+package net.jpountz.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * @author Tuukka Lehtonen
+ */
+public final class ChecksumUtil {
+
+ private static byte[] computeSum(InputStream in) throws IOException {
+ if (in == null)
+ throw new IllegalArgumentException("Input cannot be null!");
+
+ MessageDigest md;
+ try {
+ md = MessageDigest.getInstance("MD5");
+ } catch (NoSuchAlgorithmException e) {
+ throw new Error("MD5 digest must be supported by JVM");
+ }
+ byte[] data = new byte[64 * 1024];
+
+ while (true) {
+ int read = in.read(data);
+ if (read == -1) {
+ return md.digest();
+ }
+ md.update(data, 0, read);
+ }
+ }
+
+ public static byte[] computeSum(Path p) throws IOException {
+ try (InputStream in = Files.newInputStream(p)) {
+ return computeSum(in);
+ }
+ }
+
+ public static byte[] computeSum(URL url) throws IOException {
+ try (InputStream in = url.openStream()) {
+ return computeSum(in);
+ }
+ }
+
+}