How to open notepad using java program

Posted by: Instanceofjava Posted date: July 22, 2016 / comment : 0 ,

  • Notepad is a text editor from windows operating system. We use notepad for writing text files.
  • We can open a new notepad using java code.
  • By using the concept of running another application by Runtime class in java.
  • By creating object of runtime and calling  exec() method by passing application name.
  • Lets see how to open a notepad using java code




Program #1: Java example program to open notepad


  1. package interestingJavaprograms;
  2. import java.io.IOException;
  3.  
  4. public class NotepadJava {
  5.  
  6.     /**
  7.      * @ www.instanceofjava.com
  8.      * @ how to open a new notepad using java program
  9.      */
  10. public static void main(String[] args) {
  11.        
  12.           Runtime rt = Runtime.getRuntime();
  13.           
  14. try {
  15.       rt.exec("notepad");
  16. }
  17.  catch (IOException ex) {
  18.  
  19.  System.out.println(ex);
  20.  
  21. }  
  22.  
  23. }
  24.  
  25. }

 Output:

open notepad using java


Program #2: Java example program to open notepad and after 2 seconds close it.
  1. package interestingJavaprograms;
  2. import java.io.IOException;
  3.  
  4. public class NotepadJava {
  5.  
  6.     /**
  7.      * @ www.instanceofjava.com
  8.      * @ how to open a new notepad using java program
  9.      */
  10. public static void main(String[] args) throws InterruptedException, IOException {
  11.         
  12. Runtime runTime = Runtime.getRuntime();
  13. System.out.println("Opening notepad");
  14. Process process = runTime.exec("notepad");
  15.           
  16. try {
  17.  
  18.  
  19. Thread.sleep(200); 

  21.  process.destroy();
  22.  System.out.println("Closing notepad");
  23.  
  24. }
  25.  catch (Exception ex) {
  26.  
  27.  System.out.println(ex);
  28.  
  29. }  
  30.  
  31. }
  32.  
  33. }

  • We can open already existing notepad also for that we need to specify notepad.exe location and path of the destination file.
  • We need to pass these two parameters  to exec method of runtime class.
  • runTime.exec("C:\\Windows\\System32\\notepad.exe E:\\Samplenotepad.txt");

Program #3: Java example program to open exiting notepad txt file.


  1. package interestingJavaprograms;
  2. import java.io.IOException;
  3.  
  4. public class NotepadJava {
  5.  
  6.     /**
  7.      * @ www.instanceofjava.com
  8.      * @ how to open a new notepad using java program
  9.      */
  10. public static void main(String[] args) {
  11.        
  12.           Runtime rt = Runtime.getRuntime();
  13.           
  14. try {
  15.    runTime.exec("C:\\Windows\\System32\\notepad.exe E:\\Samplenotepad.txt");
  16. }
  17.  catch (IOException ex) {
  18.  
  19.  System.out.println(ex);
  20.  
  21. }  
  22.  
  23. }
  24.  
  25. }

Java program to remove vowels from string java

Posted by: Instanceofjava Posted date: July 17, 2016 / comment : 0 ,

  • java program to remove vowels from a string
  • To remove vowels from a string we can use predefined method of string  replaceAll()
  • By passing all vowels to the method replaceAll() with empty it will replaces all vowels with empty. 
  • Check below topic for more programs on string 
  • Java Experience interview programs on strings



 Program #1: Java example program to remove all vowels from a String



  1. package inheritanceInterviewPrograms;
  2. public class RemoveVowels {
  3.  
  4.     /**
  5.      * @www.instanceofjava.com 
  6.      * @String interview programs asked in interviews
  7.      * @Remove vowels from a string in java
  8.      */
  9.  
  10.  public static void main(String[] args) {
  11.  
  12.         String str = "RemoveVowels";
  13.         String resustr = str.replaceAll("[aeiouAEIOU]", "");
  14.         System.out.println(resustr);
  15.  
  16.     }
  17.  
  18. }

 Output:


  1. RmvVwls

Program #2: Java example program to remove all vowels from a String by taking input from user
remove vowels from string

