public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		HashFile hashFile = new HashFile("Originale.txt","SHA");
		HashFile hashFile1 = new HashFile("Originale.txt","MD5");
		
		System.out.println(hashFile.equals(hashFile1)); //False 

                // Risposta della funzione equals() 
                // false
                // SHA: 44d3a83db52a0cf0f908ad0ef55c83f4771f66ad
                // MD5: ed0a96e83ab7b0910fcbcc131b2e6b82

		System.out.println("SHA: " + hashFile.HashFileGenera());
		System.out.println("MD5: " + hashFile1.HashFileGenera());
		
		System.out.println(hashFile.toString());

	}

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


public class HashFile {

	private File file;
	private String Algoritmo;
	
	public HashFile(String filename,String Algoritmo){
		this.file = new File(filename);
		this.Algoritmo = Algoritmo;
	}
	
	public String HashFileGenera() {
		String output;
	try{
		MessageDigest digest = MessageDigest.getInstance(this.Algoritmo);
		InputStream is = new FileInputStream(file);                
		byte[] buffer = new byte[8192];
		int read = 0;
		try {
		    while( (read = is.read(buffer)) > 0) {
		        digest.update(buffer, 0, read);
		    }       
		    byte[] md5sum = digest.digest();
		    BigInteger bigInt = new BigInteger(1, md5sum);
		    output = bigInt.toString(16);
//		   System.out.println("MD5: " + output);
		    return output;
		}
		catch(IOException e) {
		    throw new RuntimeException("Unable to process file for "+this.Algoritmo, e);
		}
		finally {
		    try {
		        is.close();
		    }
		    catch(IOException e) {
		        throw new RuntimeException("Unable to close input stream for "+this.Algoritmo+" calculation", e);
		    }
		}       
	 }catch(NoSuchAlgorithmException | FileNotFoundException e){
	      e.printStackTrace();
	     }
	return Algoritmo;
	}
	
	
	public String toString(){
		return (
				"" + this.Algoritmo + " : " + this.HashFileGenera()
				);
	}

	public boolean equals(Object o){
		HashFile p = (HashFile) o;
		
		return ( this.HashFileGenera().equals(p.HashFileGenera())
				);
		
	}

}