Sorting with Java

SelectionSort – int Array

public class SelectionSort {

public int[] selectionSort(int[] data) {
int lenD = data.length;
int j = 0;
int tmp = 0;
for (int i = 0; i < lenD; i++) {
j = i;
for (int k = i; k data[k]) {
j = k;
}
}
tmp = data[i];
data[i] = data[j];
data[j] = tmp;
}
return data;
}

public static void main(String args[]){
SelectionSort selectionSort = new SelectionSort();
int a[] = {2,3,6,4,9,7};
int b[] = selectionSort.selectionSort(a);
for(int i = 0; i < b.length; i++){
System.out.println(b[i]);
}
}
}

Selection Sort – String array
public class selectionSort2 {
public static void selectionSort(String[] data) {
for (int numSort = 0; numSort < data.length-1; numSort++){
// find the next minimum
int minPos = numSort; // initial position of next min
for (int pos = numSort+1; pos 0)
minPos = pos; // found new min
}
// swap in min to next position in sorted list
String temp = data[minPos];
data[minPos] = data[numSort];
data[numSort] = temp;
}
}

public static void main(String args[]){
String a[] = {"kamal", "amal", "sujith", "nimal", "jagath"};
selectionSort(a);
for(int i = 0; i < a.length; i ++){
System.out.println(a[i]);
}
}
}

InsertionSort – int Array

public class InsertionSort {
public int[] insertionSort(int[] data){
int len = data.length;
int key = 0;
int i = 0;
for(int j = 1;j=0 && data[i]>key){
data[i+1] = data[i];
i = i-1;
data[i+1]=key;
}
}
return data;
}

public static void main(String args[]){
InsertionSort insertionSort = new InsertionSort();
int a[] = {2,3,6,4,9,7};
int b[] = insertionSort.insertionSort(a);
for(int i = 0; i < b.length; i++){
System.out.println(b[i]);
}
}
}


Bubble Sort – int array
public class BubbleSort {
public int[] bubbleSort(int[] data){
int lenD = data.length;
int tmp = 0;
for(int i = 0;i=(i+1);j--){
if(data[j]<data[j-1]){
tmp = data[j];
data[j]=data[j-1];
data[j-1]=tmp;
}
}
}
return data;
}

public static void main(String args[]){
BubbleSort bubbleSort = new BubbleSort();
int a[] = {2,3,6,4,9,7};
int b[] = bubbleSort.bubbleSort(a);
for(int i = 0; i < b.length; i++){
System.out.println(b[i]);
}

}
}

http://www.cs.ucf.edu/courses/cop3502/nihan/spr03/sort.pdf

Using Collections.sort and Comparable in Java

Comparable is used for sort Java object based on its property value.To sort an Object by its property, you have to make the Object implement the Comparable interface and override the compareTo() method. Lets see How Car object sort by Car Size.

package com.test;

public class Car implements Comparable{
private String carType;
private int size;
private String colour;
public String getCarType() {
return carType;
}
public void setCarType(String carType) {
this.carType = carType;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public String getColour() {
return colour;
}
public void setColour(String colour) {
this.colour = colour;
}
@Override
public int compareTo(Car otherCar) {
int carsize = otherCar.getSize();
if(this.size > carsize){
return 1;
}
else if(this.size < carsize){
return -1;
}
else{
return 0;
}
}
}


This class use Collections.sort() method to sort car Objects

package com.test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class CompareCar{
private static List carList ;
public static List getCarList(){
carList = new ArrayList();
Car car1 = new Car();
car1.setCarType("BMW");
car1.setColour("RED");
car1.setSize(350);

Car car2 = new Car();
car2.setCarType("ALLION");
car2.setColour("YELLOW");
car2.setSize(200);

Car car3 = new Car();
car3.setCarType("SUZUKI");
car3.setColour("BLACK");
car3.setSize(1000);

Car car4 = new Car();
car4.setCarType("ALTO");
car4.setColour("BULE");
car4.setSize(400);

carList.add(car1);
carList.add(car2);
carList.add(car3);
carList.add(car4);
return carList;
}

public static void printValue(List carLIST){
for (int a = 0; a" + carLIST.get(a).getCarType() + " Car Colour -> " + carLIST.get(a).getColour()
+ " Car Size-> " + carLIST.get(a).getSize());
}
}

public static void main(String args[]){
List carLis = CompareCar.getCarList();
Collections.sort(carLis);
printValue(carLis);
}
}

You can see Sorted Car list details in console

Factory Design Pattern

Factory design pattern is used to create objects or Class in Java and it provides loose coupling and high cohesion. Factory pattern encapsulate object creation logic which makes it easy to change it later when you change how object gets created or you can even introduce new object with just change in one class.The factory pattern (also known as the factory method pattern) is a creational design pattern.

