Replace given null values with Apiary nulls and provide doesNotExists…

… option

src/main/java/com/google/gcloud/storage/Blob.java

@@ -16,8 +16,10 @@
 
 package com.google.gcloud.storage;
 
+import static com.google.common.base.MoreObjects.firstNonNull;
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.api.client.util.Data;
 import com.google.api.client.util.DateTime;
 import com.google.api.services.storage.model.ObjectAccessControl;
 import com.google.api.services.storage.model.StorageObject;
@@ -124,22 +126,22 @@ public Builder name(String name) {
     }
 
     public Builder contentType(String contentType) {
-      this.contentType = contentType;
+      this.contentType = firstNonNull(contentType, Data.<String>nullOf(String.class));
       return this;
     }
 
     public Builder contentDisposition(String contentDisposition) {
-      this.contentDisposition = contentDisposition;
+      this.contentDisposition = firstNonNull(contentDisposition, Data.<String>nullOf(String.class));
       return this;
     }
 
     public Builder contentLanguage(String contentLanguage) {
-      this.contentLanguage = contentLanguage;
+      this.contentLanguage = firstNonNull(contentLanguage, Data.<String>nullOf(String.class));
       return this;
     }
 
     public Builder contentEncoding(String contentEncoding) {
-      this.contentEncoding = contentEncoding;
+      this.contentEncoding = firstNonNull(contentEncoding, Data.<String>nullOf(String.class));
       return this;
     }
 
@@ -149,7 +151,7 @@ Builder componentCount(Integer componentCount) {
     }
 
     public Builder cacheControl(String cacheControl) {
-      this.cacheControl = cacheControl;
+      this.cacheControl = firstNonNull(cacheControl, Data.<String>nullOf(String.class));
       return this;
     }
 
@@ -179,12 +181,12 @@ Builder selfLink(String selfLink) {
     }
 
     public Builder md5(String md5) {
-      this.md5 = md5;
+      this.md5 = firstNonNull(md5, Data.<String>nullOf(String.class));
       return this;
     }
 
     public Builder crc32c(String crc32c) {
-      this.crc32c = crc32c;
+      this.crc32c = firstNonNull(crc32c, Data.<String>nullOf(String.class));
       return this;
     }
 
@@ -263,7 +265,7 @@ public String name() {
   }
 
   public String cacheControl() {
-    return cacheControl;
+    return Data.isNull(cacheControl) ? null : cacheControl;
   }
 
   public List<Acl> acl() {
@@ -279,19 +281,19 @@ public Long size() {
   }
 
   public String contentType() {
-    return contentType;
+    return Data.isNull(contentType) ? null : contentType;
   }
 
   public String contentEncoding() {
-    return contentEncoding;
+    return Data.isNull(contentEncoding) ? null : contentEncoding;
   }
 
   public String contentDisposition() {
-    return contentDisposition;
+    return Data.isNull(contentDisposition) ? null : contentDisposition;
   }
 
   public String contentLanguage() {
-    return contentEncoding;
+    return Data.isNull(contentLanguage) ? null : contentLanguage;
   }
 
   public Integer componentCount() {
@@ -307,11 +309,11 @@ public String selfLink() {
   }
 
   public String md5() {
-    return md5;
+    return Data.isNull(md5) ? null : md5;
   }
 
   public String crc32c() {
-    return crc32c;
+    return Data.isNull(crc32c) ? null : crc32c;
   }
 
   public String mediaLink() {
@@ -367,11 +369,11 @@ public Builder toBuilder() {
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
-        .add("bucket", bucket)
-        .add("name", name)
-        .add("size", size)
-        .add("content-type", contentType)
-        .add("metadata", metadata)
+        .add("bucket", bucket())
+        .add("name", name())
+        .add("size", size())
+        .add("content-type", contentType())
+        .add("metadata", metadata())
         .toString();
   }
 
@@ -397,7 +399,7 @@ public boolean equals(Object obj) {
     if (!(obj instanceof Blob)) {
       return  false;
     }
-    return Objects.equals(toPb(), ((Blob)obj).toPb());
+    return Objects.equals(toPb(), ((Blob) obj).toPb());
   }
 
