Serialization in A IS-A relationship

 

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutput;

import java.io.ObjectOutputStream;

public class SerilizableISA {

public static void main(String[] args) {

System.out.println("==========Serilization Started============");

try {

//creating object of Student class

Student1 s1 = new Student1(123, "Vijay Dehraj", "Java", 50000);

//creating stream to write data into the file

FileOutputStream fos = new FileOutputStream("inheritance.txt");

ObjectOutputStream out = new ObjectOutputStream(fos);

out.writeObject(s1);

//closing the stream

out.close();

System.out.println("The state of object is saved");

System.out.println("==========Serilization Ended==============");

} catch (Exception e) {

e.printStackTrace();

}

System.out.println("==========Deserilization Started==========");

try {

//creating input stream to read the data of serialized object

ObjectInputStream ois = new ObjectInputStream(

new FileInputStream("inheritance.txt")

);

Student1 s = (Student1) ois.readObject();

//printing data of serialized object

System.out.println(s.id + " " + s.name + " " + s.course + " " + s.fee);

System.out.println("==========Deserilization Started==========");

} catch (Exception e) {

System.out.println(e);

}

}

}

Transient

 

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

class TransientDemo {

public static void main(String[] args) {

try {

//creating object of class Girl;

Girl g1 = new Girl("Bhaviya", 2345, 29);

//creating stram to write data;

FileOutputStream fos = new FileOutputStream("girl.txt");

ObjectOutputStream out = new ObjectOutputStream(fos);

out.writeObject(g1);

out.flush();

//closing stream

out.close();

fos.close();

System.out.println("Write Operation Successful");

} catch (Exception e) {

System.out.println(e);

}

//deserializaton.................

try {

//creating stream to read data;

ObjectInputStream ois = new ObjectInputStream(

new FileInputStream("girl.txt")

);

//reading data

Girl g1 = (Girl) ois.readObject();

//g1.age =0 as age is transient;

//printing the data of serilized object

System.out.println(g1.name + " " + g1.id + " " + g1.age);

ois.close();

} catch (Exception e) {

System.out.println(e);

}

}

}

Deserialization

 

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.ObjectInputStream;

class DeserializationDemo {

public static void main(String[] args)

throws IOException, FileNotFoundException, ClassNotFoundException {

//creating stream to read the object

ObjectInputStream ois = new ObjectInputStream(

new FileInputStream("student.txt")

);

Student s = (Student) ois.readObject();

//printing the data of serialized object

System.out.println(s.id + " " + s.name);

//closing the stream

ois.close();

}

}

Serialization

 

import java.io.FileOutputStream;

import java.io.ObjectOutputStream;

class SerializationDemo {

public static void main(String[] args) {

try {

Student s1 = new Student(23, "Ramakesh");

FileOutputStream fout = new FileOutputStream("student.txt");

ObjectOutputStream out = new ObjectOutputStream(fout);

out.writeObject(s1);

out.flush();

// closing the stream

out.close();

System.out.println("State of object is successfully saved");

} catch (Exception e) {

e.printStackTrace();

}

}

}

The TreeMap and its Methods

 

import java.util.TreeMap;

public class TreeMapMethods {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(22, "this");

tm.put(14, "Invent");

tm.put(24, "blog");

tm.put(20, "on");

tm.put(18, "you");

tm.put(16, "welcomes");

tm.put(12, "Java");

System.out.println("--------------------------------------");

//will give first lowest key in the TreeMap

System.out.println("The first key in the TreeMap");

System.out.println(tm.firstKey());

System.out.println("--------------------------------------");

//will give last/largest key in the TreeMap

System.out.println("The last key in the TreeMap");

System.out.println(tm.lastKey());

System.out.println("--------------------------------------");

//will give lowest key and value associated with it

System.out.println("The First Entry");

System.out.println(tm.firstEntry());

System.out.println("--------------------------------------");

//will give largest key and value associated with it

System.out.println("The last Entry");

