Java Hash Calculate getHash(String algorithm, int i)

Description

get Hash

License

Apache License

Declaration

public static String getHash(String algorithm, int i) throws IOException 

Method Source Code

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

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    public static String getHash(String algorithm, int i) throws IOException {
        return getHash(algorithm, String.valueOf(i));
    }//from w w w . j  a v a 2  s. c o  m

    public static String getHash(String algorithm, String string) throws IOException {
        MessageDigest messageDigest = null;

        try {
            messageDigest = MessageDigest.getInstance(algorithm);
        } catch (NoSuchAlgorithmException nsae) {
            throw new IOException(nsae);
        }

        messageDigest.update(string.getBytes("UTF-8"));
        byte[] messageDigestBytes = messageDigest.digest();
        StringBuilder stringBuilder = new StringBuilder();

        for (int i = 0; i < messageDigestBytes.length; i++) {
            stringBuilder.append(Integer.toString((messageDigestBytes[i] & 0xff) + 0x100, 16).substring(1));
        }

        return stringBuilder.toString().toLowerCase();
    }

    private static String getHash(String algorithm, File file) throws IOException {
        MessageDigest messageDigest = null;

        try {
            messageDigest = MessageDigest.getInstance(algorithm);
        } catch (NoSuchAlgorithmException nsae) {
            throw new IOException(nsae);
        }

        InputStream inputStream = null;

        byte[] dataBytes = new byte[1024];
        int bytesRead = 0;
        StringBuilder stringBuilder = new StringBuilder();

        try {
            inputStream = new BufferedInputStream(new FileInputStream(file));

            while ((bytesRead = inputStream.read(dataBytes)) != -1) {
                messageDigest.update(dataBytes, 0, bytesRead);
            }

            byte[] messageDigestBytes = messageDigest.digest();

            for (int i = 0; i < messageDigestBytes.length; i++) {
                stringBuilder.append(Integer.toString((messageDigestBytes[i] & 0xff) + 0x100, 16).substring(1));
            }

            return stringBuilder.toString().toLowerCase();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (Throwable throwable) {
                    // DO NOTHING
                }

                inputStream = null;
            }
        }
    }
}

Related

1. getHash(final byte[] data, final String hashAlgorithm)
2. getHash(final String text, final Charset charset, final MessageDigest algorithm)
3. getHash(InputStream in, String algorithm)
4. getHash(InputStream is, String algorithm)
5. getHash(int iterationNb, String password, byte[] salt)
6. getHash(String credentials)
7. getHash(String Data)
8. getHash(String fileName, String hashType)
9. getHash(String givenStr)