feat: add preview MultipartUploadClient#completeMultipartUpload

google-cloud-storage/src/main/java/com/google/cloud/storage/MultipartUploadClient.java

@@ -20,6 +20,8 @@
 import com.google.api.core.InternalExtensionOnly;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadResponse;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadRequest;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.ListPartsRequest;
@@ -73,6 +75,17 @@ public abstract CreateMultipartUploadResponse createMultipartUpload(
   public abstract AbortMultipartUploadResponse abortMultipartUpload(
       AbortMultipartUploadRequest request);
 
+  /**
+   * Completes a multipart upload.
+   *
+   * @param request The request object containing the details for completing the multipart upload.
+   * @return A {@link CompleteMultipartUploadResponse} object containing information about the
+   *     completed upload.
+   */
+  @BetaApi
+  public abstract CompleteMultipartUploadResponse completeMultipartUpload(
+      CompleteMultipartUploadRequest request);
+
   /**
    * Uploads a part in a multipart upload.
    *

google-cloud-storage/src/main/java/com/google/cloud/storage/MultipartUploadClientImpl.java

@@ -20,6 +20,8 @@
 import com.google.cloud.storage.Retrying.Retrier;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadResponse;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadRequest;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.ListPartsRequest;
@@ -79,6 +81,16 @@ public AbortMultipartUploadResponse abortMultipartUpload(AbortMultipartUploadReq
         Decoder.identity());
   }
 
+  @Override
+  @BetaApi
+  public CompleteMultipartUploadResponse completeMultipartUpload(
+      CompleteMultipartUploadRequest request) {
+    return retrier.run(
+        retryAlgorithmManager.idempotent(),
+        () -> httpRequestManager.sendCompleteMultipartUploadRequest(uri, request),
+        Decoder.identity());
+  }
+
   @Override
   @BetaApi
   public UploadPartResponse uploadPart(UploadPartRequest request, RequestBody requestBody) {

google-cloud-storage/src/main/java/com/google/cloud/storage/MultipartUploadHttpRequestManager.java

@@ -31,6 +31,8 @@
 import com.google.cloud.storage.Crc32cValue.Crc32cLengthKnown;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.AbortMultipartUploadResponse;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadRequest;
+import com.google.cloud.storage.multipartupload.model.CompleteMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadRequest;
 import com.google.cloud.storage.multipartupload.model.CreateMultipartUploadResponse;
 import com.google.cloud.storage.multipartupload.model.ListPartsRequest;
@@ -44,6 +46,7 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URLEncoder;
+import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.regex.Matcher;
@@ -111,11 +114,33 @@ AbortMultipartUploadResponse sendAbortMultipartUploadRequest(
     String abortUri = uri.toString() + resourcePath + queryString;
 
     HttpRequest httpRequest = requestFactory.buildDeleteRequest(new GenericUrl(abortUri));
+    httpRequest.getHeaders().putAll(headerProvider.getHeaders());
     httpRequest.setParser(objectParser);
     httpRequest.setThrowExceptionOnExecuteError(true);
     return httpRequest.execute().parseAs(AbortMultipartUploadResponse.class);
   }
 
+  CompleteMultipartUploadResponse sendCompleteMultipartUploadRequest(
+      URI uri, CompleteMultipartUploadRequest request) throws IOException {
+    String encodedBucket = urlEncode(request.bucket());
+    String encodedKey = urlEncode(request.key());
+    String resourcePath = "/" + encodedBucket + "/" + encodedKey;
+    String queryString = "?uploadId=" + request.uploadId();
+    String completeUri = uri.toString() + resourcePath + queryString;
+    byte[] bytes = new XmlMapper().writeValueAsBytes(request.multipartUpload());
+    HttpRequest httpRequest =
+        requestFactory.buildPostRequest(
+            new GenericUrl(completeUri), new ByteArrayContent("application/xml", bytes));
+    httpRequest.getHeaders().putAll(headerProvider.getHeaders());
+    @Nullable Crc32cLengthKnown crc32cValue = Hasher.defaultHasher().hash(ByteBuffer.wrap(bytes));
+    if (crc32cValue != null) {
+      addChecksumHeader(crc32cValue, httpRequest.getHeaders());
+    }
+    httpRequest.setParser(objectParser);
+    httpRequest.setThrowExceptionOnExecuteError(true);
+    return httpRequest.execute().parseAs(CompleteMultipartUploadResponse.class);
+  }
+
   UploadPartResponse sendUploadPartRequest(
       URI uri, UploadPartRequest request, RewindableContent rewindableContent) throws IOException {
     String encodedBucket = urlEncode(request.bucket());

google-cloud-storage/src/main/java/com/google/cloud/storage/multipartupload/model/CompleteMultipartUploadRequest.java