System.out.println(tm.lastEntry());

System.out.println("--------------------------------------");

//will give value equal or less than the provided key

System.out.println("The floor entry is");

System.out.println(tm.floorEntry(15));

System.out.println("--------------------------------------");

//will give entry equal or more than the provided key

System.out.println("The Ceiling entry is");

System.out.println(tm.ceilingEntry(15));

System.out.println("--------------------------------------");

//will give key equal or more than the provided key

System.out.println("The ceiling key is");

System.out.println(tm.ceilingKey(15));

System.out.println("--------------------------------------");

//will give key equal or less than the provided key

System.out.println("The floor key is");

System.out.println(tm.floorKey(15));

System.out.println("--------------------------------------");

System.out.println("The head map is");

System.out.println(tm.headMap(16));

System.out.println("--------------------------------------");

System.out.println("The tail map is");

System.out.println(tm.tailMap(16));

System.out.println("--------------------------------------");

System.out.println("The hashcode of Our Map");

System.out.println(tm.hashCode());

System.out.println("--------------------------------------");

System.out.println("If map is empty or not?");

System.out.println(tm.isEmpty());

System.out.println("--------------------------------------");

System.out.println("The size of our Map is");

System.out.println(tm.size());

System.out.println("--------------------------------------");

System.out.println("The sorted Decending KeySet ");

System.out.println(tm.descendingKeySet());

System.out.println("--------------------------------------");

System.out.println("The decending Map ");

System.out.println(tm.descendingMap());

System.out.println("--------------------------------------");

System.out.println("The class of Tree Map");

System.out.println(tm.getClass());

System.out.println("--------------------------------------");

System.out.println("The higher entry than the key 16 is");

System.out.println(tm.higherEntry(16));

System.out.println("--------------------------------------");

System.out.println("The lower entry than the key 16 is");

System.out.println(tm.lowerEntry(16));

System.out.println("--------------------------------------");

System.out.println("The first entry of given map");

System.out.println(tm.pollFirstEntry());

System.out.println("--------------------------------------");

System.out.println("The last entry of given map");

System.out.println(tm.pollLastEntry());

System.out.println("--------------------------------------");

System.out.println("The submap of given TreeMap from key 14 to key 20");

System.out.println(tm.subMap(14, 20));

System.out.println("--------------------------------------");

System.out.println(tm.subMap(14, false, 22, false));

System.out.println(tm.subMap(14, true, 22, true));

System.out.println(tm.subMap(14, true, 22, false));

System.out.println(tm.subMap(14, false, 22, true));

System.out.println("--------------------------------------");

System.out.println("The Key Set of our Mapping is");

System.out.println(tm.navigableKeySet());

System.out.println("--------------------------------------");

}

}

Printing the mappings of a TreeMap using entrySet()

 

import java.util.TreeMap;

public class TreeMapEntrySet {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(17, "this");

tm.put(13, "Invent");

tm.put(18, "blog");

tm.put(16, "on");

tm.put(15, "you");

tm.put(14, "welcomes");

tm.put(12, "Java");

System.out.println("Mappings of TreeMap are");

System.out.println(tm.entrySet());

}

}

Searching a Key and finding value associated with it in a TreeMap

 

import java.util.Scanner;

import java.util.TreeMap;

public class MapTreeContainKey {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(17, "this");

tm.put(13, "Invent");

tm.put(18, "blog");

tm.put(16, "on");

tm.put(15, "you");

tm.put(14, "welcomes");

tm.put(12, "Java");

Scanner sc = new Scanner(System.in);

System.out.println("Enter the key you want to search");

Integer key = sc.nextInt();

if (tm.containsKey(key)) {

System.out.println("Key is present and value associated with it is : ");

System.out.println(tm.get(key));

} else {

System.out.println("key not found");

