Add configurable s3Key as an optional parameter. (#14)

* configure s3key by using additinal parameter for storeOriginalPayload function (by overloading the params)

Co-authored-by: Ramesh Bugatha <bugatha@amazon.com>

Author: rbugatha

src/main/java/software/amazon/payloadoffloading/PayloadStore.java

@@ -21,6 +21,21 @@ public interface PayloadStore {
      */
     String storeOriginalPayload(String payload, Long payloadContentSize);
 
+    /**
+     * Stores payload in a store that has higher payload size limit than that is supported by original payload store.
+     *
+     * @param payload
+     * @param payloadContentSize
+     * @param key  custom s3Key.
+     * @return a pointer that must be used to retrieve the original payload later.
+     * @throws AmazonClientException  If any internal errors are encountered on the client side while
+     *                                attempting to make the request or handle the response. For example
+     *                                if a network connection is not available.
+     * @throws AmazonServiceException If an error response is returned by actual PayloadStore indicating
+     *                                either a problem with the data in the request, or a server side issue.
+     */
+    String storeOriginalPayload(String payload, Long payloadContentSize, String key);
+
     /**
      * Retrieves the original payload using the given payloadPointer. The pointer must
      * have been obtained using {@link storeOriginalPayload}

src/main/java/software/amazon/payloadoffloading/S3BackedPayloadStore.java

@@ -21,7 +21,12 @@ public S3BackedPayloadStore(S3Dao s3Dao, String s3BucketName) {
 
     @Override
     public String storeOriginalPayload(String payload, Long payloadContentSize) {
-        String s3Key = UUID.randomUUID().toString();
+        return storeOriginalPayload(payload, payloadContentSize, null);
+    }
+
+    @Override
+    public String storeOriginalPayload(String payload, Long payloadContentSize, String key) {
+        String s3Key = (key!=null) ? key : UUID.randomUUID().toString();
 
         // Store the payload content in S3.
         s3Dao.storeTextInS3(s3BucketName, s3Key, payload, payloadContentSize);

src/test/java/software/amazon/payloadoffloading/S3BackedPayloadStoreTest.java

@@ -50,6 +50,17 @@ public void testStoreOriginalPayloadOnSuccess() {
         assertEquals(expectedPayloadPointer.toJson(), actualPayloadPointer);
     }
 
+    @Test
+    public void testStoreOriginalPayloadWithS3KeyOnSuccess() {
+        String actualPayloadPointer = payloadStore.storeOriginalPayload(ANY_PAYLOAD, ANY_PAYLOAD_LENGTH, ANY_S3_KEY);
+
+        verify(s3Dao, times(1)).storeTextInS3(eq(S3_BUCKET_NAME), eq(ANY_S3_KEY),
+                eq(ANY_PAYLOAD), eq(ANY_PAYLOAD_LENGTH));
+
+        PayloadS3Pointer expectedPayloadPointer = new PayloadS3Pointer(S3_BUCKET_NAME, ANY_S3_KEY);
+        assertEquals(expectedPayloadPointer.toJson(), actualPayloadPointer);
+    }
+
     @Test
     public void testStoreOriginalPayloadDoesAlwaysCreateNewObjects() {
         //Store any payload