Merge branch 'master' of ssh://github.com/ExpediaGroup/bull into develop

Author: fborriello

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 All notable changes to this project will be documented in this file.
 
+### [3.0.4] 2026.04.27
+* Replaces 12-branch if-else chains in `ConversionProcessorFactory` and `ConversionAnalyzer` with switch expressions and cached processor singletons, eliminating per-call object allocation in the type conversion hot path
+* Removes `AtomicReference` allocation in `ReflectionUtils.getRealTarget` using instanceof pattern matching; eliminates redundant `isAnnotationPresent` check before `getAnnotation`
+* Replaces stream-based type checks in `ClassUtils.isSpecialType` and `isCustomSpecialType` with plain loops to avoid lambda allocation on frequently-called paths
+* Replaces `LinkedList` with `ArrayList` in `ClassUtils.getMethods` for better cache locality; replaces intermediate `collect(toList())` with `toList()` throughout
+* Replaces inner stream+lambda in `AbstractTransformer.withFieldMapping` and `withFieldTransformer` with plain for-each loops
+* Replaces `keySet().stream().collect(toMap(...))` in `MapPopulator` with an `entrySet()` imperative loop and pre-sized `HashMap`; applies instanceof pattern matching to eliminate `getClass().equals()` calls
+* Adds JMH microbenchmarks covering simple-bean, complex-bean, map, and type-conversion transformation paths
+
 ### [3.0.3] 2026.04.01
 * Refactors `TransformerImpl` to use direct field access via reflection utilities instead of string-literal field names, improving maintainability and robustness
 * Eliminates redundant `ThreadLocal` initialisation by reusing the existing `rootSourceStack` instance

benchmark.sh

@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+# Builds the JMH benchmark fat jar and runs it, then prints a formatted
+# transformation-time summary.
+# Any arguments are forwarded to JMH, e.g.:
+#   ./benchmark.sh                          # full run (~10-15 min)
+#   ./benchmark.sh -f 1 -wi 2 -i 3         # quick smoke run (~2 min)
+#   ./benchmark.sh mutableSimpleBean        # single benchmark
+#   ./benchmark.sh -rf json -rff out.json   # write results to JSON
+
+set -euo pipefail
+
+MODULES="bull-common,bull-converter,bull-bean-transformer,bull-benchmark"
+JAR="bull-benchmark/target/benchmarks.jar"
+MVN="./mvnw"
+
+if [[ "$(uname -s)" == MINGW* || "$(uname -s)" == CYGWIN* ]]; then
+    MVN="./mvnw.cmd"
+fi
+
+echo "==> Building benchmark jar..."
+BUILD_LOG=$(mktemp)
+trap 'rm -f "$TMPOUT" "$BUILD_LOG"' EXIT
+if ! "$MVN" package -pl "$MODULES" -DskipTests -Djacoco.skip=true -q >"$BUILD_LOG" 2>&1; then
+    cat "$BUILD_LOG"
+    exit 1
+fi
+
+TMPOUT=$(mktemp)
+
+echo "==> Running benchmarks..."
+java -jar "$JAR" "$@" 2>&1 \
+    | grep -v \
+        -e "^NOTE:" \
+        -e "^WARNING:" \
+        -e "^Processing [0-9]" \
+        -e "^Writing out" \
+    | tee "$TMPOUT"
+
+# -----------------------------------------------------------------------
+# Pretty-print a transformation-time summary from the JMH result lines.
+# Scores are in µs/op; we convert to ms for readability.
+# Result lines look like either of:
+#   TransformerBenchmark.mutableSimpleBean  avgt   2   0.536          us/op
+#   TransformerBenchmark.mutableSimpleBean  avgt  20   0.536 ± 0.012  us/op
+# -----------------------------------------------------------------------
+echo ""
+echo "==> Transformation times summary (ms/op):"
+echo ""
+
+awk '
+function us_to_ms(v,    r) {
+    r = v / 1000
+    # print with enough decimals to show non-zero values even for fast paths
+    return sprintf("%.6f", r)
+}
+/^TransformerBenchmark\./ {
+    split($1, parts, ".")
+    name  = parts[2]
+    score = $4
+    if ($5 == "±") { error = "± " us_to_ms($6); unit = $7 }
+    else            { error = "";                unit = $5 }
+    scores[name]  = us_to_ms(score)
+    errors[name]  = error
+    # classify into bean transformations vs type conversions
+    if (name ~ /typeConversion/) {
+        conv[length(conv)+1] = name
+    } else {
+        beans[length(beans)+1] = name
+    }
+}
+END {
+    fmt = "  %-44s  %12s  %-16s\n"
+    sep = "  " sprintf("%-44s", "--------------------------------------------") \
+          "  " sprintf("%-12s", "------------") \
+          "  " sprintf("%-16s", "----------------")
+
+    print "  Bean transformations:"
+    printf fmt, "  Benchmark", "Time (ms/op)", "Error (ms/op)"
+    print sep
+    for (i = 1; i <= length(beans); i++) {
+        n = beans[i]
+        printf fmt, "  " n, scores[n], errors[n]
+    }
+
+    print ""
+    print "  Type conversions:"
+    printf fmt, "  Benchmark", "Time (ms/op)", "Error (ms/op)"
+    print sep
+    for (i = 1; i <= length(conv); i++) {
+        n = conv[i]
+        printf fmt, "  " n, scores[n], errors[n]
+    }
+}
+' "$TMPOUT"

