Question

2. Write a java program that implements bank trancations using user deined exception 3. Write a java program to identify the significance of finally block in handling exceptions. 4. Write a java program to generate multiple threads of creating clock pulses.(using runnable interface)

Answer 1

1. Bank Transactions using user defined exception.

Source code:-

import java.util.Scanner;
import java.lang.Exception;   
import java.util.Random;

class MyException extends Exception
{
MyException(String message)
{
super(message);
}
}
interface Account
{
void CreateAcc();
void Deposit();
void Withdraw();
}

class Bank extends BankUtilities implements Account
{
  
  
void getInfo()
{
try
{   
System.out.print("Enter Name Of the Acc Holder: "); //Enter Name Of the Acc Holder:
name=in.nextLine();
  
  
System.out.print("Enter SSN: "); //Enter SSN:
ssn=in.nextInt();
  
in.nextLine();
System.out.print("Enter Your Location: ");
loc=in.nextLine();
  
System.out.println("Mention your account type: \n 1.Savings\n 2.Current ");
acctype=in.nextInt();
switch(acctype)
{
case 1:
System.out.println("Enter the initial amount of deposit:");
temp=in.nextFloat();
if(temp<0)
{
System.out.println("Invalid Amount\nTry again:\n");
System.out.println("Enter the initial amount of deposit:");
temp=in.nextFloat();
}
Deposit(temp);
System.out.println("Enter no.of years:");
year=in.nextInt();
if(year<=0)
{
System.out.println("Invalid year\n Try again.");
System.out.println("Enter no.of years:");
year=in.nextInt();
}
break;
case 2:
System.out.println("Enter the initial amount of deposit:");
temp=in.nextFloat();
if(temp<0)
{
System.out.println("Invalid Amount\nTry again:\n");
System.out.println("Enter the initial amount of deposit:");
temp=in.nextFloat();
}
Deposit(temp);
break;
default: System.out.println("Choose correct Option");
} //Switch
}
catch(Exception e)
{
System.out.println("Inbuilt Exception "+e);
System.exit(0);
}
  
}//Get Information
  
public void CreateAcc() //New account creation
{
try
{
getInfo();
System.out.println("\nYour Account is Successfully Created!");
accnum=rnd.nextInt(1000)+1;
System.out.println("Hello "+name+" your account no is " +accnum+".\n");
}
catch(Exception e)
{
System.out.println("Fatal Error");
}
}
  
//Deposit
void Deposit(double temp) // Initial Deposit
{
try
{
if(temp>500) //throws exception when deposited amount is less than 500
{
bal+=temp;
System.out.println("SUCCESSFULLY CREDITED");
}
else
{
throw new MyException("Minimum Deposit Violation");
}
}
catch(MyException e)
{
System.out.println(e.getMessage());
System.out.println("TRANSACTION FAILURE");
System.exit(0);
}
  
}
  
public void Deposit() // regular deposit
{
  
System.out.println("Enter the amount to be deposited :");
temp=in.nextFloat();
try
{
if(temp>0)
{
bal+=temp;
System.out.println("SUCCESSFULLY CREDITED");
}
else
{
throw new MyException("INVALID AMOUNT EXCEPTION");
}
}
catch(MyException e)
{
System.out.println(e.getMessage());
System.out.println("TRANSACTION FAILURE");
}
  
}

//Withdraw
public void Withdraw() // For Withdraw the money
{
  
System.out.println("Enter the amount to be withdrawn :");
temp=in.nextFloat();
if(temp<=0)
{
System.out.println("Invalid Amount Error.");
System.exit(0);
}

try
{
  
if(temp<bal)
{
bal-=temp;
System.out.println("SUCCESSFULLY DEBITED");
}
else
{
throw new MyException("INSUFFIECEINT FUND EXCEPTION");
}
}
catch(MyException e)
{
System.out.println(e.getMessage());
System.out.println("TRANSACTION FAILURE");
}
  
}
  
//Checking Balance
void CheckBal() //To check the balance
{
System.out.println("Your Balance is :"+bal);
}
  
}

// Main class
class BankDemoException
{
public static void main(String arg[]) throws MyException
{
Scanner in = new Scanner(System.in);
Bank b = new Bank();

System.out.println("\n\n\t- - -Menu - - -");
try
{
while(true)
{
System.out.println(" 1.Create A New Account \n 2.Deposit Money \n 3.Check The remaining Balance \n 4.Withdraw \n 5.Exit.");
int ch = in.nextInt();
switch(ch)
{
case 1:
b.CreateAcc();
break;
  
case 2:
b.Deposit();
break;

case 3:
b.CheckBal();
break;   
  
case 4:
b.Withdraw();
break;

  
case 5:
System.exit(0);
break;
  
default: System.out.println("Enter correct option");
}
}
}
catch(Exception e)
{
System.out.println("exception "+e);
}
}
}

class BankUtilities
{
int acctype,year=1,ssn=0,accnum;
float intr;
String name="";
String loc="";
Scanner in = new Scanner(System.in);
Random rnd = new Random();
double temp=0.0,bal=0.0;
  
