reverse a number

 public int reverseNumber(int number){
       
        int reverse = 0;
        while(number != 0){
            reverse = (reverse*10)+(number%10);
            number = number/10;
        }
        return reverse;
    }

Maximum repeated words from file

mport java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Map.Entry;

public class MaxDuplicateWordCount {
   
    public Map getWordCount(String fileName){

        FileInputStream fis = null;
        DataInputStream dis = null;
        BufferedReader br = null;
        Map wordMap = new HashMap();
        try {
            fis = new FileInputStream(fileName);
            dis = new DataInputStream(fis);
            br = new BufferedReader(new InputStreamReader(dis));
            String line = null;
            while((line = br.readLine()) != null){
                StringTokenizer st = new StringTokenizer(line, " ");
                while(st.hasMoreTokens()){
                    String tmp = st.nextToken().toLowerCase();
                    if(wordMap.containsKey(tmp)){
                        wordMap.put(tmp, wordMap.get(tmp)+1);
                    } else {
                        wordMap.put(tmp, 1);
                    }
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try{if(br != null) br.close();}catch(Exception ex){}
        }
        return wordMap;
    }
   
    public List> sortByValue(Map wordMap){
       
        Set> set = wordMap.entrySet();
        List> list = new ArrayList>(set);
        Collections.sort( list, new Comparator
        {
            public int compare( Map.Entry o1, Map.Entry o2 )
            {
                return (o2.getValue()).compareTo( o1.getValue() );
            }
        } );
        return list;
    }
   
    public static void main(String a[]){
        MaxDuplicateWordCount mdc = new MaxDuplicateWordCount();
        Map wordMap = mdc.getWordCount("C:/MyTestFile.txt");
        List> list = mdc.sortByValue(wordMap);
        for(Map.Entry entry:list){
            System.out.println(entry.getKey()+" ==== "+entry.getValue());
        }
    }
}

Duplicate characters in a String

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class DuplicateCharsInString {

    public void findDuplicateChars(String str){
       
        Map dupMap = new HashMap(); 
        char[] chrs = str.toCharArray();
        for(Character ch:chrs){
            if(dupMap.containsKey(ch)){
                dupMap.put(ch, dupMap.get(ch)+1);
            } else {
                dupMap.put(ch, 1);
            }
        }
        Set keys = dupMap.keySet();
        for(Character ch:keys){
            if(dupMap.get(ch) > 1){
                System.out.println(ch+"--->"+dupMap.get(ch));
            }
        }
    }
   
    public static void main(String a[]){
        DuplicateCharsInString dcs = new DuplicateCharsInString();
        dcs.findDuplicateChars("Java2Novice");
    }
}

Swapping two numbers

 public static void main(String a[]){
        int x = 10;
        int y = 20;
        System.out.println("Before swap:");
        System.out.println("x value: "+x);
        System.out.println("y value: "+y);
        x = x+y;
        y=x-y;
        x=x-y;
        System.out.println("After swap:");
        System.out.println("x value: "+x);
        System.out.println("y value: "+y);
    }

Get Distinct word

public List getDistinctWordList(String fileName){

        FileInputStream fis = null;
        DataInputStream dis = null;
        BufferedReader br = null;
        List wordList = new ArrayList();
        try {
            fis = new FileInputStream(fileName);
            dis = new DataInputStream(fis);
            br = new BufferedReader(new InputStreamReader(dis));
            String line = null;
            while((line = br.readLine()) != null){
                StringTokenizer st = new StringTokenizer(line, " ,.;:\"");
                while(st.hasMoreTokens()){
                    String tmp = st.nextToken().toLowerCase();
                    if(!wordList.contains(tmp)){
                        wordList.add(tmp);
                    }
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
            try{if(br != null) br.close();}catch(Exception ex){}
        }
        return wordList;
    }

Delete Particular Element of Array

  String[] str_array = {"item1","item2","item3"};
List list = new ArrayList(Arrays.asList(str_array));
list.remove("item2");
str_array = list.toArray(new String[0]);
System.out.println(Arrays.toString(str_array));

public static String[] removeItemFromArray(String[] input, String item) {
    if (input == null) {
        return null;
    } else if (input.length <= 0) {
        return input;
    } else {
        String[] output = new String[input.length - 1];
        int count = 0;
        for (String i : input) {
            if (!i.equals(item)) {
                output[count++] = i;
            }
        }
        return output;
    }
}

    String[] strArr = new String[]{"google","microsoft","apple"};

      final List list =  new ArrayList();

      Collections.addAll(list, strArr); 

      list.remove("apple");

      strArr = list.toArray(new String[list.size()]);

    System.out.println(Arrays.toString(strArr));

    

