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Example : A simple Java program without Exception Handling.
import java.io.*;
import java.util.Scanner;
class Exception
{
public static void main(String[] args)
{
int x, y, output;
Scanner sc = new Scanner(System.in);
System.out.println("Enter two integer number");
x = sc.nextInt();
y = sc.nextInt();
output = x / y;
System.out.println("Result= " + output);
}
}
Save as je.java on desktop
Output1 :
C:\Users\Raj>cd desktop
C:\Users\Raj\Desktop>javac je.java
C:\Users\Raj\Desktop>java Exception
Enter two integer number
21
3
Result= 7
Output2 :
C:\Users\Raj\Desktop>javac je.java
C:\Users\Raj\Desktop>java Exception
Enter two integer number
20
0
Exception in thread "main" java.lang.ArithmeticException: / by zero
at Exception.main(je.java:17)Example : A Java program to display Exception Handling using Try, Catch, and Finally Statement.
import java.io.*;
import java.util.Scanner;
class Test
{
public static void main(String[] args)
{
int x, y, output;
Scanner input = new Scanner(System.in);
System.out.println("Enter two integer number");
x = input.nextInt();
y = input.nextInt();
// try block
try
{
output = x / y;
System.out.println("Result = " + output);
}
// catch block
catch (ArithmeticException e) //Specific Exception
{
//System.out.println("Exception arise & caught is : Division by zero.");
System.out.println("Exception arise is = " +e.getMessage());
}
finally
{
System.out.println("Program finally Terminated");
}
}
}
Output:
D:\>java Test
Enter two integer number
20
5
Result = 4
Program finally TerminatedExample : A simple Java program demonstration with Specific Exception Handling.
import java.io.*;
import java.util.Scanner;
class Test
{
public static void main(String[] args)
{
int x, y, output;
Scanner input = new Scanner(System.in);
System.out.println("Enter two integer number");
x = input.nextInt();
y = input.nextInt();
// try block
try
{
output = x / y;
System.out.println("Result = " + output);
}
// catch block
catch (ArithmeticException e) //Specific Exception
{
//System.out.println("Exception arise & caught is : Division by zero.");
System.out.println("Exception arise is = " +e.getMessage());
}
}
}
Output1 :
C:\Users\Raj\Desktop>javac je1.java
C:\Users\Raj\Desktop>java Exception
Enter two integer number
25
5
Result = 5
Output2 :
C:\Users\Raj\Desktop>javac je1.java
C:\Users\Raj\Desktop>java Exception
Enter two integer number
20
0
Exception arise is = Division / by zeroExample : A simple Java program without/with Specific Exception Handling.
(Without Exception Handling)
class Example
{
public static void main(String[] args)
{
int arr[] = {41,85,72,10,50};
System.out.println("Value Stored at : " + arr[4]);
System.out.println("Value Stored at : " + arr[2]);
System.out.println("Value Stored at : " + arr[7]);
}
}
F:\>javac abc1.java
F:\>java Example
Value Stored at : 50
Value Stored at : 72
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 7
at Test.main(Program.java:8)
-------- OR --------
(With Specific Exception Handling)
class Example
{
public static void main(String[] args)
{
try
{
int arr[] = {41,85,72,10,50};
System.out.println("Value Stored at : " + arr[4]);
System.out.println("Value Stored at : " + arr[7]);
System.out.println("Value Stored at : " + arr[2]);
}
catch( ArrayIndexOutOfBoundsException e)
{
System.out.println("Value is not present because it is beyond the
size of array");
}
}
}
Output :
F:\>javac abc1.java
F:\>java Example
Value Stored at : 50
Value is not present because it is beyond the size of arrayExample : A Java program to demonstrate Multiple Catch Statements using Exception Handling.
