X-Git-Url: https://gerrit.o-ran-sc.org/r/gitweb?a=blobdiff_plain;f=policy-agent%2Fsrc%2Fmain%2Fjava%2Forg%2Foransc%2Fpolicyagent%2Fdmaap%2FDmaapMessageConsumer.java;h=e141babd25e2e62d3620c503d9c89c259d3616f9;hb=4e7db50d7fb3fd2c7101520f00f0f0b4baf9bddc;hp=7e77528796fd4947e7769d59477c5e10e2c47d46;hpb=ff56d2600d074ac0a4473c81b8193004a316c2f8;p=nonrtric.git

diff --git a/policy-agent/src/main/java/org/oransc/policyagent/dmaap/DmaapMessageConsumer.java b/policy-agent/src/main/java/org/oransc/policyagent/dmaap/DmaapMessageConsumer.java
index 7e775287..e141babd 100644
--- a/policy-agent/src/main/java/org/oransc/policyagent/dmaap/DmaapMessageConsumer.java
+++ b/policy-agent/src/main/java/org/oransc/policyagent/dmaap/DmaapMessageConsumer.java
@@ -1,22 +1,173 @@
+/*-
+ * ========================LICENSE_START=================================
+ * O-RAN-SC
+ * %%
+ * Copyright (C) 2020 Nordix Foundation
+ * %%
+ * 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.oransc.policyagent.dmaap;
 
-import java.util.Properties;
+import com.google.common.collect.Iterables;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.oransc.policyagent.clients.AsyncRestClient;
+import org.oransc.policyagent.configuration.ApplicationConfig;
+import org.oransc.policyagent.exceptions.ServiceException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
 
 /**
- * The Dmaap consumer which has the base methods to be implemented by any class
- * which implements this interface
+ * The class fetches incoming requests from DMAAP. It uses the timeout parameter
+ * that lets the MessageRouter keep the connection with the Kafka open until
+ * requests are sent in.
+ *
+ * <p>
+ * this service will regularly check the configuration and start polling DMaaP
+ * if the configuration is added. If the DMaaP configuration is removed, then
+ * the service will stop polling and resume checking for configuration.
  *
+ * <p>
+ * Each received request is processed by {@link DmaapMessageHandler}.
  */
-public interface DmaapMessageConsumer extends Runnable {
+@Component
+public class DmaapMessageConsumer {
+
+    protected static final Duration TIME_BETWEEN_DMAAP_RETRIES = Duration.ofSeconds(10);
+
+    private static final Logger logger = LoggerFactory.getLogger(DmaapMessageConsumer.class);
+
+    private final ApplicationConfig applicationConfig;
+
+    private DmaapMessageHandler dmaapMessageHandler = null;
+
+    @Value("${server.http-port}")
+    private int localServerHttpPort;
+
+    @Autowired
+    public DmaapMessageConsumer(ApplicationConfig applicationConfig) {
+        this.applicationConfig = applicationConfig;
+    }
+
+    /**
+     * Starts the consumer. If there is a DMaaP configuration, it will start polling
+     * for messages. Otherwise it will check regularly for the configuration.
+     *
+     * @return the running thread, for test purposes.
+     */
+    public Thread start() {
+        Thread thread = new Thread(this::messageHandlingLoop);
+        thread.start();
+        return thread;
+    }
+
+    private void messageHandlingLoop() {
+        while (!isStopped()) {
+            try {
+                if (isDmaapConfigured()) {
+                    Iterable<String> dmaapMsgs = fetchAllMessages();
+                    if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
+                        logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
+                        for (String msg : dmaapMsgs) {
+                            processMsg(msg);
+                        }
+                    }
+                } else {
+                    sleep(TIME_BETWEEN_DMAAP_RETRIES); // wait for configuration
+                }
+            } catch (Exception e) {
+                logger.warn("{}", e.getMessage());
+                sleep(TIME_BETWEEN_DMAAP_RETRIES);
+            }
+        }
+    }
+
+    protected boolean isStopped() {
+        return false;
+    }
+
+    protected boolean isDmaapConfigured() {
+        String producerTopicUrl = applicationConfig.getDmaapProducerTopicUrl();
+        String consumerTopicUrl = applicationConfig.getDmaapConsumerTopicUrl();
+        return (!producerTopicUrl.isEmpty() && !consumerTopicUrl.isEmpty());
+    }
+
+    private static List<String> parseMessages(String jsonString) {
+        JsonArray arrayOfMessages = JsonParser.parseString(jsonString).getAsJsonArray();
+        List<String> result = new ArrayList<>();
+        for (JsonElement element : arrayOfMessages) {
+            if (element.isJsonPrimitive()) {
+                result.add(element.getAsString());
+            } else {
+                String messageAsString = element.toString();
+                result.add(messageAsString);
+            }
+        }
+        return result;
+    }
 
-    public void init(Properties baseProperties);
+    protected Iterable<String> fetchAllMessages() throws ServiceException, IOException {
+        String topicUrl = this.applicationConfig.getDmaapConsumerTopicUrl();
+        AsyncRestClient consumer = getMessageRouterConsumer();
+        ResponseEntity<String> response = consumer.getForEntity(topicUrl).block();
+        logger.debug("DMaaP consumer received {} : {}", response.getStatusCode(), response.getBody());
+        if (response.getStatusCode().is2xxSuccessful()) {
+            return parseMessages(response.getBody());
+        } else {
+            throw new ServiceException("Cannot fetch because of Error respons: " + response.getStatusCode().toString()
+                + " " + response.getBody());
+        }
+    }
 
-    public abstract void processMsg(String msg) throws Exception;
+    private void processMsg(String msg) throws IOException {
+        logger.debug("Message Reveived from DMAAP : {}", msg);
+        getDmaapMessageHandler().handleDmaapMsg(msg);
+    }
 
-    public boolean isReady();
+    protected DmaapMessageHandler getDmaapMessageHandler() throws IOException {
+        if (this.dmaapMessageHandler == null) {
+            String agentBaseUrl = "http://localhost:" + this.localServerHttpPort;
+            AsyncRestClient agentClient = new AsyncRestClient(agentBaseUrl);
+            AsyncRestClient producer = new AsyncRestClient(this.applicationConfig.getDmaapProducerTopicUrl(),
+                this.applicationConfig.getWebClientConfig());
+            this.dmaapMessageHandler = new DmaapMessageHandler(producer, agentClient);
+        }
+        return this.dmaapMessageHandler;
+    }
 
-    public boolean isRunning();
+    protected void sleep(Duration duration) {
+        try {
+            Thread.sleep(duration.toMillis());
+        } catch (Exception e) {
+            logger.error("Failed to put the thread to sleep", e);
+        }
+    }
 
-    public void stopConsumer();
+    protected AsyncRestClient getMessageRouterConsumer() {
+        return new AsyncRestClient("", this.applicationConfig.getWebClientConfig());
+    }
 
 }