Java Hash Calculate getHash(String fileName, String hashType)

Description

get Hash

License

Apache License

Declaration

private static String getHash(String fileName, String hashType) throws Exception 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.io.FileInputStream;
import java.io.InputStream;

import java.security.MessageDigest;

public class Main {
    private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c",
            "d", "e", "f" };

    private static String getHash(String fileName, String hashType) throws Exception {
        InputStream fis;/*from www .  j  a v a2s  .  c  o  m*/
        fis = new FileInputStream(fileName);
        byte[] buffer = new byte[1024];
        MessageDigest md5 = MessageDigest.getInstance(hashType);
        int numRead = 0;
        while ((numRead = fis.read(buffer)) > 0) {
            md5.update(buffer, 0, numRead);
        }
        fis.close();
        // return toHexString(md5.digest());
        return byteArrayToHexString(md5.digest());
    }

    private static String byteArrayToHexString(byte[] b) {
        StringBuffer resultSb = new StringBuffer();

        for (int i = 0; i < b.length; i++) {
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n = 256 + n;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }
}

Related

1. getHash(InputStream is, String algorithm)
2. getHash(int iterationNb, String password, byte[] salt)
3. getHash(String algorithm, int i)
4. getHash(String credentials)
5. getHash(String Data)
6. getHash(String givenStr)
7. getHash(String input)
8. getHash(String input)
9. getHash(String key)