Custom exception handling example in java

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
for(int i=0;i<10;i++){
try{
System.out.println("The value is " +i);

if(i==0){
Myexception m = new Myexception("Less than 10");
throw m;
}
}
catch(Myexception m){
m.printStackTrace();

}
finally{
System.out.println("I am in final block");
}
}
}

}

public class Myexception extends Exception {

String j;

Myexception(){

System.out.println("Default constructed");

}

Myexception(String i){

super(i);

}

}

output:-

The value is 0

Myexception: Less than 10

at First.main(First.java:11)

I am in final block

The value is 1

I am in final block

The value is 2

I am in final block

The value is 3

I am in final block

The value is 4

I am in final block

The value is 5

I am in final block

The value is 6

I am in final block

The value is 7

I am in final block

The value is 8

I am in final block

The value is 9

I am in final block

Exception handling example in java (ArrayIndexOutOfBoundsException exception handling)

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
Second obj = new Second();
obj.S();
}

}

public class Second {

int i[]=new int[5];

   void S(){

try{  i[7]=2;}

catch (ArrayIndexOutOfBoundsException a){

a.printStackTrace();

System.out.println("Catch Block.....");

}

finally{

 

System.out.println("Final Block .....");

}

  

   }

}

output:-

java.lang.ArrayIndexOutOfBoundsException: 7

at Second.S(Second.java:6)

at First.main(First.java:7)

Catch Block.....

Final Block .....

Exception handling example in java

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
try{
int k = args.length;
int i = Integer.parseInt(args[0]);
int j = Integer.parseInt(args[1]);
Sec obj = new Sec();
obj.sum(i, j);
}

catch(ArrayIndexOutOfBoundsException a){

a.printStackTrace();
System.out.println("Please pass runtime arguments while executing the program");
}
finally{
System.out.println("Finally block");
}
}
}


public class Sec {
void sum(int i,int j){
int k = i+j;
System.out.println("The value is " +k);
}
}

output:-

java.lang.ArrayIndexOutOfBoundsException: 0

at First.main(First.java:8)

Please pass runtime arguments while executing the program

Finally block

Java Checked Exception example

import java.io.*;
public class First {

public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
System.out.println("Enter your number");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int i = Integer.parseInt(br.readLine());
System.out.println("The value of \"i\" is " +i);
}
}

output:-

Enter your number

10

The value of "i" is 10

Java Interface example

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
Third obj = new Second();
Four obj1 = new Second();
obj.F();
obj.S();
obj1.F();
obj1.M();
obj1.S();
obj1.T();
}

}

public class Second implements Four {

public void F(){

System.out.println("F");

}

public void S(){

System.out.println("S");

}

public void T(){

System.out.println("T");

}

public void M(){

System.out.println("M");

}

}

public interface Third {

void F();

void S();

}

interface Four extends Third{

void T();

void M();

}

output:-

F

S

F

M

S

T

Interface example in java

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
Second obj = new Third();
obj.display();
obj.fine();
}

}

public interface Second {

void display();

void fine();

}

public class Third implements Second{

public void display(){

System.out.println("One");

}

public void fine(){

System.out.println("Two");

}

}

output:-

One

Two

Abstract class example 2

public class First {

public static void main(String[] args) {
// TODO Auto-generated method stub
Third obj = new four();
obj.First();
obj.like();
obj.display();
}

}

public class Second {

void display(){

System.out.println("Testing display");

}

}

abstract class Third extends Second{

abstract void First();

void like(){

System.out.println("like");

}

}

class four extends Third{

void First(){

System.out.println("Testing Third Display");

}

}

output:-

Testing Third Display

like

Testing display