fixes #2337 update req/res transformer interceptor to handle the error result from the plugins (#2338)

Author: stevehu

request-transformer/src/main/java/com/networknt/reqtrans/RequestTransformerInterceptor.java

@@ -25,6 +25,8 @@
 import java.nio.charset.StandardCharsets;
 import java.util.*;
 
+import static com.networknt.utility.Constants.ERROR_MESSAGE;
+
 /**
  * Transforms the request body of an active request being processed.
  * This is executed by RequestInterceptorExecutionHandler. Also, this class will be responsible for
@@ -36,6 +38,7 @@
 public class RequestTransformerInterceptor implements RequestInterceptor {
     static final Logger logger = LoggerFactory.getLogger(RequestTransformerInterceptor.class);
     static final String REQUEST_TRANSFORM = "request-transform";
+    static final String GENERIC_EXCEPTION = "ERR10014";
 
     private final RequestTransformerConfig config;
     private volatile HttpHandler next;
@@ -253,7 +256,7 @@ public void handleRequest(HttpServerExchange exchange) throws Exception {
                                     case "validationError":
                                         // If the rule engine returns any validationError entry, stop the chain and send the res.
                                         // this can be either XML or JSON or TEXT. Just make sure it matches the content type
-                                        String errorMessage = (String)result.get("errorMessage");
+                                        String errorMessage = (String)result.get(ERROR_MESSAGE);
                                         String contentType = (String)result.get("contentType");
                                         int statusCode = (Integer)result.get("statusCode");
                                         if(logger.isTraceEnabled()) logger.trace("Entry key validationError with errorMessage {} contentType {} statusCode {}");
@@ -263,6 +266,12 @@ public void handleRequest(HttpServerExchange exchange) throws Exception {
                                         break;
                                 }
                             }
+                        } else {
+                            // The plugin returns false, and it indicates an error has happened. We need to send this error
+                            // message to the caller and stop the chain immediately by setting the exchange status.
+                            String errorMessage = (String)result.get(ERROR_MESSAGE);
+                            if(logger.isTraceEnabled()) logger.trace("Error message {} returns from the plugin", errorMessage);
+                            setExchangeStatus(exchange, GENERIC_EXCEPTION, errorMessage);
                         }
                     }
                 }

response-transformer/src/main/java/com/networknt/restrans/ResponseTransformerInterceptor.java

@@ -25,6 +25,8 @@
 import java.util.List;
 import java.util.Map;
 
+import static com.networknt.utility.Constants.ERROR_MESSAGE;
+
 /**
  * This is a generic middleware handler to manipulate response based on rule-engine rules so that it can be much more
  * flexible than any other handlers like the header handler to manipulate the headers. The rules will be loaded from
@@ -54,6 +56,7 @@ public class ResponseTransformerInterceptor implements ResponseInterceptor {
 
     private static final String STARTUP_HOOK_NOT_LOADED = "ERR11019";
     private static final String RESPONSE_TRANSFORM = "response-transform";
+    static final String GENERIC_EXCEPTION = "ERR10014";
 
     private final ResponseTransformerConfig config;
     private volatile HttpHandler next;
@@ -191,6 +194,11 @@ public void handleRequest(HttpServerExchange exchange) throws Exception {
                             break;
                     }
                 }
+            } else {
+                // The finalResult is false to indicate there is an error in the plugin action. Set the exchange to stop the chain.
+                String errorMessage = (String)result.get(ERROR_MESSAGE);
+                if(logger.isTraceEnabled()) logger.trace("Error message {} returns from the plugin", errorMessage);
+                setExchangeStatus(exchange, GENERIC_EXCEPTION, errorMessage);
             }
         }
         if (logger.isDebugEnabled()) logger.trace("ResponseTransformerInterceptor.handleRequest ends.");

restrans-config/src/main/java/com/networknt/restrans/ResponseTransformerConfig.java

@@ -21,7 +21,7 @@ public class ResponseTransformerConfig {
     private static final String APPLIED_PATH_PREFIXES = "appliedPathPrefixes";
 
     private Map<String, Object> mappedConfig;
-    private Config config;
+    private final Config config;
     private boolean enabled;
     private boolean requiredContent;
     private String defaultBodyEncoding;

utility/src/main/java/com/networknt/utility/Constants.java

@@ -131,4 +131,7 @@ public class Constants {
     // framework
     public static final String LIGHT_4J = "Light4j";
     public static final String SPRING_BOOT = "SpringBoot";
+
+    // plugin error message
+    public static final String ERROR_MESSAGE = "errorMessage";
 }