From 5a4586439d273b9e48c2f2ea0c69bfb1aa27de26 Mon Sep 17 00:00:00 2001
From: andrey-qlogic <andrey@qlogic.io>
Date: Mon, 21 Jan 2019 12:38:51 +0000
Subject: [PATCH] 4117: Added Md5String() method and updated tests.

---
 .../com/google/cloud/storage/BlobInfo.java    | 20 ++++++++++++++++++-
 .../com/google/cloud/storage/BlobTest.java    |  3 +++
 .../storage/snippets/StorageSnippets.java     |  1 +
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/google-cloud-clients/google-cloud-storage/src/main/java/com/google/cloud/storage/BlobInfo.java b/google-cloud-clients/google-cloud-storage/src/main/java/com/google/cloud/storage/BlobInfo.java
index 2ace22d6f9f1..0aca9cd95e60 100644
--- a/google-cloud-clients/google-cloud-storage/src/main/java/com/google/cloud/storage/BlobInfo.java
+++ b/google-cloud-clients/google-cloud-storage/src/main/java/com/google/cloud/storage/BlobInfo.java
@@ -25,13 +25,13 @@
 import com.google.api.services.storage.model.ObjectAccessControl;
 import com.google.api.services.storage.model.StorageObject;
 import com.google.api.services.storage.model.StorageObject.Owner;
-import com.google.cloud.storage.Blob.Builder;
 import com.google.common.base.Function;
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.io.BaseEncoding;
 import java.io.Serializable;
 import java.math.BigInteger;
 import java.util.AbstractMap;
@@ -674,6 +674,24 @@ public String getMd5() {
     return Data.isNull(md5) ? null : md5;
   }
 
+  /**
+   * Returns the MD5 hash of blob's data decoded to string.
+   *
+   * @see <a href="https://cloud.google.com/storage/docs/hashes-etags#_JSONAPI">Hashes and ETags:
+   *     Best Practices</a>
+   */
+  public String getMd5String() {
+    if (md5 == null) {
+      return null;
+    }
+    byte[] decodedMd5 = BaseEncoding.base64().decode(md5);
+    StringBuilder stringBuilder = new StringBuilder();
+    for (byte b : decodedMd5) {
+      stringBuilder.append(String.format("%02x", b & 0xff));
+    }
+    return stringBuilder.toString();
+  }
+
   /**
    * Returns the CRC32C checksum of blob's data as described in <a
    * href="http://tools.ietf.org/html/rfc4960#appendix-B">RFC 4960, Appendix B;</a> encoded in
diff --git a/google-cloud-clients/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java b/google-cloud-clients/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
index ff517d360dd9..c8ce99a1110f 100644
--- a/google-cloud-clients/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
+++ b/google-cloud-clients/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
@@ -76,6 +76,7 @@ public class BlobTest {
   private static final Long GENERATION = 1L;
   private static final String GENERATED_ID = "B/N:1";
   private static final String MD5 = "0xFF00";
+  private static final String MD5_STRING = "d31145d3";
   private static final String MEDIA_LINK = "http://media/b/n";
   private static final Map<String, String> METADATA = ImmutableMap.of("n1", "v1", "n2", "v2");
   private static final Long META_GENERATION = 10L;
@@ -516,6 +517,7 @@ public void testBuilder() {
     assertEquals(ETAG, blob.getEtag());
     assertEquals(GENERATED_ID, blob.getGeneratedId());
     assertEquals(MD5, blob.getMd5());
+    assertEquals(MD5_STRING, blob.getMd5String());
     assertEquals(MEDIA_LINK, blob.getMediaLink());
     assertEquals(METADATA, blob.getMetadata());
     assertEquals(META_GENERATION, blob.getMetageneration());
@@ -547,6 +549,7 @@ public void testBuilder() {
     assertNull(blob.getEtag());
     assertNull(blob.getGeneratedId());
     assertNull(blob.getMd5());
+    assertNull(blob.getMd5String());
     assertNull(blob.getMediaLink());
     assertNull(blob.getMetadata());
     assertNull(blob.getMetageneration());
diff --git a/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java b/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java
index ab2ec4df8edf..7c1f58992ed0 100644
--- a/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java
+++ b/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java
@@ -1141,6 +1141,7 @@ public void getBlobMetadata(String bucketName, String blobName) throws StorageEx
     System.out.println("Id: " + blob.getBlobId());
     System.out.println("KmsKeyName: " + blob.getKmsKeyName());
     System.out.println("Md5Hash: " + blob.getMd5());
+    System.out.println("Md5String: " + blob.getMd5String());
     System.out.println("MediaLink: " + blob.getMediaLink());
     System.out.println("Metageneration: " + blob.getMetageneration());
     System.out.println("Name: " + blob.getName());