Add listAllObjects method to S3Template (#1443)

Author: Tooa

spring-cloud-aws-s3/src/main/java/io/awspring/cloud/s3/S3Operations.java

@@ -80,6 +80,15 @@ public interface S3Operations {
 	 */
 	boolean objectExists(String bucketName, String key);
 
+	/**
+	 * Returns some or all (up to 1,000) of the objects in a bucket. Does not handle pagination. If you need pagination
+	 * you should use {@link S3PathMatchingResourcePatternResolver} or {@link S3Client}
+	 *
+	 * @param bucketName - the bucket name
+	 * @return list of {@link S3Resource}
+	 */
+	List<S3Resource> listAllObjects(String bucketName);
+
 	/**
 	 * Returns some or all (up to 1,000) of the objects in a bucket. Does not handle pagination. If you need pagination
 	 * you should use {@link S3PathMatchingResourcePatternResolver} or {@link S3Client}

spring-cloud-aws-s3/src/main/java/io/awspring/cloud/s3/S3Template.java

@@ -116,6 +116,11 @@ public boolean objectExists(String bucketName, String key) {
 		return true;
 	}
 
+	@Override
+	public List<S3Resource> listAllObjects(String bucketName) {
+		return listObjects(bucketName, "");
+	}
+
 	@Override
 	public List<S3Resource> listObjects(String bucketName, String prefix) {
 		Assert.notNull(bucketName, "bucketName is required");

spring-cloud-aws-s3/src/test/java/io/awspring/cloud/s3/S3TemplateIntegrationTests.java

@@ -190,6 +190,22 @@ void whenObjectNotExistsShouldReturnFalse() {
 		assertThat(existsObject2).isFalse();
 	}
 
+	@Test
+	void listAllObjects() throws IOException {
+		client.putObject(r -> r.bucket(BUCKET_NAME).key("hello-en.txt"), RequestBody.fromString("hello"));
+		client.putObject(r -> r.bucket(BUCKET_NAME).key("hello-fr.txt"), RequestBody.fromString("bonjour"));
+		client.putObject(r -> r.bucket(BUCKET_NAME).key("bye.txt"), RequestBody.fromString("bye"));
+
+		List<S3Resource> resources = s3Template.listAllObjects(BUCKET_NAME);
+		assertThat(resources.size()).isEqualTo(3);
+
+		// According to the S3Client doc : "Objects are returned sorted in an ascending order of the respective key
+		// names in the list."
+		assertThat(resources).extracting(S3Resource::getInputStream)
+				.map(is -> new String(is.readAllBytes(), StandardCharsets.UTF_8))
+				.containsExactly("bye", "hello", "bonjour");
+	}
+
 	@Test
 	void listObjects() throws IOException {
 		client.putObject(r -> r.bucket(BUCKET_NAME).key("hello-en.txt"), RequestBody.fromString("hello"));