Example of getting the blob's latest information, if its generation does not match the - * {@link Blob#getGeneration()} value, otherwise a {@link StorageException} is thrown. + *
{@code options} parameter can contain the preconditions. For example, the user might want to + * get the blob properties only if the content has not been updated externally. {@code + * StorageException} with the code {@code 412} is thrown if preconditions fail. + * + *
Example of retrieving the blob's latest information only if the content is not updated + * externally: * *
{@code
- * Blob latestBlob = blob.reload(BlobSourceOption.generationNotMatch());
- * if (latestBlob == null) {
- * // the blob was not found
+ * Blob blob = storage.get(BlobId.of(bucketName, blobName));
+ *
+ * doSomething();
+ *
+ * try {
+ * blob = blob.reload(Blob.BlobSourceOption.generationMatch());
+ * } catch (StorageException e) {
+ * if (e.getCode() == 412) {
+ * // the content was updated externally
+ * } else {
+ * throw e;
+ * }
* }
* }
*
- * @param options blob read options
- * @return a {@code Blob} object with latest information or {@code null} if not found
+ * @param options preconditions to use on reload, see https://cloud.google.com/storage/docs/json_api/v1/objects/get
+ * for more information.
+ * @return a {@code Blob} object with latest information or {@code null} if no longer exists.
* @throws StorageException upon failure
*/
public Blob reload(BlobSourceOption... options) {
- return storage.get(getBlobId(), toGetOptions(this, options));
+ // BlobId with generation unset is needed to retrieve the latest version of the Blob
+ BlobId idWithoutGeneration = BlobId.of(getBucket(), getName());
+ return storage.get(idWithoutGeneration, toGetOptions(this, options));
}
/**
@@ -730,6 +747,7 @@ public ReadChannel reader(BlobSourceOption... options) {
* } catch (IOException ex) {
* // handle exception
* }
+ * blob = blob.reload();
* }
*
* @param options target blob options
diff --git a/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java b/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
index 51d606c2b..7ff384fb9 100644
--- a/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
+++ b/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
@@ -129,7 +129,11 @@ public class BlobTest {
.setRetentionExpirationTime(RETENTION_EXPIRATION_TIME)
.build();
private static final BlobInfo BLOB_INFO =
- BlobInfo.newBuilder("b", "n").setMetageneration(42L).build();
+ BlobInfo.newBuilder("b", "n", 12345678L).setMetageneration(42L).build();
+ private static final BlobInfo BLOB_INFO_NO_GENERATION =
+ BlobInfo.newBuilder(BLOB_INFO.getBucket(), BLOB_INFO.getName())
+ .setMetageneration(42L)
+ .build();
private static final BlobInfo DIRECTORY_INFO =
BlobInfo.newBuilder("b", "n/").setSize(0L).setIsDirectory(true).build();
private static final String BASE64_KEY = "JVzfVl8NLD9FjedFuStegjRfES5ll5zc59CIXw572OA=";
@@ -233,7 +237,7 @@ public void testReload() throws Exception {
initializeExpectedBlob(2);
Blob expectedReloadedBlob = expectedBlob.toBuilder().setCacheControl("c").build();
expect(storage.getOptions()).andReturn(mockOptions);
- expect(storage.get(BLOB_INFO.getBlobId(), new Storage.BlobGetOption[0]))
+ expect(storage.get(BLOB_INFO_NO_GENERATION.getBlobId(), new Storage.BlobGetOption[0]))
.andReturn(expectedReloadedBlob);
replay(storage);
initializeBlob();
@@ -245,7 +249,8 @@ public void testReload() throws Exception {
public void testReloadNull() throws Exception {
initializeExpectedBlob(1);
expect(storage.getOptions()).andReturn(mockOptions);
- expect(storage.get(BLOB_INFO.getBlobId(), new Storage.BlobGetOption[0])).andReturn(null);
+ expect(storage.get(BLOB_INFO_NO_GENERATION.getBlobId(), new Storage.BlobGetOption[0]))
+ .andReturn(null);
replay(storage);
initializeBlob();
Blob reloadedBlob = blob.reload();
@@ -258,7 +263,8 @@ public void testReloadWithOptions() throws Exception {
Blob expectedReloadedBlob = expectedBlob.toBuilder().setCacheControl("c").build();
Storage.BlobGetOption[] options = {Storage.BlobGetOption.metagenerationMatch(42L)};
