获取文件的Hash值代码实现

来源：互联网发布：windows程序开发工具编辑：程序博客网时间：2024/05/19 18:45
package com.hfq.house.manager.util;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 MD5Util {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;/** * MessageDigest初始化 *  * @author 高焕杰 */static {try {//messagedigest = MessageDigest.getInstance("MD5");messagedigest = MessageDigest.getInstance("SHA-1");} catch (NoSuchAlgorithmException e) {System.err.println("MD5FileUtil messagedigest初始化失败");e.printStackTrace();}}/** * 对文件进行MD5加密 *  * @author 高焕杰 */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());}/** * 对字符串进行MD5加密 *  * @author 高焕杰 */public static String getMD5String(String s) {return getMD5String(s.getBytes());}/** * 对byte类型的数组进行MD5加密 *  * @author 高焕杰 */public static String getMD5String(byte[] bytes) {messagedigest.update(bytes);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++) {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) throws IOException {String filePath = "/Users/jjs/Desktop/13.jpg";long fileBegin = System.currentTimeMillis();System.out.println("文件加密结果为：" + getFileMD5String(new File(filePath)));long fileEnd = System.currentTimeMillis();System.out.println("文件加密耗时:" + ((fileEnd - fileBegin)) + "ms");}}
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