}

}

}

Cloning a TreeMap

 

import java.util.TreeMap;

public class TreeMapClone {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(17, "this");

tm.put(13, "Invent");

tm.put(18, "blog");

tm.put(16, "on");

tm.put(15, "you");

tm.put(14, "welcomes");

tm.put(12, "Java");

System.out.println("The clone of TreeMap is");

System.out.println(tm.clone());

}

}

Removing element from a TreeMap

import java.util.TreeMap;

public class TreeMapRemove {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(17, "this");

tm.put(13, "Invent");

tm.put(18, "blog");

tm.put(16, "on");

tm.put(15, "you");

tm.put(14, "welcomes");

tm.put(12, "Java");

//deleting element from TreeMap

System.out.println("Before invoking remove opeation the mapping is");

System.out.println(tm);

tm.remove(12);

System.out.println("After invoking remove opeation the mapping is");

System.out.println(tm);

tm.remove(14, "welcomes");

System.out.println("After invoking remove opeation the mapping is");

System.out.println(tm);

tm.clear();

System.out.println("After invoking remove opeation the mapping is");

System.out.println(tm);

}

}

 

Adding element to a TreeMap and iterating using iterator and printing its key-value set

 

import java.util.Iterator;

import java.util.TreeMap;

public class TreeMapPut {

public static void main(String[] args) {

//creating our tree map

TreeMap<Integer, String> tm = new TreeMap<>();

//Inserting element in our TreeMap

tm.put(17, "this");

tm.put(13, "Invent");

tm.put(18, "blog");

tm.put(16, "on");

tm.put(15, "you");

tm.put(14, "welcomes");

tm.put(12, "Java");

Iterator itr = tm.keySet().iterator();

while (itr.hasNext()) {

Integer key = (Integer) itr.next();

String value = tm.get(key);

System.out.println(key + "---->" + value);

}

}

}

Getting a value associated with a key using key in a LinkedHashMap

 

import java.util.LinkedHashMap;

import java.util.Scanner;

public class HashMapGet {

public static void main(String[] args) {

LinkedHashMap<Integer, String> lhm = new LinkedHashMap<>();

//adding element to our LinkedHashMap

lhm.put(21, "Amit");

lhm.put(5, "Rahul");

lhm.put(13, "Veeru");

lhm.put(34, "Subhash");

lhm.put(19, "Saahil");

System.out.println("Initial mapping is :");

System.out.println(lhm);

Scanner sc = new Scanner(System.in);

System.out.println("Enter the Key to find associated value with it");

int n = sc.nextInt();

System.out.println("The value associated with the entered key is :");

System.out.println(lhm.get(n));

}

}

Deleting element from a LinkedHashMap

 

import java.util.LinkedHashMap;

public class MapRemove {

public static void main(String[] args) {

//creating LinkedHashMap

LinkedHashMap<Integer, String> lhm = new LinkedHashMap<>();

//adding element to our LinkedHashMap

lhm.put(21, "Amit");

lhm.put(5, "Rahul");

lhm.put(13, "Veeru");

lhm.put(34, "Subhash");

lhm.put(19, "Saahil");

//removing one element from out map

System.out.println("Before invoking remove() method,the mapping :");

System.out.println(lhm);

lhm.remove(21);

System.out.println();

System.out.println("After invoking remove() method,the mapping :");

System.out.println(lhm);

System.out.println();

lhm.remove(34, "Subhash");

System.out.println("After invoking remove() method again,the mapping :");

System.out.println(lhm);

System.out.println();

lhm.clear();

System.out.println("After invoking clear() method,the mapping :");

System.out.println(lhm);

}

}

Printing Keys, value, and Key-value Pair of a LinkedHashMap.

import java.util.LinkedHashMap;

public class LinkedHashMapPrint {

public static void main(String[] args) {

//creating LinkedHashMap

LinkedHashMap<Integer, String> lhm = new LinkedHashMap<>();

