Java SHA1 sha1DigestAsHex(String data)

Description

Returns the SHA1 of the provided data

License

Apache License

Parameter

Parameter	Description
data	The data to calculate, such as the contents of a file

Return

The human-readable SHA1

Declaration

public static String sha1DigestAsHex(String data) 

Method Source Code

//package com.java2s;
/*/*www .ja v a  2 s.  c  o m*/
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    private static final char[] HEX_CHARS = { '0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
    private static final Charset UTF8_CHARSET = Charset.forName("UTF8");

    /**
     * Returns the SHA1 of the provided data
     * 
     * @param data The data to calculate, such as the contents of a file
     * @return The human-readable SHA1
     */
    public static String sha1DigestAsHex(String data) {
        byte[] dataBytes = getDigest("SHA").digest(
                data.getBytes(UTF8_CHARSET));
        return new String(encodeHex(dataBytes));
    }

    /**
     * Creates a new {@link MessageDigest} with the given algorithm. Necessary because {@code MessageDigest} is not
     * thread-safe.
     */
    private static MessageDigest getDigest(String algorithm) {
        try {
            return MessageDigest.getInstance(algorithm);
        } catch (NoSuchAlgorithmException ex) {
            throw new IllegalStateException(
                    "Could not find MessageDigest with algorithm \""
                            + algorithm + "\"", ex);
        }
    }

    private static char[] encodeHex(byte[] data) {
        int l = data.length;
        char[] out = new char[l << 1];
        for (int i = 0, j = 0; i < l; i++) {
            out[j++] = HEX_CHARS[(0xF0 & data[i]) >>> 4];
            out[j++] = HEX_CHARS[0x0F & data[i]];
        }
        return out;
    }
}

Related

1. SHA1Checksum(String filename)
2. sha1Digest(byte[] bytes)
3. sha1Digest(byte[] bytes)
4. sha1Digest(final InputStream data)
5. sha1Digest(String src)
6. sha1Encode(byte[] content)
7. SHA1Encode(String sourceString)
8. sha1Hash()
9. sha1hash(byte[] blob)