Remove duplicates sorted array

int all[]=new int[]{1,2,1,2,1,3,4,5,2,7};
Arrays.sort(all);
System.out.println(Arrays.toString(all));
HashSetset=new HashSet();
for(Integer a:all)
{
set.add(a);
}
System.out.println(set);

   
int[] input = {2,3,6,6,8,9,10,10,10,12,12};
ArrayList list = new ArrayList();
for(int i = 0 ; i < input.length; i++)
{
if(!list.contains(input[i]))
{
System.out.println(input[i]);
list.add(input[i]);
}
}
System.out.println(list);

private void removeTheDuplicates(ListmyList) {
    for(ListIteratoriterator = myList.listIterator(); iterator.hasNext();) {
        Customer customer = iterator.next();
        if(Collections.frequency(myList, customer) > 1) {
            iterator.remove();
        }
    }
    System.out.println(myList.toString());

}


Set s = new HashSet(listCustomer);



If you need to preserve elements order then use LinkedHashSet instead of HashSet

Set mySet = new LinkedHashSet(list);

list = new ArrayList(set);

import java.util.ArrayList;
public class Arrays extends ArrayList{

@Override
public boolean add(Object e) {
    if(!contains(e)){
        return super.add(e);
    }else{
        return false;
    }
}

public static void main(String[] args) {
    Arrays element=new Arrays();
    element.add(1);
    element.add(2);
    element.add(2);
    element.add(3);

    System.out.println(element);
}
}

Fibonacci Series

class FibonacciExample1{
public static void main(String args[])
{  
 int n1=0,n2=1,n3,i,count=10;  
 System.out.print(n1+" "+n2);//printing 0 and 1  
   
 for(i=2;i {  
  n3=n1+n2;  
  System.out.print(" "+n3);  
  n1=n2;  
  n2=n3;  
 }  
 
}} 

File Read

try (BufferedReader br = new BufferedReader(new FileReader(file))) {
    String line;
    while ((line = br.readLine()) != null) {
       // process the line.
    }
}

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public static void readText throws FileNotFoundException {
    Scanner scan = new Scanner(new File("samplefilename.txt"));
    while(scan.hasNextLine()){
        String line = scan.nextLine();
        //Here you can manipulate the string the way you want
    }
}

try( BufferedReader reader = new BufferedReader( ... ) ) {
  reader.lines().foreach( line -> processLine( line ) );
}

   String pathFile="/path/to/file.txt";
   String cmd="type";
   if(System.getProperty("os.name")=="Linux"){
       cmd="cat";
   }
   Process p= Runtime.getRuntime().exec(cmd+" "+pathFile);
    BufferedReader stdInput = new BufferedReader(new
         InputStreamReader(p.getInputStream()));
   System.out.println(p.getOutputStream().toString());
   String s = null;
    while ((s = stdInput.readLine()) != null) {
        System.out.println(s);
    }

Java Learning

http://www.java2novice.com/

Treeset Sorting

mport java.util.Comparator;
import java.util.TreeSet;

public class MyCompUserDefine {

    public static void main(String a[]){
        //By using name comparator (String comparison)
        TreeSet nameComp = new TreeSet(new MyNameComp());
        nameComp.add(new Empl("Ram",3000));
        nameComp.add(new Empl("John",6000));
        nameComp.add(new Empl("Crish",2000));
        nameComp.add(new Empl("Tom",2400));
        for(Empl e:nameComp){
            System.out.println(e);
        }
        System.out.println("===========================");
        //By using salary comparator (int comparison)
        TreeSet salComp = new TreeSet(new MySalaryComp());
        salComp.add(new Empl("Ram",3000));
        salComp.add(new Empl("John",6000));
        salComp.add(new Empl("Crish",2000));
        salComp.add(new Empl("Tom",2400));
        for(Empl e:salComp){
            System.out.println(e);
        }
    }
}

class MyNameComp implements Comparator{

    @Override
    public int compare(Empl e1, Empl e2) {
        return e1.getName().compareTo(e2.getName());
    }
}

class MySalaryComp implements Comparator{

    @Override
    public int compare(Empl e1, Empl e2) {
        if(e1.getSalary() > e2.getSalary()){
            return 1;
        } else {
            return -1;
        }
    }
}

class Empl{
   
    private String name;
    private int salary;
   
    public Empl(String n, int s){
        this.name = n;
        this.salary = s;
    }
   
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getSalary() {
        return salary;
    }
    public void setSalary(int salary) {
        this.salary = salary;
    }
    public String toString(){
        return "Name: "+this.name+"-- Salary: "+this.salary;
    }
}

Comparable and Comparator

import java.util.Comparator;

public class Employee implements Comparable<Employee> {

    private int id;

    private String name;

    private int age;

    private long salary;

    public int getId() {

        return id;

    }

    public String getName() {

        return name;

    }

    public int getAge() {

        return age;

    }

    public long getSalary() {

        return salary;

    }

    public Employee(int id, String name, int age, int salary) {

        this.id = id;

        this.name = name;

        this.age = age;

        this.salary = salary;

    }

    @Override

    public int compareTo(Employee emp) {

        //let's sort the employee based on id in ascending order

        //returns a negative integer, zero, or a positive integer as this employee id

        //is less than, equal to, or greater than the specified object.

        return (this.id - emp.id);

