Hiberna

Introductio with Collection Framework

Introductio with Collection Framework:

Collection is an Interface ... which provide us a well defined set of interfaces and classes to handle  and manipulate a group or collection of objects.

List and Set  are Interfaces and  both of them extends the Collection Interface.

List : --List is an ordered collection of objects which has the indexing property  and allows  duplicates...
The methods includedin it are given in the table bellow....
        

void	add(int index, Object element) Inserts the specified element at the specified position in this list (optional operation).
boolean	add(Object o) Appends the specified element to the end of this list (optional operation).
boolean	addAll(Collection c) Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator (optional operation).
boolean	addAll(int index, Collection c) Inserts all of the elements in the specified collection into this list at the specified position (optional operation).
void	clear() Removes all of the elements from this list (optional operation).
boolean	contains(Object o)           Returns true if this list contains the specified element.
boolean	containsAll(Collection c) Returns true if this list contains all of the elements of the specified collection.
boolean	equals(Object o) Compares the specified object with this list for equality.
Object	get(int index) Returns the element at the specified position in this list.
int	hashCode() Returns the hash code value for this list.
int	indexOf(Object o) Returns the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element.
boolean	isEmpty() Returns true if this list contains no elements.
Iterator	iterator() Returns an iterator over the elements in this list in proper sequence.
int	lastIndexOf(Object o) Returns the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element.
ListIterator	listIterator() Returns a list iterator of the elements in this list (in proper sequence).
ListIterator	listIterator(int index) Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.
Object	remove(int index) Removes the element at the specified position in this list (optional operation).
boolean	remove(Object o) Removes the first occurrence in this list of the specified element (optional operation).
boolean	removeAll(Collection c) Removes from this list all the elements that are contained in the specified collection (optional operation).
boolean	retainAll(Collection c) Retains only the elements in this list that are contained in the specified collection (optional operation).
Object	set(int index, Object element) Replaces the element at the specified position in this list with the specified element (optional operation).
int	size() Returns the number of elements in this list.
List	subList(int fromIndex, int toIndex) Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
Object[]	toArray() Returns an array containing all of the elements in this list in proper sequence.
Object[]	toArray(Object[] a) Returns an array containing all of the elements in this list in proper sequence; the runtime type of the returned array is that of the specified array.

Class which impelements List...are ArrayList and LinkedList

Set :-- Set is  a collection of unique objects which forbids  duplicate objects..

the methods included in Set are given in the table below...

boolean	add (Object o) Ensures that this collection contains the specified element (optional operation).
boolean	addAll(Collection c) Adds all of the elements in the specified collection to this collection (optional operation).
void	clear() Removes all of the elements from this collection (optional operation).
boolean	contains(Object o) Returns true if this collection contains the specified element.
boolean	containsAll(Collection c) Returns true if this collection contains all of the elements in the specified collection.
boolean	equals(Object o) Compares the specified object with this collection for equality.
int	hashCode() Returns the hash code value for this collection.
boolean	isEmpty() Returns true if this collection contains no elements.
Iterator	iterator() Returns an iterator over the elements in this collection.
boolean	remove(Object o) Removes a single instance of the specified element from this collection, if it is present (optional operation).
boolean	removeAll(Collection c) Removes all this collection's elements that are also contained in the specified collection (optional operation).
boolean	retainAll(Collection c) Retains only the elements in this collection that are contained in the specified collection (optional operation).
int	size() Returns the number of elements in this collection.
Object[]	toArray() Returns an array containing all of the elements in this collection.
Object[]	toArray(Object[] a) Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.

Class which impelements set...Hashset and TreeSet.
Vector :--  A Vector is an historical collection class that acts like a growable array, but can store heterogeneous data elements.It is synchronized and thread safe.

Map :--  Map is  also an interface but not extends the Collection Interface.It is a key-value association of objects with unique key .

Class Which Implements Map ... Hashmap and TreeMap.... 

Introduction with comperator and comperable

Introduction with comperator and comperable:

Comperator and comperable are interfaces used for compairing objects .

Implementation of Comparator and Comperable Interfaces

class Student implements Comparator<Student>{
   private String name;
   private int age;
   Student(){   }

   Student(String stdName, int stdAge){
      name = stdName;
      age = stdAge;
   }

   public String getName(){
      return name;
   }

   public int getAge(){
      return age;
   }

   
   // Overriding the compare method to sort the age 
   public int compare(Student s1, Student s2){
      return s1.age - s2.age;
   }
}

public class Member implements comperable<Member>{

   private String name;
   private int age;
    Member(){
   }

   Student(String memName, int mebAge){
      name = mebName;
      age = mebAge;
   } 

 // Overriding the compareTo method
   public int compareTo(Member mem){
      return (this.name).compareTo(mem.name);
   }

}

 public class MainClass{
   public static void main(String args[]){
     
      List<Student> list = new ArrayList<Student>();

      list.add(new Student("Roma",20));
      list.add(new Student("Rama",12));
      list.add(new Student("Froger",10));
      list.add(new Student("Raghav",14));
      list.add(new Student("Nammy",11));
      Collections.sort(list);// Sorts the array list

      for(Student a: list)//printing the sorted list of names
         System.out.print(a.getName() + ", ");

      // Sorts the array list using comparator
      Collections.sort(list, new Student());
      System.out.println(" ");
      for(Student a: list)//printing the sorted list of ages
         System.out.print(a.getName() +"  : "+
   a.getAge() + ", ");
   }
}

Vector Vs ArrayList which is preferable

Vector Vs ArrayList

We can compare this two based on some parameters....like Synchronization, DataSize

1)Vector is synchronized while Arraylist is not synchronized.Synchronization always pay for efficiency,so it is better to use ArrayList if we don't need thread safe data acces,Other wise go for Vector.

2)The size always matters,--Both vector and ArrayList are resizable(dynamic for their size),
but when size increase..Vector increase it's size by double and on the other hand ArrayList increases it's size by half of  its previous size.So it is better to use ArrayList wrt size.

3)Arraylist are faster and speedup the execution while vector are less efficient than ArrayList.

4)Vector is threadsafe while ArrayList is not threadsafe.

JSF Core Tags

Tag	Description
view	Creates the top-level view
subview	Creates a subview of a view
facet	Adds a facet to a component
attribute	Adds an attribute (key/value) to a component
param	Adds a parameter to a component
actionListener	Adds an action listener to a component
valueChangeListener	Adds a valuechange listener to a component/>
convertDateTime	Adds a datetime converter to a component

convertNumber
Adds a number converter to a component
validator
Adds a validator to a component
validateDoubleRange
Validates a double range for a component’s value
validateLength
Validates the length of a component’s value
validateLongRange
Validates a long range for a component’s value
loadBundle
Loads a resource bundle, stores properties as a Map
selectitems
Specifies items for a select one or select many
selectitem
Specifies an item for a select one or select many component
verbatim
Adds markup to a JSF page