bull-bean-transformer/pom.xml

@@ -8,7 +8,7 @@
     <parent>
         <groupId>com.expediagroup.beans</groupId>
         <artifactId>bean-utils-library-parent</artifactId>
-        <version>3.0.4-SNAPSHOT</version>
+        <version>3.0.5-SNAPSHOT</version>
     </parent>
 
     <dependencies>

bull-bean-transformer/src/main/java/com/expediagroup/beans/populator/MapPopulator.java

@@ -15,9 +15,8 @@
  */
 package com.expediagroup.beans.populator;
 
-import static java.util.stream.Collectors.toMap;
-
 import java.lang.reflect.Field;
+import java.util.HashMap;
 import java.util.Map;
 
 import com.expediagroup.beans.transformer.BeanTransformer;
@@ -58,16 +57,14 @@ class MapPopulator extends Populator<Map<?, ?>> {
         final MapElemType elemType = mapType.getElemType();
         final boolean keyIsPrimitive = isPrimitive(keyType);
         final boolean elemIsPrimitive = isPrimitive(elemType);
-        Map<?, ?> populatedObject;
         if (keyIsPrimitive && elemIsPrimitive) {
-            populatedObject = fieldValue;
-        } else {
-            populatedObject = fieldValue.keySet()
-                    .stream()
-//                    .parallelStream()
-                    .collect(toMap(
-                        key -> getElemValue(keyType, keyIsPrimitive, key),
-                        key -> getElemValue(elemType, elemIsPrimitive, fieldValue.get(key))));
+            return fieldValue;
+        }
+        Map<Object, Object> populatedObject = new HashMap<>(fieldValue.size());
+        for (Map.Entry<?, ?> entry : fieldValue.entrySet()) {
+            populatedObject.put(
+                    getElemValue(keyType, keyIsPrimitive, entry.getKey()),
+                    getElemValue(elemType, elemIsPrimitive, entry.getValue()));
         }
         return populatedObject;
     }
@@ -78,7 +75,7 @@ class MapPopulator extends Populator<Map<?, ?>> {
      * @return true if it's primitive, false otherwise
      */
     private boolean isPrimitive(final MapElemType mapElemType) {
-        return mapElemType.getClass().equals(ItemType.class) && classUtils.isPrimitiveOrSpecialType(((ItemType) mapElemType).getObjectClass());
+        return mapElemType instanceof ItemType itemType && classUtils.isPrimitiveOrSpecialType(itemType.getObjectClass());
     }
 
     /**
@@ -91,16 +88,12 @@ private boolean isPrimitive(final MapElemType mapElemType) {
      */
     @SuppressWarnings("unchecked")
     private <T> T getElemValue(final MapElemType mapElemType, final boolean elemIsPrimitiveType, final T value) {
-        final T elemValue;
         if (elemIsPrimitiveType || classUtils.isPrimitiveOrSpecialType(value.getClass())) {
-            elemValue = value;
-        } else {
-            if (mapElemType.getClass().equals(ItemType.class)) {
-                elemValue = (T) transform(value, ((ItemType) mapElemType).getObjectClass(), ((ItemType) mapElemType).getGenericClass());
-            } else {
-                elemValue = (T) getPopulatedObject((Map) value, (MapType) mapElemType);
-            }
+            return value;
+        }
+        if (mapElemType instanceof ItemType itemType) {
+            return (T) transform(value, itemType.getObjectClass(), itemType.getGenericClass());
         }
-        return elemValue;
+        return (T) getPopulatedObject((Map<?, ?>) value, (MapType) mapElemType);
     }
 }

bull-bean-transformer/src/main/java/com/expediagroup/beans/transformer/AbstractBeanTransformer.java

@@ -15,8 +15,6 @@
  */
 package com.expediagroup.beans.transformer;
 
-import static java.util.Arrays.asList;
-
 import static com.expediagroup.transformer.validator.Validator.notNull;
 
 import com.expediagroup.beans.conversion.analyzer.ConversionAnalyzer;
@@ -150,8 +148,8 @@ public final <T, K> void transform(final T sourceObj, final K targetObject) {
      */
     @Override
     public BeanTransformer skipTransformationForField(final String... fieldName) {
-        if (fieldName.length != 0) {
-            settings.getFieldsToSkip().addAll(asList(fieldName));
+        for (String field : fieldName) {
+            settings.getFieldsToSkip().add(field);
         }
         return this;
     }