    }

    @Override

    //this is required to print the user friendly information about the Employee

    public String toString() {

        return "[id=" + this.id + ", name=" + this.name + ", age=" + this.age + ", salary=" +

                this.salary + "]";

    }

}

/**

     * Comparator to sort employees list or array in order of Salary

     */

    public static Comparator<Employee> SalaryComparator = new Comparator<Employee>() {

        @Override

        public int compare(Employee e1, Employee e2) {

            return (int) (e1.getSalary() - e2.getSalary());

        }

    };

    /**

     * Comparator to sort employees list or array in order of Age

     */

    public static Comparator<Employee> AgeComparator = new Comparator<Employee>() {

        @Override

        public int compare(Employee e1, Employee e2) {

            return e1.getAge() - e2.getAge();

        }

    };

    /**

     * Comparator to sort employees list or array in order of Name

     */

    public static Comparator<Employee> NameComparator = new Comparator<Employee>() {

        @Override

        public int compare(Employee e1, Employee e2) {

            return e1.getName().compareTo(e2.getName());

        }

    };

.//sort employees array using Comparator by Salary

Arrays.sort(empArr, Employee.SalaryComparator);

System.out.println("Employees list sorted by Salary:\n"+Arrays.toString(empArr));

//sort employees array using Comparator by Age

Arrays.sort(empArr, Employee.AgeComparator);

System.out.println("Employees list sorted by Age:\n"+Arrays.toString(empArr));

//sort employees array using Comparator by Name

Arrays.sort(empArr, Employee.NameComparator);

System.out.println("Employees list sorted by Name:\n"+Arrays.toString(empArr))

import java.util.Comparator;

public class EmployeeComparatorByIdAndName implements Comparator {

    @Override

    public int compare(Employee o1, Employee o2) {

        int flag = o1.getId() - o2.getId();

        if(flag==0) flag = o1.getName().compareTo(o2.getName());

        return flag;

    }

}

import java.util.Arrays;

public class JavaObjectSorting {

    /**

     * This class shows how to sort custom objects array/list

     * implementing Comparable and Comparator interfaces

     * @param args

     */

    public static void main(String[] args) {

        //sorting custom object array

        Employee[] empArr = new Employee[4];

        empArr[0] = new Employee(10, "Mikey", 25, 10000);

        empArr[1] = new Employee(20, "Arun", 29, 20000);

        empArr[2] = new Employee(5, "Lisa", 35, 5000);

        empArr[3] = new Employee(1, "Pankaj", 32, 50000);

        

        //sorting employees array using Comparable interface implementation

        Arrays.sort(empArr);

        System.out.println("Default Sorting of Employees list:\n"+Arrays.toString(empArr));

        

        //sort employees array using Comparator by Salary

        Arrays.sort(empArr, Employee.SalaryComparator);

        System.out.println("Employees list sorted by Salary:\n"+Arrays.toString(empArr));

        

        //sort employees array using Comparator by Age

        Arrays.sort(empArr, Employee.AgeComparator);

        System.out.println("Employees list sorted by Age:\n"+Arrays.toString(empArr));

        

        //sort employees array using Comparator by Name

        Arrays.sort(empArr, Employee.NameComparator);

        System.out.println("Employees list sorted by Name:\n"+Arrays.toString(empArr));

        

        //Employees list sorted by ID and then name using Comparator class

        empArr[0] = new Employee(1, "Mikey", 25, 10000);

        Arrays.sort(empArr, new EmployeeComparatorByIdAndName());

        System.out.println("Employees list sorted by ID and Name:\n"+Arrays.toString(empArr));

    }

}

Array Sorting

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

public class JavaObjectSorting {

    /**

     * This class shows how to sort primitive arrays, 

     * Wrapper classes Object Arrays

     * @param args

     */

    public static void main(String[] args) {

        //sort primitives array like int array

        int[] intArr = {5,9,1,10};

        Arrays.sort(intArr);

        System.out.println(Arrays.toString(intArr));

        

        //sorting String array

        String[] strArr = {"A", "C", "B", "Z", "E"};

        Arrays.sort(strArr);

        System.out.println(Arrays.toString(strArr));

        

        //sorting list of objects of Wrapper classes

        List<String> strList = new ArrayList<String>();

        strList.add("A");

        strList.add("C");

        strList.add("B");

        strList.add("Z");

        strList.add("E");

        Collections.sort(strList);

        for(String str: strList) System.out.print(" "+str);

    }

}.

User Defined Object Sorting

public class ExampleComparator {

public static void main(String[] args) {

    List<Person> list = new ArrayList<Person>();

    list.add(new Person("shyam",24));

    list.add(new Person("jk",29));

    list.add(new Person("paul",30));

    list.add(new Person("ashique",4));

    list.add(new Person("sreeraj",14));

    for (Person person : list) {

        System.out.println(person.getName()+ "   "+ person.getAge());

    }

    Collections.sort(list,new PersonComparator());

    System.out.println("After sorting");

    for (Person person : list) {

        System.out.println(person.getName()+ "   "+ person.getAge());

    }

}

}

public class Person {

private int age;

private String name;

Person (String name, int age){

    setName(name);

    setAge(age);

}

public int getAge() {

    return age;

}

public void setAge(int age) {

    this.age = age;

}

public String getName() {

    return name;

}

public void setName(String name) {

    this.name = name;

}

}

public class PersonComparator implements Comparator<Person> {

@Override

public int compare(Person obj1, Person obj2) {

    return obj1.getAge() - obj2.getAge();

}

}

class Test {

    public int amount; //field u want to compare

    // ...

