9. IOExceptions



Answer:
An IOException is thrown.






IOExceptions



    

        

            

            

            

                
                    

                    

                    

                        
                            

                            
import java.io.*;

class WriteTextFile2
{

  public static void main ( String[] args ) 
  {
    String fileName = "reaper.txt" ;

    try
    {  
      // append characters to the file
      FileWriter writer = new FileWriter( fileName, true );

      writer.write( "Alone she cuts and binds the grain,\n"  );  
      writer.write( "And sings a melancholy strain;\n"  );  
      writer.write( "O listen! for the Vale profound\n" );  
      writer.write( "Is overflowing with the sound.\n\n"  );  

      writer.close();
    }
    catch ( IOException iox )
    {
      System.out.println("Problem writing " + fileName );
    }
  }
}

                        		
                    

                
            


        

            

                
Most I/O methods throw an IOException when an error is encountered. A method that uses one of these I/O methods must either (1) include throws IOException in its header, or (2) perform its I/O in a try{} block
                    and then catch IOExceptions. The above program is modified to catch exceptions.

            

            

                
The constructor, the write() method, and the close() method each can throw an IOException. All are caught by the catch block.

                
The program opens the file reaper.txt for appending. Run it and see what it does.

            




            
Question 9:
If you are running a Microsoft operating system, change the permissions of the file reaper.txt to read only. 
(Right-click on the file name in Explorer and then go to properties). Now run the program again. What happens?