}

output of above program:-

C:\Users\VenkateshEmmandi\Desktop>java BankDemoException - - - Menu - - - 1. Create A New Account 2.Deposit Money 3. Check The remaining Balance 4.Withdraw 5. Exit. Enter Name of the Acc Holder: vinod Enter SSN: 678 Enter Your Location: india Mention your account type: 1. Savings 2. Current 9000 SUCCESSFULLY CREDITED Enter no.of years: Your Account is Successfully created! Hello vinod your account no is 789. 1. Create A New Account 2. Deposit Money 3. Check The remaining Balance 4.Withdraw 5. Exit. Your Balance is :9000.0 1. Create A New Account 2.Deposit Money 3.Check The remaining Balance 4.Withdraw 5. Exit. Enter the amount to be withdrawn : 8000 SUCCESSFULLY DEBITED

1. Create A New Account 2.Deposit Money 3. Check The remaining Balance 4.Withdraw 5. Exit. Your Balance is :1000.0 1. Create A New Account 2.Deposit Money 3. Check The remaining Balance 4.Withdraw 5. Exit. Enter the amount to be withdrawn : 20000 INSUFFIECEINT FUND EXCEPTION TRANSACTION FAILURE 1. Create A New Account 2.Deposit Money 3. Check The remaining Balance 4.Withdraw 5. Exit.

2.

what is Finally Block?

Finally block is used to execute the important code of the program.

Note that It is always executed whether exception is handled or not.

That means eventhough we didnot handle the exception , the code in finally block definitely executed.

By using three cases finally block is explained here.

case 1:- Finally block is executed when the exception does not occur.(finally block is executed here).

import java.io.*;
class finallyBlock{
   public static void main(String[] args) {
       try{
           int a = 30/3; //the case where exception is going to occur.
       }
       catch(NullPointerException e){
           System.out.println(e); // if exception occurs , it will handle using catch
       }
       finally{
           System.out.println("finally block is executed here eventhough exception does not occur");
       }

   }
}

Explanation of case1:-

exception does not occur in the above program because 30 is divided by 3 .So, there is no exception.

Eventhough there is no exception, code in finally block is executed here.

output of case1:-

C:\Users\n150789\Desktop\mlProjects>java finallyBlock finally block is executed here eventhough exception does not occur

case2:- Exception occurs in our program , but not handled that exception.(finally block is executed here).

import java.io.*;
class finallyBlock{
public static void main(String args[]){
try{
int result = 15 / 0; //the case where exception is going to occur.
System.out.println(result);
}
catch(NullPointerException e){
   System.out.println(e); // if exception occurs , it will handle using catch
}
finally{
   System.out.println("finally block is executed eventhough exception is not handled");
}    
}
}

output of case2:-

C:\Users\n150789\Desktop\mlProjects>java finallyBlock finally block is executed eventhough exception is not handled Exception in thread "main" java.lang. ArithmeticException: 7 by zero at finallyBlock.main(finally.java:5)

Explantion of case2:-

If we observe above code 15 is not divided by 0 so arithmetic exception is not present but we handle this exception using null pointer exception that means exception is not handled with the correct exception (arithmetic exception).

Eventhough it does not handled , the code in finally block is executed.

case3:- Exception occurs and handled (finally block is executed here also).

import java.io.*;
class finallyBlock{
public static void main(String args[]){
try{
int result=15/0; //the case where exception is going to occur.
System.out.println(result);
}
catch(ArithmeticException e){
   System.out.println(e); // if exception occurs , it will handle using catch
}
finally{
   System.out.println("finally block is always executed");
}

}
}

output of case 3:-

C:\Users\n150789\Desktop\mlProjects>java finallyBlock java.lang.ArithmeticException: / by zero finally block is always executed

Explantion of case 3: -

If we observe the above code, exception occurs i.e., 15 is not divided by 0 and that is arithmetic exception. In the catch block exception handled. That means there is no problem at all.

Therefore, finally we can say that Finally Block is always executed.

3.

Generate multiple threads of creating clock pulses using Runnable Interface:-

we can create threads using by extending Thread class and by implementing runnable interface.

Note that by creating object using any class does not mean that it is thread.

Thread is created only by using thread class and runnable interface.see below example.

java code :-

import java.io.*;

class multiThread implements Runnable{ //implementing runnable interface to create thread note that runnable interface is implemented by any class.
public void run(){ // this is the only method which will be in runnable interface
  
       for(int i = 1; i < 7;i++){
           try{
               Thread.sleep(500); // sleep method is used to sleep a thread for some amount of time
               System.out.println(i); // printing threads here i created 3 threads.
           }
           catch(InterruptedException e){
               System.out.println(e); // exception handled if it occurs.
           }

       }
}
  
public static void main(String args[]){
multiThread m1 = new multiThread(); //multithread is our created class by using 3 objects are created i.e., m1,m2,and m3
multiThread m2 = new multiThread();
multiThread m3 = new multiThread();

Thread t1 =new Thread(m1); // the object m1 used in thread class to create thread t1.
Thread t2 =new Thread(m2); // the object m2 used in thread class to create thread t2.
Thread t3 =new Thread(m3); // the object m3 used in thread class to create thread t3.
t1.start(); //starting t1 thread
t2.start(); //starting t2 thread
t3.start(); //starting t3 thread
}
}

output:-

C:\Users\n150789\Desktop\mlProjects>java multiThread,

Explantion of output :-

3 threads are created and every thread is stopped for some time i.e., 500 seconds after that time each thread executed.So, first 1,1,1(t1,t2,t3). After 500 seconds 2,2,2(t1,t2,t3) . It will goes on upto the loop termination condition (only 6 times). Because 7th time loop is terminated.