}

Write your custom comparator for this class:

class TestAmountComparator implements Comparator<Test> {

    @Override

    public int compare(Test t1, Test t2) {

        return Integer.valueOf(t1.amount).compareTo(Integer.valueOf(t2.amount))          

    }

}

To sort the list of your objects:

List<Test> list = new ArrayList<Test>(myTest); //your Test list

//sorting

Collections.sort(list, new TestAmountComparator()); //sort by amount

public class Person {

    private String name;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

}

public void someTest() {

    LinkedList<Person> persons = new LinkedList<Person>();

    persons.add(new Person());

    //add as many as you want

    Collections.sort(persons, new Comparator<Person>() {

        @Override

        public int compare(Person o1, Person o2) {

            return o1.getName().compareTo(o2.getName());

        }

    });

}

Xml SAX and DOM Parser

import java.io.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
import org.w3c.dom.*;

public class create {
public static void main(String[] args) throws Exception {
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter number to add elements in your XML file: ");
String str = bf.readLine();
int no = Integer.parseInt(str);
System.out.print("Enter root: ");
String root = bf.readLine();
DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        Document document = documentBuilder.newDocument();
Element rootElement = document.createElement(root);
        document.appendChild(rootElement);
for (int i = 1; i <= no; i++){
System.out.print("Enter the element: ");
String element = bf.readLine();
System.out.print("Enter the data: ");
String data = bf.readLine();
Element em = document.createElement(element);
em.appendChild(document.createTextNode(data));
rootElement.appendChild(em);
}
TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(document);
        StreamResult result =  new StreamResult(System.out);
StreamResult result1 =  new StreamResult("new.xml");
        transformer.transform(source, result);

transformer.transform(source, result1);
}
}import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class elecount {

  public static void main(String argv[]) {

try {

DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse("catalog.xml");

NodeList list = doc.getElementsByTagName("CD");

System.out.println("Total of elements : " + list.getLength());

} catch (ParserConfigurationException pce) {
pce.printStackTrace();
} catch (IOException ioe) {
ioe.printStackTrace();
} catch (SAXException sae) {
sae.printStackTrace();
}
  }
}import javax.xml.parsers.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;

public class elements{
public static void main(String[] args) {
try{
SAXParserFactory parserFact = SAXParserFactory.newInstance();
SAXParser parser = parserFact.newSAXParser();
System.out.println("XML Elements: ");
DefaultHandler handler = new DefaultHandler(){
public void startElement(String uri, String lName, String ele, Attributes attributes)throws SAXException{
//print elements of xml
System.out.println(ele);
}
};
parser.parse("catalog.xml", handler);
}
catch (Exception e){
e.printStackTrace();
}
}
}import org.w3c.dom.*;
import javax.xml.parsers.*;
import java.io.*;

public class getroot{
public static void main(String[] args) {
try{

File file = new File("catalog.xml");
if (file.exists()){
DocumentBuilderFactory fact = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = fact.newDocumentBuilder();
Document doc = builder.parse("catalog.xml");
Node node = doc.getDocumentElement();
String root = node.getNodeName();
System.out.println("Root Node: " + root);
}
else{
System.out.println("File not found!");
}
}
catch(Exception e){}
}
}import java.io.*;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;


public class readattr {
public static void main(String[] args) {
try {

File file = new File("catalog.xml");
if (file.exists()){
//SAX-implementation:
SAXParserFactory factory = SAXParserFactory.newInstance();
// Create SAX-parser
SAXParser parser = factory.newSAXParser();
System.out.println("Name:\t" + "Value:");
//Define a handler
SaxHandler handler = new SaxHandler();
// Parse the xml document
parser.parse(xmlFile, handler);
}
else{
System.out.println("File not found!");
}
}
catch (Exception e) {
e.printStackTrace();
}
}

private static class SaxHandler extends DefaultHandler {
public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXParseException,SAXException {
int length = attrs.getLength();
//Each attribute
for (int i=0; i // Get names and values to each attribute
String name = attrs.getQName(i);
System.out.print(name);
                String value = attrs.getValue(i);
System.out.println("\t"+value);
}
}
}
}import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;


public class readsax {


   public static void main(String argv[]) {


    try {

SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();

DefaultHandler handler = new DefaultHandler() {

boolean title = false;
boolean artist = false;
boolean company = false;
boolean price = false;
        boolean year = false;

public void startElement(String uri, String localName,String qName,
                Attributes attributes) throws SAXException {

