java programming laguage

1.Input - Output data types.
 input data:
 import java.util.Scanner;
Scanner scan = new Scanner( System.in ); 
Random random   =new Random();
double radius = scan.nextDouble();
radius =   random  .nextDouble();
output data:
System.out.print...;
2.Arrays and ArrayList

 Arrays :
declaring and creating   arrays
int[] c =new int[12 ];
String[] b = new String[100];// create array b

int[] c;// declare the array variable
c=new int[ 12];// create the array; assign to array variable
Using an Array Initializer
int[] n = {10, 20,30,40,50 };
types :
length of array : array.length()

try{

} // end try -  out of range
catch( ArrayIndexOutOfBoundsException e ){/

} // end catch

for (parameter :arrayName )
statement

ArrayList :
ArrayList< String > list;

ArrayList< String > items = new ArrayList< String >();
3 . variable :
final  int number = 10 ; // this declare  const
4 Class and objects.
 Java supports onlysingle inheritance :extends+superand a dot (.) separator+protected. +@Override
 Polymorphism
5 .Throwing exceptions
type fuction( data type .){
if(condition){
}
 else{
throw new IllegalArgumentException( "...." );
}
}


try{
   type fuction( data type .)
}
catch ( IllegalArgumentException e ){
    System.out.printf(e.getMessage() );
} // end catch
http://www.tutorialspoint.com/log4j/index.htm
checkstyle-5.1
http://www.uml-diagrams.org/use-case-diagrams.html
code refactoring
http://www.refactoring.com/catalog/index.html
Debugging & Tracing the Application
page : 350