Concepts Archives - Page 9 of 14

Processes and Threads

Apr

10

2013

Processes A processes is the “heaviest” unit of kernel scheduling. Processes own resources allocated by the operating system. Resources include a. memory b. file handler c. sockets d. device handler e. windows Processes do not share address space or file resources except through explicit methods such as inheriting file handles or shared memory segments or ...

Hardwired control and Micro-programmed control

Apr

10

2013

There are two major types of control organization – Hardwired control and micro-programmed control. S.No. Hardwired Control Micro-programmed Control 1. The control logic is implemented with gates, flip-flops, decoders. It can be optimized to produce fast mode of operation. The control information is stored in control memory. The control memory is ...

Instruction codes

Apr

10

2013

The organization of the computer is defined by its internal registers, the timing and control structure and the set of instruction that it uses.The internal organization of a digital system is defined by the sequence of microoperations it performs on data stored in its registers The user of a computer can control the process by ...

Interface and Abstract Class

Apr

8

2013

An Interface declaration introduces a new reference type whose members are classes, interfaces, constants and abstract methods. This type has no implementation, but otherwise unrelated classes can implement it by providing implementations for its abstract methods. An Abstract Class is a class which contain one or more abstract methods, which has to be implemented by sub ...

Init method and Constructor in Servlet 3

Apr

8

2013

Servlet is a Java class-a special java class and it does have a no-argument constructor. When the container loads the servlet into the memory, the no-argument constructor is called.(Till now the servlet object is not a servlet but a normal POJO – plain old java object). It becomes a servlet when it is given the ...

Immutable Objects

Apr

8

2013

Immutable means unchangeable.In Java,when you have a reference to an instance of an object, the contents of that instance cannot be altered, that is objects that you cannot change the contents after they have been set. All of the java.lang package wrapper classes are immutable: Boolean, Byte, Character, Double, Float, Integer, Long, Short, String. How ...

HTML ASCII Reference

Apr

7

2013

ASCII Printable Characters ASCII Character HTML Entity Code Description   space ! ! exclamation mark “ " quotation mark # # number sign $ $ dollar sign % % percent sign & & ampersand ‘ ' apostrophe ( ( left parenthesis ) ) right parenthesis * * asterisk + + plus sign , , ...

Hashmap and Hashtable

Apr

7

2013

The HashMap class is roughly equivalent to Hashtable, except that it is non synchronized and permits nulls. (HashMap allows null values as key and value whereas Hashtable doesn’t allow nulls). However, HashMap can be synchronized using Map m = Collections.synchronizeMap(hashMap); Hashtable and HashMap are member of the Java Collections Framework (since Java 2 platform v1.2, ...

Frameworks

Apr

7

2013

A Framework is a set of reusable classes that forms the foundation of the java application. It is a layered structure that indicates how the components of the application should be developed and how they are interrelated. Framework helps the programmers to build application quickly. Some Java frameworks 1. Hibernate 2. Spring 3. Struts 4. ...

Bizzare Eclipse Problem

Apr

6

2013

Here we explain a very bizarre yet interesting issue that occurs in Eclipse IDE. Problem Description : Sometime(s) while writing a new method, specifically, while writing its signature, Eclipse IDE keeps on selecting the method name typed so far. The situation is depicted in the following two screens : In the first screen I begin ...