Merge pull request #273 from assimbly/268-http-retry-impossible-to-se…

…e-response-body-from-5xx-responses

SetOriginalMessageProcessor - set and load originalHttpMessage when retry option is used on http component

dil/src/main/java/org/assimbly/dil/blocks/processors/SetOriginalMessageProcessor.java

@@ -0,0 +1,86 @@
+package org.assimbly.dil.blocks.processors;
+
+import org.apache.camel.Exchange;
+import org.apache.camel.Message;
+import org.apache.camel.Processor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SetOriginalMessageProcessor implements Processor {
+
+	private static String DOVETAIL_ORIGINAL_HTTP_MESSAGE_METHOD_PROP = "DOVETAIL_originalHttpMessageMethod";
+
+	private static String DOVETAIL_RETRY_ATTEMPTS_HEADER = "DOVETAIL_RetryAttempts";
+	private static String DOVETAIL_ORIGINAL_HTTP_MESSAGE_VARIABLE_ID_HEADER = "DOVETAIL_OriginalHttpMessageVariableId";
+
+	private static String CAMEL_GLOBAL_VARIABLE_PREFIX = "global:";
+
+	public enum HttpMethod {GET, SET, DEL}
+
+	protected Logger log = LoggerFactory.getLogger(getClass());
+
+	public void process(Exchange exchange) throws Exception {
+		String variableId;
+
+		String methodStr = (String) exchange.getProperty(DOVETAIL_ORIGINAL_HTTP_MESSAGE_METHOD_PROP);
+		HttpMethod originalHttpMessageMethod = getHttpMethod(methodStr);
+
+		switch (originalHttpMessageMethod) {
+			case GET:
+				// load the original http message into the current exchange from the camel global variable
+
+				// load retry attempts
+				Object retryAttempts = exchange.getMessage().getHeader(DOVETAIL_RETRY_ATTEMPTS_HEADER);
+				int retryAttemptsInt = (Integer)retryAttempts + 1;
+
+				// load original http message variable id
+				variableId = (String) exchange.getMessage().getHeader(DOVETAIL_ORIGINAL_HTTP_MESSAGE_VARIABLE_ID_HEADER);
+
+				// load original http message from global variable
+				Message originalHttpMessage = (Message) exchange.getVariable(CAMEL_GLOBAL_VARIABLE_PREFIX + variableId);
+
+				// set retry attempts
+				originalHttpMessage.setHeader(DOVETAIL_RETRY_ATTEMPTS_HEADER, retryAttemptsInt);
+
+				// load original http message into exchange
+				exchange.setMessage(originalHttpMessage);
+				break;
+
+			case SET:
+				// set the current exchange message as the original http message in the camel global variable
+
+				// set retry attempts to 1
+				exchange.getMessage().setHeader(DOVETAIL_RETRY_ATTEMPTS_HEADER, 0);
+
+				// using exchangeId as http message variable id
+				String exchangeId = exchange.getExchangeId();
+				// set original http message variable id
+				exchange.getMessage().setHeader(DOVETAIL_ORIGINAL_HTTP_MESSAGE_VARIABLE_ID_HEADER, exchangeId);
+
+				// set original http message on a global variable
+				exchange.setVariable(CAMEL_GLOBAL_VARIABLE_PREFIX + exchangeId, exchange.getMessage().copy());
+				break;
+
+			case DEL:
+				// delete the original http message from the camel global variables
+				variableId = (String) exchange.getMessage().getHeader(DOVETAIL_ORIGINAL_HTTP_MESSAGE_VARIABLE_ID_HEADER);
+				exchange.removeVariable(CAMEL_GLOBAL_VARIABLE_PREFIX + variableId);
+				break;
+
+			default:
+				// do nothing
+				break;
+
+		}
+	}
+
+	private HttpMethod getHttpMethod(String methodStr) {
+		try {
+			return HttpMethod.valueOf(methodStr);
+		} catch (IllegalArgumentException | NullPointerException e) {
+			log.error("Invalid HTTP method: " + methodStr + ". Using default: " + HttpMethod.GET);
+			return HttpMethod.GET;
+		}
+	}
+
+}

integration/src/main/java/org/assimbly/integration/impl/CamelIntegration.java

@@ -279,6 +279,7 @@ public void setDefaultBlocks() throws Exception {
 		registry.bind("ManageFlowProcessor", new ManageFlowProcessor());
 		registry.bind("multipartProcessor",new org.assimbly.multipart.processor.MultipartProcessor());
 		registry.bind("RoutingRulesProcessor", new RoutingRulesProcessor());
+		registry.bind("SetOriginalMessageProcessor", new SetOriginalMessageProcessor());
 		registry.bind("SetBodyProcessor", new SetBodyProcessor());
 		registry.bind("SetHeadersProcessor", new SetHeadersProcessor());
 		registry.bind("SetPatternProcessor", new SetPatternProcessor());