Let we discuss with simple example,

1. Animal Super class

package com.test.factory;
public abstract class Animal {
public abstract String makeSound();
}


2.Dog class
Dog sub class extends Animal class and Override makeSound() method and return “Woof”

package com.test.factory;
public class Dog extends Animal{
@Override
public String makeSound() {
return "Woof";
}
}


3. Cat Class
Cat sub class extends Animal class and Override makeSound() method and return “Meow”

package com.test.factory;
public class Cat extends Animal{
@Override
public String makeSound() {
return "Meow";
}
}


4.AnimalFactory Class
AnimalFactory class create Dog and Cat Object according to input

package com.test.factory;
public class AnimalFactory {
public Animal getAnimal(String type) {
if ("canine".equals(type)) {
return new Dog();
} else {
return new Cat();
}
}
}

5. Demo class
This class show how to use factory design pattern
package com.test.factory;
public class DemoClass {
public static void main(String[] args) {
AnimalFactory animalFactory = new AnimalFactory();
/* this create Cat object */
Animal a1 = animalFactory.getAnimal("feline");
System.out.println("a1 sound: " + a1.makeSound());
/* this create Dog object */
Animal a2 = animalFactory.getAnimal("canine");
System.out.println("a2 sound: " + a2.makeSound());
}
}


Java Practical Question

1). Find given number even or odd?

2). Write a program that given year is leap year or not?

3). Get out put like given below

4). If ArrayList have duplicate values, write program to get unique values?

5). If you give Birth-date(xxxx-xx-xx format). how to calculate age?

6).Load an ArrayList with Strings from a text file of names. Show the names sorted in order of first name and then by last name.

7).To show the polymorphism concept , Write program by getting example as library?

8). Find given number Prime Number or not?

9). write a program to calculate area of circle?

10). write program to find reverse number of given number?

Find exact two numbers form given numbers and equity is same as given specific number

This c is number(200). I have to find exact matching two numbers from given numbers that equity of numbers is same as c . This following algorithm find exact two numbers(70 , 130)


package src;

import java.util.Arrays;

public class Test {

public static void main(String args[]){

int c= 200;
int[] myIntArray = {25, 130, 75,54,12,70};

Arrays.sort(myIntArray);
for(int i = 0 ; i<myIntArray.length; i++){
int remain = c - myIntArray[i];

for(int x = 0;x<myIntArray.length;x++){

if(remain == myIntArray[x]){
System.out.println(myIntArray[i] + " " + myIntArray[x]);
System.exit(0);
}
}

}
}

}


Difference between Iterator and ListIterator?

Main difference is that with iterator we can travel in only one direction but with ListIterator we can travel both directions.There are advantages of ListIterator

Iterate backwards

Obtain the index at any point.

Add a new value at any point.

Set a new value at that point.

Jax-WS hello world web service

The Java API for XML Web Services (JAX-WS) is a Java programming language API for creating web services. It is part of the Java EE platform from Sun Micro systems.JAX-WS uses annotations, introduced in Java 1.5, to simplify the development and deployment of web service clients and endpoints. It is part of the Java Web Services Development Pack. JAX-WS can be used in Java SE starting with version 1.6

Pre Requirement

Familier with eclipes(Not Mandatory)

Java 1.6 above

Service
create java project in eclipes

1.Create a Web Service Endpoint Interface

package com.test.webservice;
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.jws.soap.SOAPBinding;
import javax.jws.soap.SOAPBinding.Style;
@WebService
@SOAPBinding(style = Style.RPC)
public interface JAXWS {
@WebMethod
public String helloWorld(String name);
}


2. Create a Web Service Endpoint Implementation

package com.test.webservice;
import javax.jws.WebService;
@WebService(endpointInterface = "com.test.webservice.JAXWS")
public class JAXWSImpl implements JAXWS {
@Override
public String helloWorld(String name) {
// TODO Auto-generated method stub
return "JAXWS hello world"+ name;
}
}


3. Create a Endpoint Publisher to publish web service

package com.test.webservice.endpoint;
import javax.xml.ws.Endpoint;
import com.test.webservice.JAXWSImpl;
public class JaxWSEndpoint {
public static void main(String args[]){
Endpoint.publish("http://localhost:8080/webservice/hello", new JAXWSImpl());
}
}


Now run HelloworldPublisher as java application and test the deployed web service by accessing the generated WSDL (Web Service Definition Language) document via this URL : http://localhost:8080/webservice/hello?wsdl

Client
Create new java project

1. Type following command in command prompt as bellow

This command will generate skeleton on client end.This is project explorer

2. Create class and get service
package com.test.webservice;

public class JAXWSClient {

public static void main(String args[]){
JAXWSImplService implService = new JAXWSImplService();
JAXWS jaxws = implService.getJAXWSImplPort();
System.out.println(jaxws.helloWorld("pradeep"));
}
}


You can see out put as JAXWS hello worldpradeep