   StorageObject toPb() {

src/main/java/com/google/gcloud/storage/Bucket.java

@@ -17,9 +17,11 @@
 package com.google.gcloud.storage;
 
 import static com.google.api.client.repackaged.com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.MoreObjects.firstNonNull;
 import static com.google.common.collect.Lists.transform;
 
 import com.google.api.client.json.jackson2.JacksonFactory;
+import com.google.api.client.util.Data;
 import com.google.api.client.util.DateTime;
 import com.google.api.services.storage.model.Bucket.Lifecycle;
 import com.google.api.services.storage.model.Bucket.Lifecycle.Rule;
@@ -67,7 +69,6 @@ public final class Bucket implements Serializable {
   private final Location location;
   private final StorageClass storageClass;
 
-
   static final Function<com.google.api.services.storage.model.Bucket, Bucket> FROM_PB_FUNCTION =
       new Function<com.google.api.services.storage.model.Bucket, Bucket>() {
         @Override
@@ -248,6 +249,9 @@ public static final class StorageClass implements Serializable {
 
     private static final long serialVersionUID = 374002156285326563L;
     private static final ImmutableMap<String, Option> STRING_TO_OPTION;
+    private static final StorageClass NULL_VALUE =
+        new StorageClass(Data.<String>nullOf(String.class));
+
     private final String value;
 
     public enum Option {
@@ -299,6 +303,8 @@ public static final class Location implements Serializable {
 
     private static final long serialVersionUID = 9073107666838637662L;
     private static final ImmutableMap<String, Option> STRING_TO_OPTION;
+    private static final Location NULL_VALUE = new Location(Data.<String>nullOf(String.class));
+
     private final String value;
 
     public enum Option {
@@ -392,7 +398,7 @@ Builder selfLink(String selfLink) {
     }
 
     public Builder versioningEnabled(Boolean enable) {
-      this.versioningEnabled = enable;
+      this.versioningEnabled = firstNonNull(enable, Data.<Boolean>nullOf(Boolean.class));
       return this;
     }
 
@@ -412,12 +418,12 @@ public Builder deleteRules(Iterable<DeleteRule> rules) {
     }
 
     public Builder storageClass(StorageClass storageClass) {
-      this.storageClass = storageClass;
+      this.storageClass = firstNonNull(storageClass, StorageClass.NULL_VALUE);
       return this;
     }
 
     public Builder location(Location location) {
-      this.location = location;
+      this.location = firstNonNull(location, Location.NULL_VALUE);
       return this;
     }
 
@@ -493,7 +499,7 @@ public String selfLink() {
   }
 
   public Boolean versioningEnabled() {
-    return versioningEnabled;
+    return Data.isNull(versioningEnabled) ? null : versioningEnabled;
   }
 
   public String indexPage() {
@@ -521,11 +527,11 @@ public Long metageneration() {
   }
 
   public Location location() {
-    return location;
+    return location == null || Data.isNull(location.value) ? null : location;
   }
 
   public StorageClass storageClass() {
-    return storageClass;
+    return storageClass == null || Data.isNull(storageClass.value) ? null : storageClass;
   }
 
   public List<Cors> cors() {
@@ -576,7 +582,7 @@ public boolean equals(Object obj) {
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
-        .add("name", name)
+        .add("name", name())
         .toString();
   }
 

src/main/java/com/google/gcloud/storage/StorageService.java

@@ -121,6 +121,10 @@ public static BlobTargetOption predefinedAcl(PredefinedAcl acl) {
       return new BlobTargetOption(StorageRpc.Option.PREDEFINED_ACL, acl.entry());
     }
 
+    public static BlobTargetOption doesNotExists() {
+      return new BlobTargetOption(StorageRpc.Option.IF_GENERATION_MATCH, 0);
+    }
+
     public static BlobTargetOption generationMatch() {
       return new BlobTargetOption(StorageRpc.Option.IF_GENERATION_MATCH);
     }