Java Digest digest(MessageDigest method, File f)

Description

digest

License

Apache License

Declaration

public static String digest(MessageDigest method, File f)
            throws NoSuchAlgorithmException, FileNotFoundException, IOException 

Method Source Code

//package com.java2s;
/*//from   w w  w .j a  v  a 2 s  .c o m
 * Copyright 2011 Future Systems
 * 
 * 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.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    private static final String[] hexTable = new String[256];

    public static String digest(MessageDigest method, File f)
            throws NoSuchAlgorithmException, FileNotFoundException, IOException {

        byte[] b = new byte[4096];
        FileInputStream fs = new FileInputStream(f);
        while (true) {
            int readBytes = fs.read(b);
            if (readBytes < 0)
                break;

            method.update(b, 0, readBytes);
        }

        byte[] digest = method.digest();
        return toHexString(digest);
    }

    private static String toHexString(byte[] b) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < b.length; i++)
            sb.append(hexTable[b[i] & 0xff]);
        return sb.toString();
    }
}

Related

1. digest(final String algorithm, final byte[] bytes)
2. digest(final String password)
3. digest(InputStream input, String algorithm)
4. digest(InputStream is, String digestAlgorithm)
5. digest(MessageDigest digest, InputStream data)
6. digest(Serializable object)
7. digest(String alg, byte[] plainByte)
8. digest(String algorithm, byte[] bytes)
9. digest(String algorithm, byte[] data)