@@ -0,0 +1,174 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage.multipartupload.model;
+
+import com.google.common.base.MoreObjects;
+import java.util.Objects;
+
+/** Represents a request to complete a multipart upload. */
+public final class CompleteMultipartUploadRequest {
+
+  private final String bucket;
+  private final String key;
+  private final String uploadId;
+  private final CompletedMultipartUpload multipartUpload;
+
+  private CompleteMultipartUploadRequest(Builder builder) {
+    this.bucket = builder.bucket;
+    this.key = builder.key;
+    this.uploadId = builder.uploadId;
+    this.multipartUpload = builder.multipartUpload;
+  }
+
+  /**
+   * Returns the bucket name.
+   *
+   * @return The bucket name.
+   */
+  public String bucket() {
+    return bucket;
+  }
+
+  /**
+   * Returns the object name.
+   *
+   * @return The object name.
+   */
+  public String key() {
+    return key;
+  }
+
+  /**
+   * Returns the upload ID of the multipart upload.
+   *
+   * @return The upload ID.
+   */
+  public String uploadId() {
+    return uploadId;
+  }
+
+  /**
+   * Returns the {@link CompletedMultipartUpload} payload for this request.
+   *
+   * @return The {@link CompletedMultipartUpload} payload.
+   */
+  public CompletedMultipartUpload multipartUpload() {
+    return multipartUpload;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof CompleteMultipartUploadRequest)) {
+      return false;
+    }
+    CompleteMultipartUploadRequest that = (CompleteMultipartUploadRequest) o;
+    return Objects.equals(bucket, that.bucket)
+        && Objects.equals(key, that.key)
+        && Objects.equals(uploadId, that.uploadId)
+        && Objects.equals(multipartUpload, that.multipartUpload);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(bucket, key, uploadId, multipartUpload);
+  }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+        .add("bucket", bucket)
+        .add("key", key)
+        .add("uploadId", uploadId)
+        .add("completedMultipartUpload", multipartUpload)
+        .toString();
+  }
+
+  /**
+   * Creates a new builder for {@link CompleteMultipartUploadRequest}.
+   *
+   * @return A new builder.
+   */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  /** Builder for {@link CompleteMultipartUploadRequest}. */
+  public static class Builder {
+    private String bucket;
+    private String key;
+    private String uploadId;
+    private CompletedMultipartUpload multipartUpload;
+
+    private Builder() {}
+
+    /**
+     * Sets the bucket name.
+     *
+     * @param bucket The bucket name.
+     * @return This builder.
+     */
+    public Builder bucket(String bucket) {
+      this.bucket = bucket;
+      return this;
+    }
+
+    /**
+     * Sets the object name.
+     *
+     * @param key The object name.
+     * @return This builder.
+     */
+    public Builder key(String key) {
+      this.key = key;
+      return this;
+    }
+
+    /**
+     * Sets the upload ID of the multipart upload.
+     *
+     * @param uploadId The upload ID.
+     * @return This builder.
+     */
+    public Builder uploadId(String uploadId) {
+      this.uploadId = uploadId;
+      return this;
+    }
+
+    /**
+     * Sets the {@link CompletedMultipartUpload} payload for this request.
+     *
+     * @param completedMultipartUpload The {@link CompletedMultipartUpload} payload.
+     * @return This builder.
+     */
+    public Builder multipartUpload(CompletedMultipartUpload completedMultipartUpload) {
+      this.multipartUpload = completedMultipartUpload;
+      return this;
+    }
+
+    /**
+     * Builds the {@link CompleteMultipartUploadRequest} object.
+     *
+     * @return The new {@link CompleteMultipartUploadRequest} object.
+     */
+    public CompleteMultipartUploadRequest build() {
+      return new CompleteMultipartUploadRequest(this);
+    }
+  }
+}