System.out.println("Start Element :" + qName);

if (qName.equalsIgnoreCase("TITLE")) {
title = true;
}

if (qName.equalsIgnoreCase("ARTIST")) {
artist = true;
}

if (qName.equalsIgnoreCase("COMPANY")) {
company = true;
}

if (qName.equalsIgnoreCase("PRICE")) {
price = true;
}


if (qName.equalsIgnoreCase("YEAR")) {
year = true;
}

}

public void endElement(String uri, String localName,
String qName) throws SAXException {

System.out.println("End Element :" + qName);

}

public void characters(char ch[], int start, int length) throws SAXException {

if (title) {
System.out.println("Title : " + new String(ch, start, length));
title = false;
}

if (artist) {
System.out.println("Artist : " + new String(ch, start, length));
artist = false;
}

if (company) {
System.out.println("Company : " + new String(ch, start, length));
company = false;
}

if (price) {
System.out.println("Price : " + new String(ch, start, length));
price = false;
}


if (year) {
System.out.println("Year : " + new String(ch, start, length));
year = false;
}
}

     };

       saxParser.parse("catalog.xml", handler);

     } catch (Exception e) {
       e.printStackTrace();
     }

   }

}import java.io.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

public class readxml{
static public void main(String[] arg) {
try{
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter XML file name: ");
String xmlFile = bf.readLine();
File file = new File(xmlFile);
if (file.exists()){
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(xmlFile);
// Create transformer
Transformer tFormer = TransformerFactory.newInstance().newTransformer();
// Output text type
//tFormer.setOutputProperty(OutputKeys.METHOD, "text");
// Write the document to a file
Source source = new DOMSource(doc);
Result result = new StreamResult(System.out);
tFormer.transform(source, result);
}
else{
System.out.println("File not found!");
}
}
catch (Exception e){
System.err.println(e);
System.exit(0);
}
}
}import java.io.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

public class rmelement {
static public void main(String[] arg) {
try{
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter a XML file name: ");
String xmlFile = bf.readLine();
File file = new File(xmlFile);
System.out.print("Enter an element which have to delete: ");
String remElement = bf.readLine();
if (file.exists()){
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(xmlFile);
TransformerFactory tFactory = TransformerFactory.newInstance();
Transformer tFormer = tFactory.newTransformer();
Element element = (Element)doc.getElementsByTagName(remElement).item(0);
// Remove the node
element.getParentNode().removeChild(element);
//              Normalize the DOM tree to combine all adjacent nodes
doc.normalize();
Source source = new DOMSource(doc);
Result dest = new StreamResult(System.out);
tFormer.transform(source, dest);
System.out.println();
}
else{
System.out.println("File not found!");
}
}
catch (Exception e){
System.err.println(e);
System.exit(0);
}
}
}import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;
import java.io.*;

public class SearchElement{
public static void main(String[] args) {
try{
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter file name: ");
String str = bf.readLine();
File file = new File(str);
if (file.exists()){
DOMParser parser = new DOMParser();
parser.parse(str);
Document doc = parser.getDocument();
System.out.print("Enter element that have to count: ");
String ele = bf.readLine();
NodeList list = doc.getElementsByTagName(ele);
if(list.getLength() == 0){
System.out.println("Element doesn't exist in the " + str + " Document.");
}
else{
System.out.println("Element occurrs " + list.getLength() + " times in the " + str);
}
}
else{
System.out.println("File not found!");
}
}
catch (Exception e){
e.getMessage();
}
}
}
import org.w3c.dom.*;
import org.w3c.dom.Node;
import javax.xml.parsers.*;
public class totaltext{
    public static boolean isTextNode(Node n){
    return n.getNodeName().equals("#text");
  }
    public static void main(String[]args)throws Exception{
  DocumentBuilderFactory docFactory =  DocumentBuilderFactory.newInstance();
  DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
  Document doc = docBuilder.parse("catalog.xml");

          Element  root = doc.getDocumentElement();

System.out.println(root.getNodeName());        

 NodeList nl = root.getChildNodes();
 
         
for(int i=0; i            Node ele = nl.item(i);
            if(isTextNode(ele)){

           continue;
}
         
 System.out.print("\n\n"+ele.getNodeName()+":  ");
            System.out.println(ele.getFirstChild().getNodeValue()+"\t ");

 NodeList innernl= ele.getChildNodes();

            for(int j=0; j            Node node = innernl.item(j);
            if(isTextNode(node))
              continue;
            System.out.print("\n\n"+node.getNodeName()+":  ");
            System.out.print(node.getFirstChild().getNodeValue()+"\t ");
         


}
          System.out.println();
        }
    }
}

SOAP and Axis WebService Client

import java.net.URL;
import java.util.Vector;
import org.apache.soap.Constants;
import org.apache.soap.rpc.Call;
import org.apache.soap.rpc.Parameter;
import org.apache.soap.rpc.Response;

public class test {
  public static void main( String[] args ) throws Exception {
   // soap service endpoint
    URL url = new URL( "http://localhost:8080/soap/servlet/rpcrouter" );
    // create a call
   Call call = new Call();
    // Service uses standard SOAP encoding
    call.setEncodingStyleURI( Constants.NS_URI_SOAP_ENC );
    // Set service locator parameters
    call.setTargetObjectURI( "urn:ex" );
    call.setMethodName( "rstring" );
    // Create input parameter vector
    Vector params = new Vector();
    params.addElement( new Parameter( "s", String.class, "hai da...", null ) );
    call.setParams( params );
    // Invoke the service, note that an empty SOAPActionURI of
    // "" indicates that intent of the SOAP request is taken to
    // be the request URI
    Response resp = call.invoke( url, "" );

