Google Storage blob copy writer. A CopyWriter object allows to copy both blob's data and
information. To override source blob's information supply a BlobInfo to the
CopyRequest using either Storage.CopyRequest.Builder#setTarget(BlobInfo,
Storage.BlobTargetOption...) or Storage.CopyRequest.Builder#setTarget(BlobInfo,
Iterable).
This class holds the result of a copy request. If source and destination blobs share the same
location and storage class the copy is completed in one RPC call otherwise one or more #copyChunk calls are necessary to complete the copy. In addition, CopyWriter#getResult()
can be used to automatically complete the copy and return information on the newly created blob.
See Also: Rewrite
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-28 UTC."],[],[],null,["# Class CopyWriter (2.55.0)\n\nVersion latestkeyboard_arrow_down\n\n- [2.55.0 (latest)](/java/docs/reference/google-cloud-storage/latest/com.google.cloud.storage.CopyWriter)\n- [2.54.0](/java/docs/reference/google-cloud-storage/2.54.0/com.google.cloud.storage.CopyWriter)\n- [2.53.3](/java/docs/reference/google-cloud-storage/2.53.3/com.google.cloud.storage.CopyWriter)\n- [2.52.3](/java/docs/reference/google-cloud-storage/2.52.3/com.google.cloud.storage.CopyWriter)\n- [2.50.0](/java/docs/reference/google-cloud-storage/2.50.0/com.google.cloud.storage.CopyWriter)\n- [2.49.0](/java/docs/reference/google-cloud-storage/2.49.0/com.google.cloud.storage.CopyWriter)\n- [2.48.2](/java/docs/reference/google-cloud-storage/2.48.2/com.google.cloud.storage.CopyWriter)\n- [2.47.0](/java/docs/reference/google-cloud-storage/2.47.0/com.google.cloud.storage.CopyWriter)\n- [2.46.0](/java/docs/reference/google-cloud-storage/2.46.0/com.google.cloud.storage.CopyWriter)\n- [2.45.0](/java/docs/reference/google-cloud-storage/2.45.0/com.google.cloud.storage.CopyWriter)\n- [2.44.1](/java/docs/reference/google-cloud-storage/2.44.1/com.google.cloud.storage.CopyWriter)\n- [2.43.2](/java/docs/reference/google-cloud-storage/2.43.2/com.google.cloud.storage.CopyWriter)\n- [2.42.0](/java/docs/reference/google-cloud-storage/2.42.0/com.google.cloud.storage.CopyWriter)\n- [2.41.0](/java/docs/reference/google-cloud-storage/2.41.0/com.google.cloud.storage.CopyWriter)\n- [2.40.1](/java/docs/reference/google-cloud-storage/2.40.1/com.google.cloud.storage.CopyWriter)\n- [2.39.0](/java/docs/reference/google-cloud-storage/2.39.0/com.google.cloud.storage.CopyWriter)\n- [2.38.0](/java/docs/reference/google-cloud-storage/2.38.0/com.google.cloud.storage.CopyWriter)\n- [2.37.0](/java/docs/reference/google-cloud-storage/2.37.0/com.google.cloud.storage.CopyWriter)\n- [2.36.1](/java/docs/reference/google-cloud-storage/2.36.1/com.google.cloud.storage.CopyWriter)\n- [2.34.0](/java/docs/reference/google-cloud-storage/2.34.0/com.google.cloud.storage.CopyWriter)\n- [2.33.0](/java/docs/reference/google-cloud-storage/2.33.0/com.google.cloud.storage.CopyWriter)\n- [2.32.1](/java/docs/reference/google-cloud-storage/2.32.1/com.google.cloud.storage.CopyWriter)\n- [2.30.1](/java/docs/reference/google-cloud-storage/2.30.1/com.google.cloud.storage.CopyWriter)\n- [2.29.1](/java/docs/reference/google-cloud-storage/2.29.1/com.google.cloud.storage.CopyWriter)\n- [2.28.0](/java/docs/reference/google-cloud-storage/2.28.0/com.google.cloud.storage.CopyWriter)\n- [2.27.1](/java/docs/reference/google-cloud-storage/2.27.1/com.google.cloud.storage.CopyWriter)\n- [2.24.0](/java/docs/reference/google-cloud-storage/2.24.0/com.google.cloud.storage.CopyWriter)\n- [2.23.0](/java/docs/reference/google-cloud-storage/2.23.0/com.google.cloud.storage.CopyWriter)\n- [2.22.6](/java/docs/reference/google-cloud-storage/2.22.6/com.google.cloud.storage.CopyWriter)\n- [2.21.0](/java/docs/reference/google-cloud-storage/2.21.0/com.google.cloud.storage.CopyWriter)\n- [2.20.2](/java/docs/reference/google-cloud-storage/2.20.2/com.google.cloud.storage.CopyWriter)\n- [2.19.0](/java/docs/reference/google-cloud-storage/2.19.0/com.google.cloud.storage.CopyWriter)\n- [2.18.0](/java/docs/reference/google-cloud-storage/2.18.0/com.google.cloud.storage.CopyWriter)\n- [2.17.2](/java/docs/reference/google-cloud-storage/2.17.2/com.google.cloud.storage.CopyWriter)\n- [2.16.0](/java/docs/reference/google-cloud-storage/2.16.0/com.google.cloud.storage.CopyWriter)\n- [2.15.1](/java/docs/reference/google-cloud-storage/2.15.1/com.google.cloud.storage.CopyWriter)\n- [2.14.0](/java/docs/reference/google-cloud-storage/2.14.0/com.google.cloud.storage.CopyWriter)\n- [2.13.1](/java/docs/reference/google-cloud-storage/2.13.1/com.google.cloud.storage.CopyWriter)\n