package io.bigdata;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.security.MessageDigest;

 import java.security.NoSuchAlgorithmException;

 import java.security.Provider;

 import java.security.Security;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.Set;

 import org.apache.commons.codec.digest.DigestUtils;

 public class Md5CaculateUtil {

     private Md5CaculateUtil(){

     }

     private static char[] hexChar = {

         '0','1','2','3','4','5','6','7','8','9',

         'a','b','c','d','e','f'

     };

     public static String getHash(String fileName,String hashType) throws IOException, NoSuchAlgorithmException{

         File f = new File(fileName);

         System.out.println(" -------------------------------------------------------------------------------");

         System.out.println("|当前文件名称:"+f.getName());

         System.out.println("|当前文件大小:"+(f.length()/1024/1024)+"MB");

         System.out.println("|当前文件路径[绝对]:"+f.getAbsolutePath());

         System.out.println("|当前文件路径[---]:"+f.getCanonicalPath());

         System.out.println(" -------------------------------------------------------------------------------");

         InputStream ins = new FileInputStream(f);

         byte[] buffer = new byte[8192];

         MessageDigest md5 = MessageDigest.getInstance(hashType);

         int len;

         while((len = ins.read(buffer)) != -1){

             md5.update(buffer, 0, len);

         }

         ins.close();

 //        也可以用apache自带的计算MD5方法

         return DigestUtils.md5Hex(md5.digest());

 //        自己写的转计算MD5方法

 //        return toHexString(md5.digest());

     }

     public static String getHash2(String fileName){

         File f = new File(fileName);

         return String.valueOf(f.lastModified());

     }

     protected static String toHexString(byte[] b){

         StringBuilder sb = new StringBuilder(b.length*2);

         for(int i=0;i<b.length;i++){

             sb.append(hexChar[(b[i] & 0xf0) >>> 4]);

             sb.append(hexChar[b[i] & 0x0f]);

         }

         return sb.toString();

     }

     /*

      * 获取MessageDigest支持几种加密算法

      */

     @SuppressWarnings({ "rawtypes", "unchecked" })

     private static String[] getCryptolmpls(String serviceType){

         Set result = new HashSet();

 //        all providers

         Provider[] providers = Security.getProviders();

         for(int i=0;i<providers.length;i++){

 //            get services provided by each provider

             Set keys = providers[i].keySet();

             for(Iterator it = keys.iterator();it.hasNext();){

                 String key = it.next().toString();

                 key = key.split(" ")[0];

                 if(key.startsWith(serviceType+".")){

                     result.add(key.substring(serviceType.length()+1));

                 }else if(key.startsWith("Alg.Alias."+serviceType+".")){

                     result.add(key.substring(serviceType.length()+11));

                 }

             }

         }

         return (String[]) result.toArray(new String[result.size()]);

     }

     public static void main(String[] args) throws Exception, Exception {

 //        调用方法

 //        String[] names = getCryptolmpls("MessageDigest");

 //        for(String name:names){

 //            System.out.println(name);

 //        }

         long start = System.currentTimeMillis();

         System.out.println("开始计算文件MD5值,请稍后...");

         String fileName = "E:\\Office_2010_Toolkit_2.2.3_XiaZaiBa.zip";

 ////        String fileName = "E:\\SoTowerStudio-3.1.0.exe";

         String hashType = "MD5";

         String hash = getHash(fileName,hashType);

         System.out.println("MD5:"+hash);

         long end = System.currentTimeMillis();

         System.out.println("一共耗时:"+(end-start)+"毫秒");

     }

 }