    // ... and evaluate the response
    if( resp.generatedFault() ) {
      throw new Exception();
    }
    else {
      // Call was successful. Extract response parameter and return result
      Parameter result = resp.getReturnValue();
      System.out.println( "temperature is -> " + result.getValue() );
    }
  }
}

import java.net.URL;

import java.util.Vector;

import org.apache.soap.Constants;

import org.apache.soap.Fault;

import org.apache.soap.rpc.Call;

import org.apache.soap.rpc.Parameter;

import org.apache.soap.rpc.Response;

public class test2{

public static void main(String args[])throws Exception{

System.out.println("hi how are you..");

Call call= new Call();

call.setEncodingStyleURI(Constants.NS_URI_SOAP_ENC);

call.setTargetObjectURI("urn:ex1");

Parameter param1=new Parameter("s",String.class,"99",null);

Vector paramlist=new Vector();

paramlist.addElement(param1);

call.setMethodName("convert");

call.setParams(paramlist);

URL url = new URL("http://localhost:8080/soap/servlet/rpcrouter");

Response result= call.invoke(url,"");

if(result.generatedFault()){

Fault f= result.getFault();

System.out.println(f.getFaultCode());

System.out.println(f.getFaultString());

}

else{

Parameter p=result.getReturnValue();

System.out.println(p.getValue());

}

}

}

/*

 * (#) ArithClient.java  Mar 19, 2012

 *

 */

import org.apache.axiom.om.*;

import org.apache.axis2.client.*;

import org.apache.axis2.addressing.*;

public class ArithClient {

  public static void main(String[] args) throws Exception {

    String wsdlDocument = "http://localhost:8080/axis2/services/arith?wsdl";

    EndpointReference targetEPR = new EndpointReference(wsdlDocument);

    OMFactory fac = OMAbstractFactory.getOMFactory();

    OMNamespace omNs = fac.createOMNamespace("http://arith", "arith");

    OMElement method = fac.createOMElement("add", omNs);

    OMElement paramOne = fac.createOMElement("a", omNs);

    paramOne.setText("12");

    method.addChild(paramOne);

    OMElement paramTwo = fac.createOMElement("b", omNs);

    paramTwo.setText("10");

    method.addChild(paramTwo);

    ServiceClient client = new ServiceClient();

    Options opts = new Options();

    opts.setTo(targetEPR);

    client.setOptions(opts);

    OMElement res = client.sendReceive(method);

    String result = res.getFirstElement().getText();

    System.out.println("Result: " + result);

  }

}

https://drive.google.com/open?id=0B_WUy8ODLamYd0p4YTNqQWFsRUU

Java Oracle Database Connectivity

import java.sql.*;
public class JdbcAccessCreate
{
 Connection con;
 Statement st;
 public JdbcAccessCreate()
 {
  try{
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc");
   System.out.println("Database Connected");
   st=con.createStatement();
   String query="create table student(roll number,name text,contactno number)";
    st.executeUpdate(query);
    System.out.println("Table created successfully");
    }catch(Exception e)
      {
      System.out.println("Error in connection"+e);
      }
  }
  public static void main(String arg[])
  {
    new JdbcAccessCreate();
    }
}
       import java.sql.*;
public class JdbcOracleCreate
{
 Connection con;
 Statement st;
 public JdbcOracleCreate()
 {
  try{
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
   System.out.println("Database Connected");
   st=con.createStatement();
   String query="create table student_xx(roll number(4),name varchar2(20),contactno number(10))";
    st.executeUpdate(query);
    System.out.println("Table created successfully");
    }catch(Exception e)
      {
      System.out.println("Error in connection"+e);
      }
  }
  public static void main(String arg[])
  {
    new JdbcOracleCreate();
    }
}
import java.sql.*;
import java.io.*;

