Abort method for S3OutputStream for ability to cancel the upload midway through

spring-cloud-aws-s3/src/main/java/io/awspring/cloud/s3/AbstractTempFileS3OutputStream.java

@@ -121,6 +121,17 @@ public void flush() throws IOException {
 		localOutputStream.flush();
 	}
 
+	@Override
+	public void abort() throws IOException {
+		if (closed) {
+			throw new IllegalStateException("Stream is already closed. Too late to abort.");
+		}
+
+		localOutputStream.close();
+		closed = true;
+		deleteTempFile();
+	}
+
 	@Override
 	public void close() throws IOException {
 		if (closed) {
@@ -145,19 +156,22 @@ public void close() throws IOException {
 				}
 			}
 			this.upload(builder.build());
-			boolean result = file.delete();
-
-			if (!result) {
-				getLogger().warn(String.format("Temporary file %s could not be deleted", file.getPath()));
-			}
+			deleteTempFile();
 		}
 		catch (Exception se) {
-			getLogger().error(
-					String.format("Failed to upload %s. Temporary file @%s", location.getObject(), file.getPath()));
+			getLogger().error("Failed to upload {}. Temporary file @{}", location.getObject(), file.getPath());
 			throw new UploadFailedException(file.getPath(), se);
 		}
 	}
 
+	private void deleteTempFile() {
+		boolean result = file.delete();
+
+		if (!result) {
+			getLogger().warn("Temporary file {} could not be deleted", file.getPath());
+		}
+	}
+
 	protected abstract void upload(PutObjectRequest putObjectRequest);
 
 	protected Logger getLogger() {

spring-cloud-aws-s3/src/main/java/io/awspring/cloud/s3/InMemoryBufferingS3OutputStream.java

@@ -117,6 +117,19 @@ public void write(int b) {
 		}
 	}
 
+	@Override
+	public void abort() {
+		synchronized (this.monitor) {
+			if (isClosed()) {
+				throw new IllegalStateException("Stream is already closed. Too late to abort.");
+			}
+			if (isMultiPartUpload()) {
+				abortMultiPartUpload(multipartUploadResponse);
+			}
+			outputStream = null;
+		}
+	}
+
 	@Override
 	public void close() {
 		synchronized (this.monitor) {

spring-cloud-aws-s3/src/main/java/io/awspring/cloud/s3/S3OutputStream.java

@@ -15,6 +15,7 @@
  */
 package io.awspring.cloud.s3;
 
+import java.io.IOException;
 import java.io.OutputStream;
 
 /**
@@ -25,4 +26,9 @@
  */
 public abstract class S3OutputStream extends OutputStream {
 
+	/**
+	 * Cancels the upload and cleans up temporal resources (temp files, partial multipart upload).
+	 */
+	public void abort() throws IOException {
+	}
 }

spring-cloud-aws-s3/src/test/java/io/awspring/cloud/s3/DiskBufferingS3OutputStreamTests.java

@@ -19,6 +19,7 @@
 import static org.assertj.core.api.Assertions.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -70,4 +71,16 @@ void throwsExceptionWhenUploadFails() throws IOException {
 		}
 	}
 
+	@Test
+	void abortsWhenExplicitlyInvoked() throws IOException {
+		S3Client s3Client = mock(S3Client.class);
+
+		try (DiskBufferingS3OutputStream diskBufferingS3OutputStream = new DiskBufferingS3OutputStream(
+			new Location("bucket", "key"), s3Client, null)) {
+			diskBufferingS3OutputStream.write("hello".getBytes(StandardCharsets.UTF_8));
+			diskBufferingS3OutputStream.abort();
+		}
+
+		verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
+	}
 }

spring-cloud-aws-s3/src/test/java/io/awspring/cloud/s3/InMemoryBufferingS3OutputStreamTests.java

@@ -168,4 +168,74 @@ void abortsWhenCompletingMultipartUploadFails() throws IOException {
 			assertThat(requestCaptor.getValue().uploadId()).isEqualTo("uploadId");
 		}
 	}
+
+	@Test
+	void abortsWhenExplicitlyInvoked() throws IOException {
+		when(s3Client.createMultipartUpload(any(CreateMultipartUploadRequest.class)))
+				.thenReturn(CreateMultipartUploadResponse.builder().uploadId("uploadId").build());
+
+		when(s3Client.uploadPart(any(UploadPartRequest.class), any(RequestBody.class)))
+				.thenReturn(UploadPartResponse.builder().build());
+
+		when(s3Client.completeMultipartUpload(any(CompleteMultipartUploadRequest.class)))
+				.thenThrow(SdkException.builder().build());
+
+		final byte[] content = new byte[DEFAULT_BUFFER_CAPACITY_IN_BYTES + 1];
+
+		try (InMemoryBufferingS3OutputStream outputStream = new InMemoryBufferingS3OutputStream(
+			new Location("bucket", "key", null), s3Client, null, null, DEFAULT_BUFFER_CAPACITY)) {
+			new Random().nextBytes(content);
+			outputStream.write(content);
+			outputStream.abort();
+		}
+		final ArgumentCaptor<AbortMultipartUploadRequest> requestCaptor = ArgumentCaptor
+				.forClass(AbortMultipartUploadRequest.class);
+
+		verify(s3Client, times(1)).abortMultipartUpload(requestCaptor.capture());
+		assertThat(requestCaptor.getValue().bucket()).isEqualTo("bucket");
+		assertThat(requestCaptor.getValue().key()).isEqualTo("key");
+		assertThat(requestCaptor.getValue().uploadId()).isEqualTo("uploadId");
+	}
+
+	@Test
+	void abortsWhenInvokedBeforeWriting() {
+		try (InMemoryBufferingS3OutputStream outputStream = new InMemoryBufferingS3OutputStream(
+				new Location("bucket", "key", null), s3Client, null, null, DEFAULT_BUFFER_CAPACITY)) {
+			outputStream.abort();
+		}
+
+		verify(s3Client, never()).createMultipartUpload(any(CreateMultipartUploadRequest.class));
+		verify(s3Client, never()).abortMultipartUpload(any(AbortMultipartUploadRequest.class));
+	}
+
+	@Test
+	void failsWhenAbortingAfterClosing() {
+		InMemoryBufferingS3OutputStream outputStream = null;
+		try {
+			outputStream = new InMemoryBufferingS3OutputStream(new Location("bucket", "key", null), s3Client, null,
+					null, DEFAULT_BUFFER_CAPACITY);
+		}
+		finally {
+			assertThat(outputStream).isNotNull();
+			outputStream.close();
+			try {
+				outputStream.abort();
+				fail("IllegalStateException should be thrown.");
+			}
+			catch (IllegalStateException e) {
+				final ArgumentCaptor<PutObjectRequest> requestCaptor = ArgumentCaptor.forClass(PutObjectRequest.class);
+				final ArgumentCaptor<RequestBody> bodyCaptor = ArgumentCaptor.forClass(RequestBody.class);
+
+				verify(s3Client, times(1)).putObject(requestCaptor.capture(), bodyCaptor.capture());
+
+				assertThat(requestCaptor.getValue().bucket()).isEqualTo("bucket");
+				assertThat(requestCaptor.getValue().key()).isEqualTo("key");
+				assertThat(requestCaptor.getValue().contentLength()).isEqualTo(0);
+				assertThat(requestCaptor.getValue().contentMD5()).isNotNull();
+
+				verify(s3Client, never()).createMultipartUpload(any(CreateMultipartUploadRequest.class));
+				verify(s3Client, never()).abortMultipartUpload(any(AbortMultipartUploadRequest.class));
+			}
+		}
+	}
 }