expect(storage.getOptions()).andReturn(mockOptions);
- expect(storage.get(BLOB_INFO.getBlobId(), options)).andReturn(expectedReloadedBlob);
+ expect(storage.get(BLOB_INFO_NO_GENERATION.getBlobId(), options))
+ .andReturn(expectedReloadedBlob);
replay(storage);
initializeBlob();
Blob updatedBlob = blob.reload(BlobSourceOption.metagenerationMatch());
@@ -301,8 +307,8 @@ public void testCopyToBucket() throws Exception {
initializeBlob();
CopyWriter returnedCopyWriter = blob.copyTo("bt");
assertEquals(copyWriter, returnedCopyWriter);
- assertEquals(capturedCopyRequest.getValue().getSource(), blob.getBlobId());
- assertEquals(capturedCopyRequest.getValue().getTarget(), target);
+ assertEquals(BLOB_INFO_NO_GENERATION.getBlobId(), capturedCopyRequest.getValue().getSource());
+ assertEquals(target, capturedCopyRequest.getValue().getTarget());
assertFalse(capturedCopyRequest.getValue().overrideInfo());
assertTrue(capturedCopyRequest.getValue().getSourceOptions().isEmpty());
assertTrue(capturedCopyRequest.getValue().getTargetOptions().isEmpty());
@@ -320,8 +326,8 @@ public void testCopyTo() throws Exception {
initializeBlob();
CopyWriter returnedCopyWriter = blob.copyTo("bt", "nt");
assertEquals(copyWriter, returnedCopyWriter);
- assertEquals(capturedCopyRequest.getValue().getSource(), blob.getBlobId());
- assertEquals(capturedCopyRequest.getValue().getTarget(), target);
+ assertEquals(BLOB_INFO_NO_GENERATION.getBlobId(), capturedCopyRequest.getValue().getSource());
+ assertEquals(target, capturedCopyRequest.getValue().getTarget());
assertFalse(capturedCopyRequest.getValue().overrideInfo());
assertTrue(capturedCopyRequest.getValue().getSourceOptions().isEmpty());
assertTrue(capturedCopyRequest.getValue().getTargetOptions().isEmpty());
@@ -340,8 +346,8 @@ public void testCopyToBlobId() throws Exception {
initializeBlob();
CopyWriter returnedCopyWriter = blob.copyTo(targetId);
assertEquals(copyWriter, returnedCopyWriter);
- assertEquals(capturedCopyRequest.getValue().getSource(), blob.getBlobId());
- assertEquals(capturedCopyRequest.getValue().getTarget(), target);
+ assertEquals(BLOB_INFO_NO_GENERATION.getBlobId(), capturedCopyRequest.getValue().getSource());
+ assertEquals(target, capturedCopyRequest.getValue().getTarget());
assertFalse(capturedCopyRequest.getValue().overrideInfo());
assertTrue(capturedCopyRequest.getValue().getSourceOptions().isEmpty());
assertTrue(capturedCopyRequest.getValue().getTargetOptions().isEmpty());
diff --git a/google-cloud-storage/src/test/java/com/google/cloud/storage/it/ITStorageTest.java b/google-cloud-storage/src/test/java/com/google/cloud/storage/it/ITStorageTest.java
index e1fb52603..2bbb20ce7 100644
--- a/google-cloud-storage/src/test/java/com/google/cloud/storage/it/ITStorageTest.java
+++ b/google-cloud-storage/src/test/java/com/google/cloud/storage/it/ITStorageTest.java
@@ -21,6 +21,7 @@
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
@@ -3243,4 +3244,33 @@ public void testSignedPostPolicyV4() throws Exception {
assertEquals("hello world", new String(storage.get(BUCKET, "my-object").getContent()));
}
+
+ @Test
+ public void testBlobReload() throws Exception {
+ String blobName = "test-blob-reload";
+ BlobId blobId = BlobId.of(BUCKET, blobName);
+ BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
+ Blob blob = storage.create(blobInfo, new byte[] {0, 1, 2});
+
+ Blob blobUnchanged = blob.reload();
+ assertEquals(blob, blobUnchanged);
+
+ blob.writer().close();
+ try {
+ blob.reload(Blob.BlobSourceOption.generationMatch());
+ fail("StorageException was expected");
+ } catch (StorageException e) {
+ assertEquals(412, e.getCode());
+ assertEquals("Precondition Failed", e.getMessage());
+ }
+
+ Blob updated = blob.reload();
+ assertEquals(blob.getBucket(), updated.getBucket());
+ assertEquals(blob.getName(), updated.getName());
+ assertNotEquals(blob.getGeneration(), updated.getGeneration());
+ assertEquals(new Long(0), updated.getSize());
+
+ updated.delete();
+ assertNull(updated.reload());
+ }
}