Java MD5 加密简例

package com.sub.md5;

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

public class TestMd5 {
	
	
	public static void main(String[] args) throws NoSuchAlgorithmException, IOException{
		MessageDigest digest = MessageDigest.getInstance("MD5");
		File file = new File("f:/md5/left.xlsx");
		InputStream is = new FileInputStream(file);
		int length = -1;
		byte[] buffer = new byte[2048];
        while ((length = is.read(buffer)) != -1) {
        	digest.update(buffer, 0, length);
        }
		String s = byto2hex2(digest.digest());
		System.out.println(s);
	}

	
	private static String byto2hex2(byte[] bin){
	    StringBuffer buf = new StringBuffer();
	    for (int i = 0; i < bin.length; ++i) {
	        int x = bin[i] & 0xFF, h = x >>> 4, l = x & 0x0F;
	        buf.append((char) (h + ((h < 10) ? '0' : 'a' - 10)));
	        buf.append((char) (l + ((l < 10) ? '0' : 'a' - 10)));
	    }
	    return buf.toString();
	}
}