Checked exceptions are the subclass of the Exception class. These types of exceptions occur during the compile time of the program. These exceptions can be handled by the try-catch block otherwise the program will give a compilation error.
ClassNotFoundException, IOException, SQLException etc are the examples of the checked exceptions.
I/O Exception: This Program throw I/O exception because of due FileNotFoundException is a checked exception in Java. Anytime, we want to read a file from the file system, Java forces us to handle error situations where the file is not present in the given location.
Consider myfile.txt file does not exist.
Java
// Java Program to Handle Checked Exception import java.io.*; class GFG { public static void main(String args[]) { FileInputStream GFG = new FileInputStream( "/home/mayur/GFG.txt" ); // this file does not exist in the location /* This constructor FileInputStream * throws FileNotFoundException which * is a checked exception */ } } |
Output:
Handling FileNotFoundException:
This exception can be handled with the help of a try-catch block
- Declare the function using the throw keyword to avoid a Compilation error.
- All the exceptions throw object when they occur try statement allows you to define a block of code to be tested for errors and catch block captures the given exception object and perform required operations.
- Using a try-catch block defined output will be shown.
Java
// Java Program to Handle Checked Exception import java.io.*; import java.util.*; class GFG { public static void main(String[] args) throws FileNotFoundException { FileInputStream GFG = null ; try { GFG = new FileInputStream( "/home/mayur/GFG.txt" ); } catch (FileNotFoundException e) { System.out.println( "File does not exist" ); } } } |
Output:
ClassNotFoundException:
This Exception occurs when methods like Class.forName() and LoadClass Method etc unable to find the given class name as a parameter.
Java
// Java Program to Handle Checked Exception import java.io.*; class GFG { public static void main(String[] args) { Class temp = Class.forName( "gfg" ); // Calling the clas gfg which is not present in the // current class temp instance of calling class it // will throw ClassNotFoundException; } } |
Output:
Handling ClassNotFoundException: Using try-Catch Block
Java
// Java Program to Handle Checked Exception import java.io.*; class GFG { public static void main(String[] args) throws ClassNotFoundException { try { Class temp = Class.forName( "gfg" ); // calling the gfg class } catch (ClassNotFoundException e) { // block executes when mention exception occur System.out.println( "Class does not exist check the name of the class" ); } } } |
Output:
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