1 files changed, 59 insertions, 0 deletions
diff --git a/rest-services/http-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/retry/RetryIntervalExtractor.java b/rest-services/http-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/retry/RetryIntervalExtractor.java
new file mode 100644
index 00000000..0e2c875a
--- /dev/null
+++ b/rest-services/http-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/retry/RetryIntervalExtractor.java
@@ -0,0 +1,59 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2021 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http.retry;
+
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.vavr.Tuple;
+import io.vavr.Value;
+import io.vavr.collection.Multimap;
+import io.vavr.control.Option;
+import io.vavr.control.Try;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpResponse;
+
+import java.time.Duration;
+
+class RetryIntervalExtractor {
+
+    private static final String RETRY_AFTER_HEADER = HttpHeaderNames.RETRY_AFTER.toString();
+    private static final int PAYLOAD_TOO_LARGE_HTTP_CODE = HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE.code();
+
+    Option<Duration> extractDelay(HttpResponse response) {
+        return response.statusCode() == PAYLOAD_TOO_LARGE_HTTP_CODE
+                ? extractDelay(response.headers())
+                : Option.none();
+    }
+
+    private Option<Duration> extractDelay(Multimap<String, String> headers) {
+        return headers
+                .map((key, value) -> Tuple.of(key.toLowerCase(), value))
+                .get(RETRY_AFTER_HEADER)
+                .toStream()
+                .flatMap(Value::toStream)
+                .map(this::parse)
+                .find(d -> d >= 0)
+                .map(Duration::ofSeconds);
+    }
+
+    private int parse(String str) {
+        return Try.of(() -> Integer.parseInt(str)).getOrElse(-1);
+    }
+}