Java program to reverse vowels of a string

Posted by: Instanceofjava Posted date: July 17, 2016 / comment : 0 ,


Program : Java example program to Reverse Vowels  in a String



  1. package inheritanceInterviewPrograms;
  2. /*
  3.  * @www.instanceofjava.com
  4.  */
  5. public class ReverseVowels {
  6.     public static String reverseVowels(String string) {
  7.  
  8.         String vowelsStr = "aeiouAEIOU";
  9.  
  10.         int lo = 0;
  11.         int hi = string.length() - 1;
  12.         char[] ch = string.toCharArray();
  13.  
  14.  while (lo < hi) {
  15.  
  16.      if (!vowelsStr.contains(String.valueOf(string.charAt(lo)))) {
  17.                 lo++;
  18.                 continue;
  19.        }
  20.  
  21.     if (!vowelsStr.contains(String.valueOf(string.charAt(hi)))) {
  22.                 hi--;
  23.                 continue;
  24.        }
  25.  
  26.     // swaping variables
  27.      swap(ch, lo, hi);
  28.             lo++;
  29.             hi--;
  30.       }
  31.  
  32.         return String.valueOf(ch);
  33.     }
  34.  
  35. private static void swap(char[] ch, int lo, int hi) {
  36.  
  37.         char temparray = ch[lo];
  38.         ch[lo] = ch[hi];
  39.         ch[hi] = temparray;
  40.  
  41.  }
  42.     
  43. public static void main (String args[]) {
  44.         
  45.          
  46.  System.out.println("After reversing vowels in a string="reverseVowels("InstanceOfjava"));
  47.         
  48.          
  49. }
  50.  
  51. }
Output:


  1. After reversing vowels in a string=anstancOefjavI


Core java online programming test on inheritance

Posted by: Instanceofjava Posted date: July 17, 2016 / comment : 0 , ,

  • Inheritance means getting properties from one class object to another.
  • So in sub class we can use or access super class variables and method : re usability
  • There are some interesting and important points to discuss about inheritance
  • In major java interviews and java online test on core java there is more chance of getting programming questions from inheritance
  • So let us see some java test questions. java test online to practice
  • If you want explanations then visit below topic
  • Top 16 Java Inheritance Interview questions for freshers and experienced  




5 Points to know about inheritance:

Program #1: Java test on inheritance:
  • Creating object for super class and calling super class methods and accessing super class variables.

  1. package interviewprograms.instanceofjava;
  2. public class Super{
  3.  
  4.  int a, int b;
  5.  
  6. void show(){
  7.  System.out,println("Inside Show method");
  8. }
  9.  
  10. }



  1. package interviewprograms.instanceofjava;
  2. public class Sub extends Super{
  3.  int a, int b;
  4. public static void main(String[] args) {
  5.         
  6. Super obj= new Super();
  7. obj.a=10;
  8. System.out,println(obj.a);
  9.  obj.show();
  10. }
  11. }






Program #2: Core Java online test on inheritance:
  • Creating object for sub class and calling sub class methods and accessing sub class variables.

  1. package interviewprograms.instanceofjava;
  2. public class Super{
  3.  
  4.  int a, int b;
  5.  
  6. void show(){
  7.  System.out,println("Inside Show method");
  8. }
  9.  
  10. }

  1. package interviewprograms.instanceofjava;
  2.  
  3. public class Sub extends Super{
  4.  int x;
  5.  
  6.  
  7. void show(){
  8.  System.out,println("Inside Sub class Show method");
  9. }
  10. public static void main(String[] args) {
  11.         
  12. Sub obj= new Sub ();
  13. obj.x=10;
  14. System.out,println(obj.x);
  15.  obj.show();
  16. }
  17. }





Program #3: core java online test for beginners and experienced on inheritance
  • Creating object for sub class accessing super class members and sub class members.

