From 70b6e9e8b414c9ae2159f7b87e245bc3ff0e0a88 Mon Sep 17 00:00:00 2001
From: Lukas Krecan <lukas@krecan.net>
Date: Wed, 26 Jun 2024 19:31:07 +0200
Subject: [PATCH] Lazy initialization of JsonMap

---
 .../core/internal/ComparisonMatrix.java       |  7 +++--
 .../jsonunit/core/internal/Node.java          | 28 +++++++++++++------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java
index 6f5c0c7f8..1c0a9cc01 100644
--- a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java
+++ b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java
@@ -86,8 +86,9 @@ ComparisonMatrix compare() {
                 List<Integer> matches = getEqualValues(i);
                 if (matches.size() == 1) {
                     recordMatch(i, matches.get(0));
-                } else if (matches.size() > 0) {
-                    // we have more matches, since comparison does not have to be transitive ([1, 2] == [2] == [2, 3]), we have to check all the possibilities
+                } else if (!matches.isEmpty()) {
+                    // we have more matches, since comparison does not have to be transitive ([1, 2] == [2] == [2, 3]),
+                    // we have to check all the possibilities
                     for (int match : matches) {
                         ComparisonMatrix copy = copy(i + 1);
                         copy.recordMatch(i, match);
@@ -114,7 +115,7 @@ private void doSimpleMatching() {
         for (int i = 0; i < equalElements.size(); i++) {
             if (!alreadyMatched.get(i)) {
                 List<Integer> equalTo = equalElements.get(i);
-                if (equalTo.size() > 0) {
+                if (!equalTo.isEmpty()) {
                     List<Integer> equivalentElements = getEquivalentElements(equalTo);
 
                     // We have the same set matching as is equivalent, we can remove them all
diff --git a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Node.java b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Node.java
index a400b9b55..95a641794 100644
--- a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Node.java
+++ b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Node.java
@@ -15,11 +15,19 @@
  */
 package net.javacrumbs.jsonunit.core.internal;
 
+
+import org.jetbrains.annotations.NotNull;
 import java.math.BigDecimal;
+import java.util.AbstractMap;
 import java.util.Collections;
 import java.util.Iterator;
-import java.util.LinkedHashMap;
 import java.util.LinkedList;
+import java.util.Set;
+import java.util.Spliterators;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+import static net.javacrumbs.jsonunit.core.internal.JsonUtils.prettyPrint;
 
 import static net.javacrumbs.jsonunit.core.internal.JsonUtils.prettyPrint;
 
@@ -33,7 +41,7 @@ enum NodeType implements ValueExtractor {
         OBJECT("object") {
             @Override
             public Object getValue(Node node) {
-                // custom conversion to map. We want be consistent and native mapping may have different rules for
+                // custom conversion to map. We want to be consistent and native mapping may have different rules for
                 // serializing numbers, dates etc.
                 return new JsonMap(node);
             }
@@ -214,16 +222,20 @@ interface ValueExtractor {
         Object getValue(Node node);
     }
 
-    class JsonMap extends LinkedHashMap<String, Object> implements NodeWrapper {
+    class JsonMap extends AbstractMap<String, Object> implements NodeWrapper {
         private final Node wrappedNode;
 
         JsonMap(Node node) {
             wrappedNode = node;
-            Iterator<KeyValue> fields = node.fields();
-            while (fields.hasNext()) {
-                KeyValue keyValue = fields.next();
-                put(keyValue.getKey(), keyValue.getValue().getValue());
-            }
+        }
+
+        @NotNull
+        @Override
+        public Set<Entry<String, Object>> entrySet() {
+            Iterator<KeyValue> fields = wrappedNode.fields();
+            return StreamSupport.stream(Spliterators.spliteratorUnknownSize(fields, 0), false)
+                .map(keyValue -> new SimpleEntry<>(keyValue.getKey(), keyValue.getValue().getValue()))
+                .collect(Collectors.toSet());
         }
 
         @Override