Java计算文件MD5值代码，java计算md5代码,import java.

Java计算文件MD5值代码，java计算md5代码,import java.

import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.nio.MappedByteBuffer;import java.nio.channels.FileChannel;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;public class FileMd5Utils {     protected static char hexDigits[] = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};          protected static MessageDigest messageDigest = null;          static{            try{                  messageDigest = MessageDigest.getInstance("MD5");              }catch (NoSuchAlgorithmException e) {                  System.err.println(FileMd5Utils.class.getName()+"初始化失败，MessageDigest不支持MD5Util.");                  e.printStackTrace();              }          }          /**          * 计算文件的MD5          * @param fileName 文件的绝对路径          * @return          * @throws IOException          */          public static String getFileMD5String(String fileName) throws IOException{              File f = new File(fileName);              return getFileMD5String(f);          }          /**          * 计算文件的MD5，重载方法          * @param file 文件对象          * @return          * @throws IOException          */          public static String getFileMD5String(File file) throws IOException{              FileInputStream in = new FileInputStream(file);              FileChannel ch = in.getChannel();              MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());              messageDigest.update(byteBuffer);              return bufferToHex(messageDigest.digest());          }          private static String bufferToHex(byte bytes[]) {             return bufferToHex(bytes, 0, bytes.length);          }          private static String bufferToHex(byte bytes[], int m, int n) {             StringBuffer stringbuffer = new StringBuffer(2 * n);             int k = m + n;             for (int l = m; l < k; l++) {              appendHexPair(bytes[l], stringbuffer);             }             return stringbuffer.toString();          }          private static void appendHexPair(byte bt, StringBuffer stringbuffer) {             char c0 = hexDigits[(bt &amp; 0xf0) >> 4];             char c1 = hexDigits[bt &amp; 0xf];             stringbuffer.append(c0);             stringbuffer.append(c1);          }          public static void main(String[] args) throws IOException {              String fileName = "F:\\test01\\1.txt";            String str = "d0970714757783e6cf17b26fb8e2298f";            String str2 = "ea3ed20b6b101a09085ef09c97da1597";            System.out.println(str.equals(str2));            System.out.println(getFileMD5String(fileName));        }  }