  1. package interviewprograms.instanceofjava;
  2. public class Super{
  3.  
  4.  int a, int b;
  5.  
  6. void show(){
  7.  System.out,println("Inside Show method");
  8. }
  9.  
  10. void print(){
  11.  System.out,println("Inside super class print method");
  12. }
  13.  
  14. }

  1. package interviewprograms.instanceofjava;
  2.  
  3. public class Sub extends Super{
  4.  int x;
  5.  
  6.  
  7. void show(){
  8.  System.out,println("Inside Sub class Show method");
  9. }
  10. void msg(){
  11.  System.out,println("Inside Sub class msg method");
  12. }
  13. public static void main(String[] args) {
  14.         
  15. Sub obj= new Sub ();
  16. obj.x=10;
  17. System.out,println(obj.x);
  18.  obj.show();
  19. obj.print();
  20. }
  21. }







Program #4: core java online test for beginners and experienced on inheritance
  • Creating object for sub class and assigning to super class reference.

  1. package interviewprograms.instanceofjava;
  2. public class Super{
  3.  
  4.  int a, int b;
  5.  
  6. void show(){
  7.  System.out,println("Inside Show method");
  8. }
  9.  
  10. void print(){
  11.  System.out,println("Inside super class print method");
  12. }
  13.  
  14. }


core java online test for beginners






Program #5: core java online test for beginners and experienced on inheritance

  • Creating object for sub class and assigning to super class reference and calling sub class method.
  1. package interviewprograms.instanceofjava;
  2. public class Super{
  3.  
  4.  int a, int b;
  5.  
  6. void show(){
  7.  System.out,println("Inside Show method");
  8. }
  9.  
  10. void print(){
  11.  System.out,println("Inside super class print method");
  12. }
  13.  
  14. }


  1. package interviewprograms.instanceofjava;
  2.  
  3. public class Sub extends Super{
  4.  int x;
  5.  
  6.  
  7. void show(){
  8.  System.out,println("Inside Sub class Show method");
  9. }
  10.  
  11. void msg(){
  12.  System.out,println("Inside Sub class msg method");
  13. } 
  14.  
  15. public static void main(String[] args) {
  16.         
  17. Super obj= new Sub (); 
  18. obj.msg();
  19. }
  20. }





 EnJoY LeArNinG  WitH Us...

Java interview questions to practice

Posted by: Instanceofjava Posted date: July 17, 2016 / comment : 0 ,

  • We have provided some java interview programming questions for freshers and experienced candidates.
  • So please try to answer these java interview questions and practice.
  • If you have any doubt go through the given explanation link you can get the answer for that.
  • Still if  you need any clarifications feel free to contact us. Skype/Gmail: instanceofjava




Program #1: what will happen if we try to interchange modifiers of main method

  1. package interviewprograms.instanceofjava;
  2. public class InterviewProgram {
  3.  
  4. /**
  5. * @java interview programming  questions and answers for freshers and experienced
  6.  */
  7.   
  8. static public void main(String[] args) {
  9.         
  10.         System.out.println("Hello world");
  11.  
  12.     }
  13. }





Program #2:Do you know about static in java . How static works?
java interview questions for experienced candidates





Program #3:Java Interview question on try catch block in java

  1. package interviewprograms.instanceofjava;
  2. public class InterviewProgram {
  3.  
  4. /**
  5. * @java interview programming  questions and answers for freshers and experienced
  6.  */
  7.   
  8. public static void main(String[] args) {
  9.         
  10.  try {
  11.  
  12.             System.out.println("I am try block");
  13.             
  14. } finally {
  15.  
  16.             System.out.println("I am finally block");        }
  17.  
  18. }
  19. }







Program #4:Java Interview question on what happens when we print object
  1. package interviewprograms.instanceofjava;
  2. public class InterviewProgram {
  3.  
  4. /**
  5. * @java interview programming  questions and answers for freshers and experienced
  6.  */
  7.   
  8. public static void main(String[] args) {
  9.         
  10.  try {
  11.  
  12.             System.out.println("I am try block");
  13.             
  14. } finally {
  15.  
  16.             System.out.println("I am finally block");        }
  17.  
  18. }
  19. }





Java programming interview questions and answers for experienced

Posted by: Instanceofjava Posted date: July 16, 2016 / comment : 1 ,

  • Here some of the java programming interview questions and answers for experienced on different topics.
  • Java interview programs and answers for experienced.
  • Java Coding interview Questions
  • Java tricky interview programs to practice.




