data.repository.pragma.utils.MD5Utils.java Source code

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Here is the source code for data.repository.pragma.utils.MD5Utils.java

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/**
 * Copyright [2014-2016] PRAGMA, AIST, Data To Insight Center (IUB)
 *
 * 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.
 */

/*
 * @Author: Quan(Gabriel) Zhou
 */

package data.repository.pragma.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.codec.binary.Hex;

public class MD5Utils {

    public static String getMD5(String file_url) {

        URL url;
        try {
            url = new URL(file_url);
            InputStream is = url.openStream();
            MessageDigest md = MessageDigest.getInstance("MD5");
            String digest = getDigest(is, md, 2048);
            return digest;
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            return null;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            return null;
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            return null;
        }
    }

    public static String getMD5(File file) {

        try {
            FileInputStream is = new FileInputStream(file);
            MessageDigest md = MessageDigest.getInstance("MD5");
            String digest = getDigest(is, md, 2048);
            return digest;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            return null;
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            return null;
        }
    }

    public static String getDigest(InputStream is, MessageDigest md, int byteArraySize) {

        md.reset();
        byte[] bytes = new byte[byteArraySize];
        int numBytes;
        try {
            while ((numBytes = is.read(bytes)) != -1) {
                md.update(bytes, 0, numBytes);
            }
            byte[] digest = md.digest();
            String result = new String(Hex.encodeHex(digest));
            return result;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            return null;
        }
    }
}