Java计算文件MD5值(支持大文件)

 

Java计算文件MD5值(支持大文件)

 package com.hthl.xxtd;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.security.MessageDigest;

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

 /**
  *MD5计算工具 xuxile 2017-09-13
  */
 public class Md5CaculateUtil {

     /**
      * 获取一个文件的md5值(可处理大文件)
      * @return md5 value
      */
     public static String getMD5(File file) {
         FileInputStream fileInputStream = null;
         try {
             MessageDigest MD5 = MessageDigest.getInstance("MD5");
             fileInputStream = new FileInputStream(file);
             byte[] buffer = new byte[8192];
             int length;
             while ((length = fileInputStream.read(buffer)) != -1) {
                 MD5.update(buffer, 0, length);
             }
             return new String(Hex.encodeHex(MD5.digest()));
         } catch (Exception e) {
             e.printStackTrace();
             return null;
         } finally {
             try {
                 if (fileInputStream != null){
                     fileInputStream.close();
                     }
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

     /**
      * 求一个字符串的md5值
      * @param target 字符串
      * @return md5 value
      */
     public static String MD5(String target) {
         return DigestUtils.md5Hex(target);
     }

     public static void main(String[] args) {
         long beginTime = System.currentTimeMillis();
         File file = new File("D:/1/pdi-ce-7.0.0.0-24.zip");
         String md5 = getMD5(file);
         long endTime = System.currentTimeMillis();
         System.out.println("MD5:" + md5 + "\n 耗时:" + ((endTime - beginTime) / 1000) + "s");
     }
 }