Question

Exercise 2:

Try-Catch Exercise

Write a Java code that does the following:

Create a class MyClass and create three methods myMethod1(), Method2() and Method3().

Invoke Method2() from Method1() and Method3() from Method2().

Write a code that can throw an exception inside myMethod3() and compile:

File file=new File("filename.txt");

Scanner sc=new Scanner(file);

You will get compilation errors now, as you are not handling a checked exception FileNotFoundException.

Declare throws over myMethod3() and myMethod2(). You will need to add throws FileNotFoundException on myMethod() as:

public void myMethod3() throws FileNotFoundException

{

File file=new File("filename.txt");

Scanner sc=new Scanner(file);

}

Handle the exception in myMethod1() by enclosing the code that can throw exception using a try-catch block:

public void myMethod1()

{

try{

myMethod2();

}

catch(FileNotFoundException e)

{

e.printStackTrace();

}

}

Answer 1

Program

import java.util.*;
import java.io.*;
public class MyClass {
public void myMethod1(){
   try {
       myMethod2();
   } catch(FileNotFoundException e) {
       e.printStackTrace();
   }
}
public void myMethod2()throws FileNotFoundException {
   myMethod3();
}
public void myMethod3() throws FileNotFoundException {
   File file=new File("filename.txt");
   Scanner sc=new Scanner(file);
}
public static void main(String args[]){
   MyClass m=new MyClass();
   m.myMethod1();
}
}