文件的md5值工具类

喜欢ヅ旅行 2022-10-22 09:23 153阅读 0赞

package com.hhh.framework.tools.utils;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.security.MessageDigest;
    import java.security.NoSuchAlgorithmException;
    
    public class FileMd5 {
    	protected static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e',
    			'f' };
    
    	/**
    	 * 获取一个文件的md5值(可处理大文件)
    	 * 
    	 * @return md5 value
    	 * @throws NoSuchAlgorithmException
    	 */
    	public static String getMD5(byte[] fileByte) throws NoSuchAlgorithmException {
    		MessageDigest MD5 = MessageDigest.getInstance("MD5");
    		MD5.update(fileByte);
    		return new String(bufferToHex(MD5.digest()));
    	}
    
    	/**
    	 * 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(bufferToHex(MD5.digest()));
    		} catch (Exception e) {
    			e.printStackTrace();
    			return null;
    		} finally {
    			try {
    				if (fileInputStream != null) {
    					fileInputStream.close();
    				}
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    
    
    	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++) {
    			char c0 = hexDigits[(bytes[l] & 0xf0) >> 4];
    			char c1 = hexDigits[bytes[l] & 0xf];
    			stringbuffer.append(c0);
    			stringbuffer.append(c1);
    		}
    		return stringbuffer.toString();
    	}
    
    	public static void main(String[] args) {
    		long beginTime = System.currentTimeMillis();
    		File file = new File("C:\\Users\\AAA\\Documents\\new.bin");
    		String md5 = getMD5(file);
    		long endTime = System.currentTimeMillis();
    		System.out.println("MD5:" + md5 + "\n 耗时:" + ((endTime - beginTime) / 1000) + "s");
    
    	}
    }