-fast Iterator is becoming favorite core java interview questions day by day, reason

it touches concurrency a bit and interviewee can go deep on it to ask how fail-safe or fail-fast behavior is implemented.

In this article article we will see what is fail-safe and fail fast iterators in java and differences between fail-fast and fail-safe iterators . Concept of fail-safe iterator are relatively new in Java and first introduced with Concurrent Collections in Java 5 like ConcurrentHashMap and CopyOnWriteArrayList.

How to fix java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory

2012-02-08T06:39:00.000-08:00

java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory or "Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory" exception comes when you don't apache commons-logging-1.1.1.jar in your Classpath. I have faced this exception many times while using open source framework like Struts, Spring and Displaytag which uses commons-logging framework for logging. commons-logging is not an actual java logging framework but provides a wrapper so that you can use log4j, java logging or any other Java logging framework. commons-logging is also smart enough to detect which logging framework are you using e.g if you are using log4j it can detect it by looing log4j.jar in your classpath. but if you don't have commons-logging.jar in your classpath you may get java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory at runtime even if your application gets deployed successfully.

What is blocking methods in Java and how do deal with it?

2012-02-06T06:20:00.000-08:00

Blocking methods in Java are those method which block the executing thread until there operation finished. Famous

example of blocking method is InputStream read() method which blocks until all data from InputStream has been read

completely. Correct understanding of blocking methods are required if you are serious towards Java programming specially

in early days because if not used carefully blocking method can freeze GUIs, hung your program and become non responsive for longer duration of time. In this post we will see What is Blocking methods in Java, Examples of Blocking methods and Some best practices around blocking methods and how to use blocking methods in Java.