public class JdbcOracleInsert
{
 Connection con;
 PreparedStatement pst;
 public JdbcOracleInsert()
 {
  try{
 char ch='y';
 while(ch=='y' || ch=='Y')
 {
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter roll");
int r=Integer.parseInt(br.readLine());
System.out.println("Enter name");
String nm=br.readLine();
System.out.println("Enter Contactno");
int ct=Integer.parseInt(br.readLine());
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
   System.out.println("Database Connected");
   pst=con.prepareStatement("insert into student_xx values(?,?,?)");
   pst.setInt(1,r);
   pst.setString(2,nm);
   pst.setInt(3,ct);
    pst.executeUpdate();
    System.out.println("Values inserted successfully\nDo u wish to insert more records");
    ch=(char)br.read();
}
    }catch(Exception e)
      {
      System.out.println("Error in connection"+e);
      }
  }
  public static void main(String arg[])
  {
    new JdbcOracleInsert();
    }
}
import java.sql.*;
import java.awt.*;
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
public class JdbcOracleInsertJF extends JFrame implements ActionListener
{
 Connection con;
 int r,ct1;
 String nm;
 PreparedStatement pst;
 JLabel l1,l2,l3;
 JTextField t1,t2,t3;
 JButton b;
 JPanel p,p1,mp;
 public JdbcOracleInsertJF()
 {
  l1=new JLabel("Roll");
  l2=new JLabel("Name");
  l3=new JLabel("DOB");
  t1=new JTextField(20);
  t2=new JTextField(20);
  t3=new JTextField(20);
  b=new JButton("Insert");
  b.addActionListener(this);
  p=new JPanel(new GridLayout(3,2));
  p.add(l1);
  p.add(t1);
  p.add(l2);
  p.add(t2);
  p.add(l3);
  p.add(t3);
  p1=new JPanel();
  p1.add(b);
  mp=new JPanel(new GridLayout(2,1));
 mp.add(p);
 mp.add(p1);
 Container ct=getContentPane();
      ct.setLayout(new FlowLayout());
      ct.add(mp);
        setTitle("Demo");
          setSize(400,400);
         setVisible(true);

  try{

   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
JOptionPane.showMessageDialog(this,"Database Connected");
   pst=con.prepareStatement("insert into student_xx values(?,?,?)");
  }catch(Exception e)
      {
      System.out.println("Error in connection"+e);
      }
  }
      public void actionPerformed(ActionEvent ae)
      {
 try{
 r=Integer.parseInt(t1.getText());
 nm=t2.getText();
ct1=Integer.parseInt(t3.getText());
pst.setInt(1,r);
pst.setString(2,nm);
pst.setInt(3,ct1);
pst.executeUpdate();
JOptionPane.showMessageDialog(this,"Record inserted ");
}catch(Exception e)
      {
     JOptionPane.showMessageDialog(this,"Error is "+e);
      }

   }
  public static void main(String arg[])
  {
    new JdbcOracleInsertJF();
    }
}
import java.sql.*;
public class JdbcOracleSelect
{
 Connection con;
 Statement st;
 ResultSet rs;
 public JdbcOracleSelect()
 {
  try{
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
   System.out.println("Database Connected");
   st=con.createStatement();
   String query="select * from stud_ash";
    rs=st.executeQuery(query);
    System.out.println("Roll \t Name \t Cont No.");
    while(rs.next())
    {
System.out.println(rs.getInt(1)+"\t"+rs.getString(2)+"\t"+rs.getString(3));
}
    }catch(Exception e)
      {
      System.out.println("Error in connection"+e);
      }
  }
  public static void main(String arg[])
  {
    new JdbcOracleSelect();
    }
}
import java.sql.*;
import java.awt.*;
import java.io.*;
import javax.swing.*;
import javax.swing.table.*;
import java.awt.event.*;
import java.util.*;
public class JdbcOracleSelectAll extends JFrame implements ActionListener
{
 Connection con;
  ResultSet rs;
 Statement st;
ResultSetMetaData rsmd;
 JLabel l1,l2;
 JTable jtab;
 JScrollPane jsp;
 JTextField t1;
 JButton b_execute;
 JPanel p1,p2,mp;
 Vector head,row,data;
 public JdbcOracleSelectAll()
 {
  l1=new JLabel("SQL");
  l2=new JLabel("Details are");
   t1=new JTextField(20);
  b_execute=new JButton("Execute");
  b_execute.addActionListener(this);
  p1=new JPanel();
  jtab=new JTable();
  int vsp=ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS;
  int hsp=ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS;
  jsp=new JScrollPane(jtab,vsp,hsp);

  p1.add(l1);
  p1.add(t1);
  p1.add(b_execute);
  p2=new JPanel();
  p2.add(l2);
  p2.add(jsp);
  mp=new JPanel();
 Container ct=getContentPane();

      ct.add(p1,BorderLayout.NORTH);
      ct.add(p2,BorderLayout.CENTER);
        setTitle("Demo");
          setSize(550,400);
         setVisible(true);

  try{

   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
JOptionPane.showMessageDialog(this,"Database Connected");
  }catch(Exception e)
      {
    JOptionPane.showMessageDialog(this,"Error in connection"+e);
      }
}
  public Vector displayData(String query)
  {
 try{
 st=con.createStatement();
 rs=st.executeQuery(query);
rsmd=rs.getMetaData();
 int cols=rsmd.getColumnCount();
 head=new Vector();
 for(int i=1;i<=cols;i++)
  {
  head.add(rsmd.getColumnName(i));
  }
  data=new Vector();
  data.add(head);
  while(rs.next())
  {
  row=new Vector();
for(int i=1;i<=cols;i++)
  {
  row.add(rs.getString(i));
  }
  data.add(row);
  }

