java applet

java applet :

Java Applets in HTML

Important Note:

There is now very limited applet support in most modern browsers, as they no longer support the NPAPI plugin required for showing Java applets. This page exists as a reference only. Please see Java Chrome FAQ or JDK9 Plugin FAQ on the Java website.

An applet is a Java program that can be included a web page by using HTML tags. The applet tag is the simpler but older method, and has been superseded by the object tag.

Applet - <applet> </applet>

Add a Java applet by specifying the attributes of the applet tag.

archive="url" - Address or filename of the Java archive file (.jar) containing the class files.

code="?" - Java class to run, eg. MyApplet.class

width="?" - The width of the applet, in pixels.

height="?" - The height of the applet, in pixels.

Object - <object> </object>

Use these attributes of the object tag to include an applet in html:

archive="url" - Address or filename of the Java archive file (.jar) containing the class files.

classid="?" - Java class to run, eg. java:MyApplet.class

codetype="application/java" - The type of object, use application/java.

width="?" - The width of the object, in pixels.

height="?" - The height of the object, in pixels.

Example:

Using both applet and object to show an applet

<html><body>
 <p>
  <applet code="Logo.class" archive="Logo.jar"
   width="740" height="400"></applet>
 </p>
 <p>
  <object codetype="application/java" classid="java:Logo.class"
   archive="Logo.jar" width="740" height="400"></object>
 </p>
</body></html>

java

java basics syntax

When we consider a Java program, it can be defined as a collection of objects that communicate via invoking each other's methods. Let us now briefly look into what do class, object, methods, and instance variables mean.

Object − Objects have states and behaviors. Example: A dog has states - color, name, breed as well as behavior such as wagging their tail, barking, eating. An object is an instance of a class.
Class − A class can be defined as a template/blueprint that describes the behavior/state that the object of its type supports.
Methods − A method is basically a behavior. A class can contain many methods. It is in methods where the logics are written, data is manipulated and all the actions are executed.
Instance Variables − Each object has its unique set of instance variables. An object's state is created by the values assigned to these instance variables.

First Java Program

Let us look at a simple code that will print the words Hello World.

Example

public class MyFirstJavaProgram {

   /* This is my first java program.
    * This will print 'Hello World' as the output
    */

   public static void main(String []args) {
      System.out.println("Hello World"); // prints Hello World
   }
}

Let's look at how to save the file, compile, and run the program. Please follow the subsequent steps −

Open notepad and add the code as above.
Save the file as: MyFirstJavaProgram.java.
Open a command prompt window and go to the directory where you saved the class. Assume it's C:\.
Type 'javac MyFirstJavaProgram.java' and press enter to compile your code. If there are no errors in your code, the command prompt will take you to the next line (Assumption : The path variable is set).
Now, type ' java MyFirstJavaProgram ' to run your program.
You will be able to see ' Hello World ' printed on the window.

Output

C:\> javac MyFirstJavaProgram.java
C:\> java MyFirstJavaProgram 
Hello World

Basic Syntax

About Java programs, it is very important to keep in mind the following points.

Case Sensitivity − Java is case sensitive, which means identifier Hello and hello would have different meaning in Java.
Class Names − For all class names the first letter should be in Upper Case. If several words are used to form a name of the class, each inner word's first letter should be in Upper Case.

Example: class MyFirstJavaClass
Method Names − All method names should start with a Lower Case letter. If several words are used to form the name of the method, then each inner word's first letter should be in Upper Case.

Example: public void myMethodName()
Program File Name − Name of the program file should exactly match the class name.

When saving the file, you should save it using the class name (Remember Java is case sensitive) and append '.java' to the end of the name (if the file name and the class name do not match, your program will not compile).

Example: Assume 'MyFirstJavaProgram' is the class name. Then the file should be saved as 'MyFirstJavaProgram.java'
public static void main(String args[]) − Java program processing starts from the main() method which is a mandatory part of every Java program.

Install apps or tar gz files in linux are unix operating systems

linux and unix system install commands

LINUX and UNIX

NAME

ginstall - copy files and set attributes

SYNOPSIS

install [OPTION]... SOURCE DEST (1st format)
install [OPTION]... SOURCE... DIRECTORY (2nd format)
install -d [OPTION]... DIRECTORY... (3rd format)

DESCRIPTION

In the first two formats, copy SOURCE to DEST or multiple SOURCE(s) to the existing DIRECTORY, while setting permission modes and owner/group. In the third format, create all components of the given DIRECTORY(ies).

Mandatory arguments to long options are mandatory for short options too.

--backup[=CONTROL] make a backup of each existing destination file

-b

like --backup but does not accept an argument

-c

(ignored)

-C

Install file, unless target already exists and is the same as the new file, in which case the modification time won't be changed.

-d, --directory

treat all arguments as directory names; create all components of the specified directories

-D

create all leading components of DEST except the last, then copy SOURCE to DEST; useful in the 1st format

-g, --group=GROUP

set group ownership, instead of process' current group

-m, --mode=MODE

set permission mode (as in chmod), instead of rwxr-xr-x

-o, --owner=OWNER

set ownership (super-user only)

-p, --preserve-timestamps

apply access/modification times of SOURCE files to corresponding destination files

-s, --strip

strip symbol tables, only for 1st and 2nd formats

-S, --suffix=SUFFIX override the usual backup suffix

-v, --verbose

print the name of each directory as it is created

--help

display this help and exit

--version

output version information and exit

The backup suffix is `~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX. The version control method may be selected via the --backup option or through the VERSION_CONTROL environment variable.

Here are the values:

none, off

never make backups (even if --backup is given)

numbered, t

make numbered backups

existing, nil

numbered if numbered backups exist, simple otherwise

simple, never

always make simple backups

Example:Say u need to install all .py files in a destination directory. So the following process can be followed :

$ install -d /dest/path

This creates the directory hierarchy prior to installing. AND THEN

$ install -D /source/path/*.py /dest/path

This installs all the files in the corresponding directories created.

dhivagar tech