FT-800 Added better message logging for unhandled exceptions

webapp/src/main/java/org/apache/atlas/web/errors/ExceptionMapperUtil.java

@@ -17,15 +17,80 @@
  */
 package org.apache.atlas.web.errors;
 
+import org.apache.atlas.type.AtlasType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.HashMap;
 
 public class ExceptionMapperUtil {
     protected static final Logger LOGGER = LoggerFactory.getLogger(ExceptionMapperUtil.class);
 
     @SuppressWarnings("UnusedParameters")
     protected static String formatErrorMessage(long id, Exception exception) {
-        return String.format("There was an error processing your request. It has been logged (ID %016x).", id);
+        if (exception == null) {
+            // If the exception is null, return a minimal error message
+            Map<String, Object> errorDetails = new HashMap<>();
+            errorDetails.put("errorId", String.format("%016x", id));
+            errorDetails.put("message", "No exception provided.");
+            errorDetails.put("causes", new ArrayList<>());
+            return AtlasType.toJson(errorDetails);
+        }
+
+        // Prepare data for error message
+        Map<String, Object> errorDetails = new HashMap<>();
+        errorDetails.put("errorId", String.format("%016x", id));
+        errorDetails.put("message", "There was an error processing your request.");
+
+        // Create a list of causes
+        List<Map<String, String>> causes = new ArrayList<>();
+        List<Throwable> visited = new ArrayList<>();
+        Throwable currentException = exception;
+
+        while (currentException != null) {
+            if (visited.contains(currentException)) {
+                // If circular reference detected, add special entry
+                Map<String, String> circularCause = new HashMap<>();
+                circularCause.put("errorType", "CircularReferenceDetected");
+                circularCause.put("errorMessage", "A circular reference was detected in the exception chain.");
+                circularCause.put("location", "Unavailable");
+                causes.add(circularCause);
+                break;
+            }
+            visited.add(currentException);
+            causes.add(formatCause(currentException));
+            currentException = currentException.getCause();
+        }
+
+        errorDetails.put("causes", causes);
+
+        return AtlasType.toJson(errorDetails);
+    }
+
+    // Helper method to format a single exception cause
+    private static Map<String, String> formatCause(Throwable exception) {
+        Map<String, String> cause = new HashMap<>();
+
+        // Extract location details from the first stack trace element
+        StackTraceElement[] stackTrace = exception.getStackTrace();
+        String location = "Unavailable";
+        if (stackTrace != null && stackTrace.length > 0) {
+            StackTraceElement element = stackTrace[0];
+            location = String.format("%s.%s (%s:%d)",
+                    element.getClassName(),
+                    element.getMethodName(),
+                    element.getFileName(),
+                    element.getLineNumber());
+        }
+
+        // Populate the cause map
+        cause.put("errorType", exception.getClass().getName());
+        cause.put("errorMessage", exception.getMessage() != null ? exception.getMessage() : "No additional information provided");
+        cause.put("location", location);
+
+        return cause;
     }
 
     protected static void logException(long id, Exception exception) {
@@ -36,5 +101,4 @@ protected static void logException(long id, Exception exception) {
     protected static String formatLogMessage(long id, Throwable exception) {
         return String.format("Error handling a request: %016x", id);
     }
-
 }