Java MD5 Byte Array md5(final byte[] data)

Description

Returns the MD5 of the specified bytes

License

Apache License

Parameter

Parameter	Description
data	A byte array

Return

the MD5 sum

Declaration

public static final String md5(final byte[] data) 

Method Source Code

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

import java.io.File;
import java.io.FileInputStream;

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

public class Main {
    /**//  www  . j a  va  2 s . c o  m
     * Returns the MD5 of the specified bytes
     *
     * @param data
     *            A byte array
     * @return the MD5 sum
     */
    public static final String md5(final byte[] data) {
        if (null == data || data.length <= 0) {
            throw new IllegalArgumentException("empty data");
        }

        try {
            final MessageDigest md = MessageDigest.getInstance("MD5");
            return toHexString(md.digest(data));
        } catch (final NoSuchAlgorithmException e) {
            return null;
        }
    }

    /**
     * Returns the MD5 of the specified string
     *
     * @param data
     *            A string value
     * @return the MD5 sum
     */
    public static final String md5(final String data) {
        if (null == data) {
            throw new IllegalArgumentException("null string");
        }

        try {
            final MessageDigest md = MessageDigest.getInstance("MD5");
            return toHexString(md.digest(data.getBytes()));
        } catch (final NoSuchAlgorithmException e) {
            return null;
        }
    }

    /**
     * Returns the MD5 of the specified file
     *
     * @param file
     *            A file
     * @return the MD5 sum of the file
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static String md5(final File file) throws IOException {
        if (null == file || !file.exists()) {
            throw new IllegalArgumentException("file is unavailable");
        }

        final byte[] buf = new byte[1024 * 8];

        try {
            final MessageDigest md = MessageDigest.getInstance("MD5");

            InputStream is = null;

            try {
                is = new FileInputStream(file);

                for (int n = 0; (n = is.read(buf)) != -1;) {
                    md.update(buf, 0, n);
                }
            } finally {
                if (is != null) {
                    try {
                        is.close();
                    } catch (IOException e) {
                    }
                    is = null;
                }
            }

            return new BigInteger(1, md.digest()).toString(16);
        } catch (final NoSuchAlgorithmException e) {
            return null;
        }
    }

    /**
     * Returns the specified data as hex sequence
     *
     * @param data
     *            The data
     * @return a hex string
     */
    public static String toHexString(byte[] data) {
        final int n = data.length;
        final StringBuilder hex = new StringBuilder();

        for (int i = 0; i < n; i++) {
            final byte b = data[i];
            hex.append(String.format("%02x", b & 0xff));
        }

        return hex.toString();
    }
}

Related

1. md5(byte[] source)
2. MD5(byte[] src)
3. md5(byte[] str)
4. md5(final byte[] b)
5. md5(final byte[] bytes)
6. md5Byte(String encryptStr)
7. MD5Bytes(byte[] src)
8. md5Bytes(String message)
9. md5Bytes(String s)