Add all the necessary exception declarations to remove the

Question

Add all the necessary exception declarations to remove the compile-time errors

import java.io.*; 
 
public class L9 { 
 
    public static String cat( String fileName ) { 
 
        FileInputStream fin = new FileInputStream( fileName ); 
 
        BufferedReader input = new BufferedReader( new InputStreamReader( fin ) ); 
 
        StringBuffer buffer = new StringBuffer(); 
 
        String line = null; 
 
        while ( ( line = input.readLine() ) != null ) { 
 
  line = line.replaceAll( "\s+", " " ); 
 
  buffer.append( line ); 
 
        } 
 
        fin.close(); 
 
        return buffer.toString(); 
 
    } // End of cat 
 
    public static void main( String[] args ) { 
 
        System.out.println( cat( args[ 0 ] ) ); 
 
    } 
}