BAEL-5615-gen-md5-checksum-of-file (#12668)

Co-authored-by: tienvn4 <tienvn4@ghtk.co>

core-java-modules/core-java-io-4/src/main/java/com/baeldung/md5checksum/Md5ChecksumGenerator.java

@@ -0,0 +1,44 @@
+package com.baeldung.md5checksum;
+
+import com.google.common.hash.HashCode;
+import com.google.common.hash.Hashing;
+import com.google.common.io.ByteSource;
+import org.apache.commons.codec.digest.DigestUtils;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigInteger;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public class Md5ChecksumGenerator {
+
+    public static String genWithApacheCommons(String filePath) throws IOException {
+        try (InputStream is = Files.newInputStream(Paths.get(filePath))) {
+            return DigestUtils.md5Hex(is);
+        }
+    }
+
+    public static String genWithGuava(String filePath) throws IOException {
+        File file = new File(filePath);
+        ByteSource byteSource = com.google.common.io.Files.asByteSource(file);
+        HashCode hc = byteSource.hash(Hashing.md5());
+        return hc.toString();
+    }
+
+    public static String genWithMessageDigest(String filePath) throws IOException, NoSuchAlgorithmException {
+        byte[] data = Files.readAllBytes(Paths.get(filePath));
+        byte[] hash = MessageDigest.getInstance("MD5").digest(data);
+        return new BigInteger(1, hash).toString(16);
+    }
+
+    public static void main(String[] args) throws IOException, NoSuchAlgorithmException {
+        String filePath = "D:\\temp.txt";
+        System.out.println(genWithApacheCommons(filePath));
+        System.out.println(genWithMessageDigest(filePath));
+        System.out.println(genWithGuava(filePath));
+    }
+}