Java获取文件的MD5

主要是通过读取文件的字符流，然后赋值给MessageDigest对象，最后将文件流转换成16进制的字符串。

import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.math.BigInteger;import java.security.MessageDigest;import java.security.NoSuchAlGorithmException;public class FileUtils {    private static final int BUFFER_SIZE = 1024;    public static String getFileMd5(File file) {        if (file == null || !file.isFile()) {            return null;        }        MessageDigest digest;        FileInputStream in;        byte[] buffer = new byte[BUFFER_SIZE];        int len;        try {            digest = MessageDigest.getInstance("MD5");            in = new FileInputStream(file);            while ((len = in.read(buffer, 0, BUFFER_SIZE)) != -1) {                digest.update(buffer, 0, len);            }            in.close();        } catch (IOException | NoSuchAlgorithmException e) {            System.out.println(e.getMessage());            return null;        }        BigInteger bigInt = new BigInteger(1, digest.digest());        return bigInt.toString(16);    }}

来源地址：https://blog.csdn.net/qq_41688840/article/details/130517701