Add Signature Processor bug fix

ClassCastException

Author: ronshay

sawmill-core/src/main/java/io/logz/sawmill/processors/AddSignatureProcessor.java

@@ -78,7 +78,7 @@ private Set<String> getFieldsValues(Doc doc) {
         return includeValueFields.stream()
                 .filter(doc::hasField)
                 .map(fieldName -> {
-                    String value = doc.getField(fieldName);
+                    String value = doc.getField(fieldName).toString();
                     return "value_" + fieldName + "_" + value;
                 }).collect(Collectors.toSet());
     }

sawmill-core/src/test/java/io/logz/sawmill/processors/AddSignatureProcessorTest.java

@@ -349,7 +349,7 @@ private Set<String> getFieldsValues(Doc doc, Set<String> includeValueFields) {
         return includeValueFields.stream()
                 .filter(doc::hasField)
                 .map(fieldName -> {
-                    String value = doc.getField(fieldName);
+                    String value = doc.getField(fieldName).toString();
                     return "value_" + fieldName + "_" + value;
                 }).collect(Collectors.toSet());
     }