FileUtils.java

/**OpenAtlasForAndroid Project

The MIT License (MIT) 
Copyright (c) 2015 Bunny Blue

Permission is hereby granted, free of charge, to any person obtaining a copy of this software
and associated documentation files (the "Software"), to deal in the Software 
without restriction, including without limitation the rights to use, copy, modify, 
merge, publish, distribute, sublicense, and/or sell copies of the Software, and to 
permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies 
or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
@author BunnyBlue
* **/
package com.openAtlas.bundleInfo.maker;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author BunnyBlue
 *
 */
public class FileUtils {
    /**
     * 获取指定文件 MD5
     *
     * @param pkgFilePath
     * @return
     */
    public static String getMD5(String pkgFilePath) {

        try {
            MessageDigest messageDigest = MessageDigest.getInstance("MD5");
            File mFile = new File(pkgFilePath);
            FileInputStream in = new FileInputStream(mFile);
            FileChannel ch = in.getChannel();
            MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, mFile.length());
            messageDigest.update(byteBuffer);
            byte[] bytes = messageDigest.digest();
            final String HEX = "0123456789abcdef";
            StringBuilder sb = new StringBuilder(bytes.length * 2);
            for (byte b : bytes) {
                // 取出这个字节的高4位，然后与0x0f与运算，得到一个0-15之间的数据，通过HEX.charAt(0-15)即为16进制数
                sb.append(HEX.charAt((b >> 4) & 0x0f));
                // 取出这个字节的低位，与0x0f与运算，得到一个0-15之间的数据，通过HEX.charAt(0-15)即为16进制数
                sb.append(HEX.charAt(b & 0x0f));
            }
            return sb.toString();
        } catch (NoSuchAlgorithmException e) {

            e.printStackTrace();
        } catch (FileNotFoundException e) {

            e.printStackTrace();
        } catch (IOException e) {


        }

        return null;
    }

}