使用Java代码生成文件内容的MD5值

文件内容的MD5值是按照RFC 1864标准，计算出消息体的MD5摘要字符串，即消息体128-bit MD5值经过base64编码后得到的字符串。

生成文件内容的MD5值对应的Java代码示例，如下所示：

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class DacBase64Main {
    public static void main(String[] args) throws NoSuchAlgorithmException, IOException {
        MessageDigest messageDigest = MessageDigest.getInstance("MD5");
        FileInputStream fileInputStream = new FileInputStream("文件地址");
        BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);
        final byte[] buffer = new byte[1024];
        int read;
        while ((read = bufferedInputStream.read(buffer, 0, 1024)) > -1) {
            messageDigest.update(buffer, 0, read);
        }
        byte[] digest = messageDigest.digest();
        String md5 = Base64.getEncoder().encodeToString(digest);
        System.out.println(md5);
    }
}