//adding element to our LinkedHashMap

lhm.put(21, "Amit");

lhm.put(5, "Rahul");

lhm.put(13, "Veeru");

lhm.put(34, "Subhash");

lhm.put(19, "Saahil");

System.out.println("Keys = " + lhm.keySet());

System.out.println("Values = " + lhm.values());

System.out.println("Key-value Pair Set = " + lhm.entrySet());

}

}

Creating a LinkedHashMap and adding elements to it and printing the elements

 

import java.util.LinkedHashMap;

import java.util.Map;

public class AddDemo {

public static void main(String[] args) {

//creating LinkedHashMap

LinkedHashMap<Integer, String> lhm = new LinkedHashMap<>();

//adding element to our LinkedHashMap

lhm.put(21, "Amit");

lhm.put(5, "Rahul");

lhm.put(13, "Veeru");

lhm.put(34, "Subhash");

lhm.put(19, "Saahil");

//printing values using for each loop

//insertion order is maintained in LinkedHashMap

for (Map.Entry m : lhm.entrySet()) {

System.out.println(

"key = " + m.getKey() + "," + "Value = " + m.getValue()

);

}

}

}

Getting Keys stored Hashtable using Enumeration

 

import java.util.Enumeration;

import java.util.Hashtable;

public class HashtableKeys {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Reena");

ht.put(51, "Anmol");

ht.put(16, "Veer");

ht.put(27, "Rekha");

Enumeration enu = ht.keys();

while (enu.hasMoreElements()) {

System.out.println(enu.nextElement());

}

}

}

Searching value in a Hashtable using containsValue() method

 

import java.util.Hashtable;

public class HashMapContainsValue {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

//Adding element to our Table ht

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Tina");

ht.put(51, "Anmol");

ht.put(16, "Veer");

ht.put(27, "Tina");

System.out.println("Is 'Tina' is present in the table ?");

System.out.println(ht.containsValue("Tina"));

}

}

Searching a value in Hashtable using contains() method

 

import java.util.Hashtable;

public class HashtableContains {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

//Adding element to our Table ht

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Gravit");

ht.put(51, "Anmol");

ht.put(16, "Veer");

System.out.println("Is 'Tina' is present in the table ?");

System.out.println(ht.contains("Tina"));

System.out.println("Is 'Veera' is present in the table ?");

System.out.println(ht.contains("Veera"));

}

}

Cloning a Hashtable Using in-built method Clone()

 

import java.util.Hashtable;

public class HashTableClone {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

//adding element to our Table

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Gravit");

ht.put(51, "Anmol");

ht.put(16, "Veer");

Hashtable<Integer, String> ht_clone = (Hashtable) ht.clone();

System.out.println("Original Table is :" + ht);

System.out.println("cloned Table is : " + ht_clone);

}

}

Removing or Deleting an element or removing all elements from a HashTable

 

import java.util.Hashtable;

public class HashTableRemove {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Gravit");

ht.put(51, "Anmol");

ht.put(16, "Veer");

//null value can not be added in HashTable

// ht.put(null, null);

//printing out Table

System.out.println("Original Our Table is : ");

System.out.println(ht);

//remvoing element from out Table

ht.remove(31);

System.out.println("Mapping of ht after first removal" + ht);

ht.remove(51, "Anmol");

System.out.println("Mapping of ht after Second removal" + ht);

    //removing all element from the table

ht.clear();

System.out.println("Mapping of ht after first removal" + ht);

}

}

Replacing element in a HashTable

 

import java.util.Hashtable;

public class HashTableReplaceElement {

public static void main(String[] args) {

Hashtable<Integer, String> ht = new Hashtable<>();

ht.put(31, "Vidya");

ht.put(12, "Sambhavna");

ht.put(33, "Tina");

ht.put(45, "Gravit");

ht.put(51, "Anmol");

ht.put(16, "Veer");

//replacing element

ht.put(51, "Shakira");

System.out.println("Mapping of ht is : ");

System.out.println(ht);

}

}