- [2.12.0](/java/docs/reference/google-cloud-storage/2.12.0/com.google.cloud.storage.CopyWriter)\n- [2.11.3](/java/docs/reference/google-cloud-storage/2.11.3/com.google.cloud.storage.CopyWriter)\n- [2.10.0](/java/docs/reference/google-cloud-storage/2.10.0/com.google.cloud.storage.CopyWriter)\n- [2.9.3](/java/docs/reference/google-cloud-storage/2.9.3/com.google.cloud.storage.CopyWriter)\n- [2.8.1](/java/docs/reference/google-cloud-storage/2.8.1/com.google.cloud.storage.CopyWriter)\n- [2.7.1](/java/docs/reference/google-cloud-storage/2.7.1/com.google.cloud.storage.CopyWriter)\n- [2.6.1](/java/docs/reference/google-cloud-storage/2.6.1/com.google.cloud.storage.CopyWriter)\n- [2.5.1](/java/docs/reference/google-cloud-storage/2.5.1/com.google.cloud.storage.CopyWriter)\n- [2.4.5](/java/docs/reference/google-cloud-storage/2.4.5/com.google.cloud.storage.CopyWriter)\n- [2.3.0](/java/docs/reference/google-cloud-storage/2.3.0/com.google.cloud.storage.CopyWriter)\n- [2.2.3](/java/docs/reference/google-cloud-storage/2.2.3/com.google.cloud.storage.CopyWriter)\n- [2.1.10](/java/docs/reference/google-cloud-storage/2.1.10/com.google.cloud.storage.CopyWriter) \n\n public abstract class CopyWriter implements Restorable\u003cCopyWriter\u003e\n\nGoogle Storage blob copy writer. A `CopyWriter` object allows to copy both blob's data and\ninformation. To override source blob's information supply a `BlobInfo` to the `\nCopyRequest` using either Storage.CopyRequest.Builder#setTarget(BlobInfo, Storage.BlobTargetOption...) or Storage.CopyRequest.Builder#setTarget(BlobInfo, Iterable).\n\nThis class holds the result of a copy request. If source and destination blobs share the same\nlocation and storage class the copy is completed in one RPC call otherwise one or more [#copyChunk](/java/docs/reference/google-cloud-storage/latest/com.google.cloud.storage.CopyWriter#com_google_cloud_storage_CopyWriter_copyChunk_) calls are necessary to complete the copy. In addition, [CopyWriter#getResult()](/java/docs/reference/google-cloud-storage/latest/com.google.cloud.storage.CopyWriter#com_google_cloud_storage_CopyWriter_getResult__)\ncan be used to automatically complete the copy and return information on the newly created blob.\nSee Also: [Rewrite](https://cloud.google.com/storage/docs/json_api/v1/objects/rewrite) \n\nInheritance\n-----------\n\n[java.lang.Object](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html) \\\u003e CopyWriter \n\nImplements\n----------\n\ncom.google.cloud.Restorable\\\u003ccom.google.cloud.storage.CopyWriter\\\u003e \n\nInherited Members\n-----------------\n\n[Object.clone()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#clone--) \n[Object.equals(Object)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#equals-java.lang.Object-) \n[Object.finalize()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#finalize--) \n[Object.getClass()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#getClass--) \n[Object.hashCode()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#hashCode--) \n[Object.notify()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notify--) \n[Object.notifyAll()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notifyAll--) \n[Object.toString()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#toString--) \n[Object.wait()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--) \n[Object.wait(long)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-) \n[Object.wait(long,int)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-)\n\nMethods\n-------\n\n### capture()\n\n public abstract RestorableState\u003cCopyWriter\u003e capture()\n\n### copyChunk()\n\n public abstract void copyChunk()\n\nCopies the next chunk of the blob. An RPC is issued only if copy has not finished yet ([#isDone](/java/docs/reference/google-cloud-storage/latest/com.google.cloud.storage.CopyWriter#com_google_cloud_storage_CopyWriter_isDone_) returns `false`).\n\n### getBlobSize()\n\n public abstract long getBlobSize()\n\nReturns the size of the blob being copied.\n\n### getResult()\n\n public abstract Blob getResult()\n\nReturns the updated information for the written blob. Calling this method when `isDone()`\nis `false` will block until all pending chunks are copied.\n\nThis method has the same effect of doing: \n\n\n while (!copyWriter.isDone()) {\n copyWriter.copyChunk();\n }\n \n### getTotalBytesCopied()\n\n public abstract long getTotalBytesCopied()\n\nReturns the number of bytes copied.\n\n### isDone()\n\n public abstract boolean isDone()\n\nReturns `true` if blob copy has finished, `false` otherwise."]]