 }catch(Exception e)
 {
 head=new Vector();
 head.add("No data found");
 data=new Vector();
 data.add(head);
      }
      return data;
}
   public void actionPerformed(ActionEvent ae)
      {
 if(ae.getSource()==b_execute)
 {

try
{

String query=t1.getText();
data=displayData(query);
head=(Vector)data.elementAt(0);
data.removeElementAt(0);
DefaultTableModel dtm=new DefaultTableModel(data,head);
jtab.setModel(dtm);

}catch(Exception e)
 {
    JOptionPane.showMessageDialog(this,"Error in execute "+e);
 }
}
}

  public static void main(String arg[])
  {
    new JdbcOracleSelectAll();
    }
}
import java.sql.*;
import java.awt.*;
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
public class JdbcOracleSelectJF extends JFrame implements ActionListener
{
 Connection con;
  ResultSet rs;
 Statement st;
  PreparedStatement pst;
 JLabel l1,l2,l3;
 JTextField t1,t2,t3;
 JButton b_insert,b_first,b_next,b_pre,b_last,b_clear;
 JPanel p,p1,p2,mp;
 public JdbcOracleSelectJF()
 {
  l1=new JLabel("Roll");
  l2=new JLabel("Name");
  l3=new JLabel("Contactno");
  t1=new JTextField(20);
  t2=new JTextField(20);
  t3=new JTextField(20);
  b_insert=new JButton("Insert");
  b_insert.addActionListener(this);
  b_first=new JButton("  <<  ");
    b_first.addActionListener(this);
  b_pre=new JButton("  <  ");
    b_pre.addActionListener(this);
  b_next=new JButton("  >  ");
    b_next.addActionListener(this);
    b_last=new JButton("  >>  ");
 b_last.addActionListener(this);
 b_clear=new JButton(" Clear");
 b_clear.addActionListener(this);
    p=new JPanel(new GridLayout(3,2));
  p.add(l1);
  p.add(t1);
  p.add(l2);
  p.add(t2);
  p.add(l3);
  p.add(t3);
  p1=new JPanel();
  p1.add(b_insert);
  p1.add(b_clear);
  p2=new JPanel();
  p2.add(b_first);
  p2.add(b_pre);
  p2.add(b_next);
  p2.add(b_last);
  mp=new JPanel(new GridLayout(3,1));
 mp.add(p);
 mp.add(p1);
 mp.add(p2);
 Container ct=getContentPane();
      ct.setLayout(new FlowLayout());
      ct.add(mp);
        setTitle("Demo");
          setSize(550,400);
         setVisible(true);

  try{

   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   con=DriverManager.getConnection("jdbc:odbc:abc","scott","tiger");
JOptionPane.showMessageDialog(this,"Database Connected");
   st=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
  rs=st.executeQuery("select * from student_xx");
  }catch(Exception e)
      {
    JOptionPane.showMessageDialog(this,"Error in connection"+e);
      }
}
  public void display()
  {
 try{
 t1.setText(""+rs.getInt(1));
 t2.setText(""+rs.getString(2));
 t3.setText(""+rs.getInt(3));
 }catch(Exception e)
 {
 JOptionPane.showMessageDialog(this,"Error in display "+e);
      }
}
   public void actionPerformed(ActionEvent ae)
      {
 if(ae.getSource()==b_clear)
 {
 t1.setText("");
 t2.setText("");
 t3.setText("");
 t1.requestFocus();
 }
if(ae.getSource()==b_insert)
{
try
{
int r=Integer.parseInt(t1.getText());
String nm=t2.getText();
int ct=Integer.parseInt(t3.getText());
pst=con.prepareStatement("insert into student_xx values(?,?,?)");
pst.setInt(1,r);
pst.setString(2,nm);
pst.setInt(3,ct);
pst.executeUpdate();
JOptionPane.showMessageDialog(this,"Record inserted successfully");
}catch(Exception e)
 {
    JOptionPane.showMessageDialog(this,"Error in insert "+e);
 }
}
 if(ae.getSource()==b_first)
 {
try{
rs.first();
display();

}catch(Exception e)
     {
    JOptionPane.showMessageDialog(this,"Error in first  "+e);
     }
 }
       if(ae.getSource()==b_pre)
   {
  try{
if(rs.previous()==false)
  {
JOptionPane.showMessageDialog(this,"This is the 1st Record of File ");
}else

  display();

 }catch(Exception e)
       {
      JOptionPane.showMessageDialog(this,"Error in pre "+e);
      }
  }
       if(ae.getSource()==b_next)
   {
  try{
  if(rs.next()==false)
  {
JOptionPane.showMessageDialog(this,"This is the Last Record ");
}else
  display();

 }catch(Exception e)
       {
      JOptionPane.showMessageDialog(this,"Error in next "+e);
      }
  }
  if(ae.getSource()==b_last)
     {
    try{
    rs.last();
    display();

   }catch(Exception e)
         {
        JOptionPane.showMessageDialog(this,"Error in last "+e);
        }
  }
}
  public static void main(String arg[])
  {
    new JdbcOracleSelectJF();
    }
}