Java Checksum Calculate generateChecksum(String pType, String pInFile)

Description

Generates a checksum for a file

License

Apache License

Parameter

Parameter	Description
pType	type of checksum to generate (MD5/SHA1 etc)
pInFile	file to checksum

Exception

Parameter	Description
IOException	file access error

Return

A String with the format MD5:XXXXXX or SHA1:XXXXXX

Declaration

public static String generateChecksum(String pType, String pInFile) throws IOException 

Method Source Code

//package com.java2s;
/*//from   w w w .ja  v a  2 s  .c  om
 * Copyright 2014 The British Library/SCAPE Project Consortium
 * Author: William Palmer (William.Palmer@bl.uk)
 *
 *   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 final static int BUFSIZE = 32768;

    /**
     * Generates a checksum for a file 
     * @param pType type of checksum to generate (MD5/SHA1 etc)
     * @param pInFile file to checksum
     * @return A String with the format MD5:XXXXXX or SHA1:XXXXXX
     * @throws IOException file access error
     */
    public static String generateChecksum(String pType, String pInFile) throws IOException {

        if (!new File(pInFile).exists())
            throw new IOException("File not found: " + pInFile);

        MessageDigest md;
        try {
            md = MessageDigest.getInstance(pType.toUpperCase());
        } catch (NoSuchAlgorithmException e) {
            return null;
        }

        FileInputStream input;
        try {
            input = new FileInputStream(pInFile);
            byte[] readBuffer = new byte[BUFSIZE];
            int bytesRead = 0;
            while (input.available() > 0) {
                bytesRead = input.read(readBuffer);
                md.update(readBuffer, 0, bytesRead);
            }
            input.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        String hash = "";
        for (byte b : md.digest())
            hash += String.format("%02x", b);
        return hash;
    }

    /**
     * Generates a checksum for a file 
     * @param pInFile file to checksum
     * @return A String with the format MD5:XXXXXX or SHA1:XXXXXX
     * @throws IOException file access error
     */
    public static String generateChecksum(String pInFile) throws IOException {

        String type = "MD5";
        return type + ":" + generateChecksum(type, pInFile);

    }
}

Related

1. checksumFile(File file)
2. checksumLength(int algorithmCode, int dataLength)
3. createChecksum(File file, String shaAlgo)
4. generateChecksum(InputStream is)
5. generateChecksum(String path, String flavor)
6. generateCheckSum(String string)
7. getChecksum(byte[] buffer, int offset, int length)
8. getChecksum(final File file)
9. getCheckSum(String filePath)