 Program #1: what will happen if we try to print null using system.out.println

  1. package interviewprograms.instanceofjava;
  2. public class InterviewProgram {
  3.  
  4.     /**
  5.      * @java programming interview questions and answers for freshers and experienced
  6.      */
  7.     public static void main(String[] args) {
  8.         
  9.         System.out.println(null);
  10.  
  11.     }
  12.  
  13. }






Program #2: Java Interview program :Can we create object for abstract class in same class

  1. package interviewprograms.instanceofjava;
  2. public abstract class AbstractDemo {
  3.  
  4. public static void main(String args[]){
  5.         
  6.         AbstractDemo obj = new AbstractDemo();
  7.         
  8.  }
  9.  
  10. }





Program #3: Java Interview program : what will be the output of below java program


Java programming interview questions and answers for experienced





 Program #4: Guess the order of execution of constructors

  1. package interviewprograms.instanceofjava;
  2. public class ConstructorDemo {
  3.  
  4. ConstructorDemo(){
  5.         this(1);
  6.         System.out.println("Zero argument constructor");
  7. }
  8.     
  9. ConstructorDemo(int a){
  10.         this("Hi",1);
  11.         System.out.println("One argument constructor");
  12. }
  13.  
  14. ConstructorDemo(String str, int x){
  15.     
  16.         System.out.println("Two argument constructor");
  17. }
  18.  
  19. public static void main(String[] args) {
  20.  
  21.         ConstructorDemo obj =new ConstructorDemo();
  22.  
  23.     }
  24.  
  25. }





Super keyword java programs for interview for freshers and experienced

Posted by: Instanceofjava Posted date: July 16, 2016 / comment : 0 ,

  • Lets see some interesting java programs on super keyword.
  • Basically super keyword used to refer super class methods and variables. So now let us see how super will work in some scenarios. lets practice.
  • Try to answer below java programming interview questions for beginners. 
  • Java programs asked in technical interview for freshers and experienced.




Program #1: What will be the output of below java program

  1. package com.superkeywordinjava;
  2.  public Class SuperDemo{ 
  3.  
  4. int a,b;
  5.  
  6. }

  1. package com.superkeywordinjava;
  2. public Class Subdemo extends SuperDemo{ 
  3. int a,b;
  4. void disply(){

  6. super.a=10;
  7. super.b=20;
  8.  
  9. System.out.println(a);
  10. System.out.println(b);
  11. System.out.println(super.a);
  12. System.out.println(super.b);
  13.  
  14. }
  15.  
  16. public static void main (String args[]) {
  17.  Subdemo obj= new Subdemo();
  18.  
  19. obj.a=1;
  20. obj.b=2;
  21.  
  22. obj.disply();
  23.  

  25.  
  26. }
  27. }






Program #2: What will be the output of below java program


super keyword java interview programs for freshers





Program #3: Basic java programs for interview on super keyword

  1. package com.superinterviewprograms;
  2. public Class SuperDemo{ 
  3.  
  4. int a,b;
  5.  
  6. SuperDemo(int x, int y){
  7.  a=x;
  8. b=y
  9. System.out.println("Super class constructor called ");
  10. } 
  11.  
  12.  
  13. }

  1. package com.superinterviewprograms;
  2.  
  3. public Class Subdemo extends SuperDemo{ 
  4.  
  5. int a,b;
  6.  
  7. SubDemo(int x, int y){
  8. super(10,20);
  9.  a=x;
  10. b=y
  11. System.out.println("Sub class constructor called ");
  12. }
  13.  
  14. public static void main (String args[]) {
  15.  Subdemo obj= new Subdemo(1,2);

  17.  
  18. }
  19. }





Program #4: Java interview Program on super keyword

  • What will happen if our class constructor having super() call but our class not extending any class.

  1. package com.superinterviewprograms;
  2.  
  3. public Class Sample{ 
  4.  
  5. Sample(){
  6. super();
  7. System.out.println("Sample class constructor called "); 
  8.  
  9. }
  10.  
  11. public static void main (String args[]) {
  12.  
  13.  Sample obj= new Sample();
  14.  
  15. }
  16. }





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