class Sample
{
public static void main(String[] args)
{
try
{
int x[]=new int[10];
x[12]=45/0;
}
catch(ArithmeticException e)
{
System.out.println("Division by Zero Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Array Index Out Of Bounds Exception occurs");
}
catch(Exception e)
{
System.out.println("An Exception occurs");
}
}
}
Output:
D:\>javac Program.java
D:\>java Sample
Division by Zero Exception occurs
--------------------- OR ----------------------
class Sample
{
public static void main(String[] args)
{
try
{
int x[]=new int[10];
System.out.println(x[13]);
}
catch(ArithmeticException e)
{
System.out.println("Division by Zero Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Array Index Out Of Bounds Exception occurs");
}
catch(Exception e)
{
System.out.println("An Exception occurs");
}
}
}
Output:
D:\>javac Program.java
D:\>java Sample
Array Index Out Of Bounds Exception occurs
------------------- OR -------------------
class Sample
{
public static void main(String[] args)
{
try
{
String str=null;
System.out.println(str.length());
}
catch(NullPointerException e)
{
System.out.println("Null Pointer Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Array Index Out Of Bounds Exception occurs");
}
catch(Exception e)
{
System.out.println("An Exception occurs");
}
}
}
Output:
D:\>javac Program.java
D:\>java Sample
Null Pointer Exception occurs
----------------- OR -----------------
class Sample
{
public static void main(String[] args)
{
try
{
String str="India";
int i=Integer.parseInt(str);//NumberFormatException
}
catch(NullPointerException e)
{
System.out.println("Null Pointer Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Array Index Out Of Bounds Exception occurs");
}
catch(NumberFormatException e)
{
System.out.println("Number Format Exception occurs");
}
}
}
Output:
D:\>javac Program.java
D:\>java Sample
Number Format Exception occursExample : A Java program to demonstrate Nested Try Statements using Exception Handling.
class First
{
public static void main(String args[])
{
//outer try block
try
{
//String str=null;
//System.out.println(str.length());
//inner try block 1
try
{
int x = 12/0;
}
//catch block of inner try block 1
catch(ArithmeticException e)
{
System.out.println(e);
}
//inner try block 2
try
{
int arr[]=new int[5];
//assigning the value out of array bounds
arr[6]=40;
}
//catch block of inner try block 2
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println(e);
}
}
//catch block of outer try block
catch(NullPointerException e)
{
System.out.println("Outer Catch Null Pointer Exception Arise");
}
}
}
Output:
D:\>javac Program.java
D:\>java First
java.lang.ArithmeticException: / by zero
java.lang.ArrayIndexOutOfBoundsException: 6
------------------ OR -------------------
class First
{
public static void main(String args[])
{
//outer try block
try
{
String str=null;
System.out.println(str.length());
//inner try block 1
try
{
System.out.println("Division by 0 Exception");
int x = 12/0;
}
//catch block of inner try block 1
catch(ArithmeticException e)
{
System.out.println(e);
}
//inner try block 2
try
{
int arr[]=new int[5];
//assigning the value out of array bounds
arr[6]=40;
}
//catch block of inner try block 2
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println(e);
}
}
//catch block of outer try block
catch(NullPointerException e)
{
System.out.println("Outer Catch Null Pointer Exception Arise");
}
}
}
Output:
D:\>javac Program.java
D:\>java First
Outer Catch Null Pointer Exception AriseExample : A simple Java program to demonstrate Throw Keyword using Exception Handling.
class Example
{
public static void divideByZero()
{
// throw a customized exception
throw new ArithmeticException("Trying to divide by 0");
}
public static void main(String[] args)
{
divideByZero();
}
}
Output:
D:\>javac Program.java
D:\>java Test
Exception in thread "main" java.lang.ArithmeticException: Trying to divide by 0
at Test.divideByZero(Program.java:7)
at Test.main(Program.java:12)Example : A Java program to demonstrate Throws Keyword using Exception Handling.
import java.io.*;
class Example
{
// declareing the type of exception
public static void findFile() throws IOException
{
// code that may generate IOException
File newFile = new File("test.txt");
FileInputStream stream = new FileInputStream(newFile);
}
public static void main(String[] args)
{
try
{
findFile();
}
catch (IOException e)
{
System.out.println(e);
}
}
}
Output:
D:\>javac Program.java
D:\>java Example
java.io.FileNotFoundException: test.txt (The system cannot find the file specified)
NB:
When we run this program, if the file test.txt does not exist, FileInputStream throws a FileNotFoundException which extends the IOException class.Example : A Java program to demonstrate the Multiple Throws Concept using Exception Handling.
import java.io.*;
class Example
{
public static void findFile() throws NullPointerException, IOException, InvalidClassException
{
// codes that may produce NullPointerException
---
---
// codes that may produce IOException
---
---
// codes that may produce InvalidClassException
---
---
}
public static void main(String[] args)
{
try
{
findFile();
}
catch(IOException e1)
{
System.out.println(e1.getMessage());
}
catch(InvalidClassException e2)
{
System.out.println(e2.getMessage());
}
catch(NullPointerException e3)
{
System.out.println(e3.getMessage());
}
}
}Example : A Java program to demonstrate Throw Keyword using Throws Exception Handling.
import java.io.*;
class Example
{
public static void findFile() throws IOException
{
throw new IOException("File does not exists");
}
public static void main(String[] args)
{
try
{
findFile();
}
catch (IOException e)
{
System.out.println(e.getMessage());
}
}
}
Output:
D:\>javac Program.java
D:\>java Example
File does not exists 
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