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=0ee621322c05a3ba7a64c3d7142e09e32edc6e8a;hb=6a39814272307d0207222c9229b0d765ac062bf0;hp=c132fa28e3dbcaa185789b674125716b0dbcd474;hpb=d14535ab85ced5cf9b1fcd5ca0e5d17ce267b573;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 c132fa28..0ee62132 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
@@ -1,9 +1,8 @@
-
 /*-
  * ========================LICENSE_START=================================
  * O-RAN-SC
  * %%
- * Copyright (C) 2019 Nordix Foundation
+ * 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.
@@ -21,38 +20,154 @@
 
 package org.oransc.policyagent.dmaap;
 
+import com.google.common.collect.Iterables;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+
+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 {
+@Component
+public class DmaapMessageConsumer {
 
-    /**
-     * The init method creates the MRConsumer with the properties passed from the Application Config
-     *
-     * @param properties
-     */
-    public void init();
+    protected static final Duration TIME_BETWEEN_DMAAP_RETRIES = Duration.ofSeconds(10);
 
-    /**
-     * This method process the message and call the respective Controller
-     *
-     * @param msg
-     * @throws Exception
-     */
-    public abstract void processMsg(String msg) throws Exception;
+    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;
+    }
 
     /**
-     * To check whether the DMAAP Listner is alive
+     * Starts the consumer. If there is a DMaaP configuration, it will start polling
+     * for messages. Otherwise it will check regularly for the configuration.
      *
-     * @return boolean
+     * @return the running thread, for test purposes.
      */
-    public boolean isAlive();
+    public Thread start() {
+        Thread thread = new Thread(this::messageHandlingLoop);
+        thread.start();
+        return thread;
+    }
 
-    /**
-     * It's a infinite loop run every configured seconds to fetch the message from DMAAP. This method can be stop by
-     * setting the alive flag to false
-     */
-    public void run();
+    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;
+    }
+
+    protected Iterable<String> fetchAllMessages() throws ServiceException {
+        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());
+        }
+    }
+
+    private void processMsg(String msg) {
+        logger.debug("Message Reveived from DMAAP : {}", msg);
+        getDmaapMessageHandler().handleDmaapMsg(msg);
+    }
+
+    protected DmaapMessageHandler getDmaapMessageHandler() {
+        if (this.dmaapMessageHandler == null) {
+            String agentBaseUrl = "http://localhost:" + this.localServerHttpPort;
+            AsyncRestClient agentClient =
+                new AsyncRestClient(agentBaseUrl, this.applicationConfig.getWebClientConfig());
+            AsyncRestClient producer = new AsyncRestClient(this.applicationConfig.getDmaapProducerTopicUrl(),
+                this.applicationConfig.getWebClientConfig());
+            this.dmaapMessageHandler = new DmaapMessageHandler(producer, agentClient);
+        }
+        return this.dmaapMessageHandler;
+    }
+
+    protected void sleep(Duration duration) {
+        try {
+            Thread.sleep(duration.toMillis());
+        } catch (Exception e) {
+            logger.error("Failed to put the thread to sleep", e);
+        }
+    }
+
+    protected AsyncRestClient getMessageRouterConsumer() {
+        return new AsyncRestClient("", this.applicationConfig.getWebClientConfig());
+    }
 
 }