Use Objects.equals() now that it is available (Java 8) (#303)

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -14,6 +14,8 @@ NOTE: Jackson 3.x components rely on 2.x annotations; there are no separate
 === Releases ===
 ------------------------------------------------------------------------
 
+- Use `Objects.equals()` for comparison (with Java 8 baseline)
+
 2.20-rc1 (04-Aug-2025)
 
 #293: Improve duplicate Id with different associated object error message

src/main/java/com/fasterxml/jackson/annotation/JacksonInject.java

@@ -4,6 +4,7 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
+import java.util.Objects;
 
 /**
  * Jackson-specific annotation used for indicating that value of
@@ -226,12 +227,9 @@ public boolean equals(Object o) {
             if (o.getClass() == getClass()) {
                 Value other = (Value) o;
 
-                return (_id == null && other._id == null
-                        || _id != null && _id.equals(other._id))
-                        && (_useInput == null && other._useInput == null
-                        || _useInput != null && _useInput.equals(other._useInput))
-                        && (_optional == null && other._optional == null
-                        || _optional != null && _optional.equals(other._optional));
+                return Objects.equals(_id, other._id)
+                        && Objects.equals(_useInput, other._useInput)
+                        && Objects.equals(_optional, other._optional);
             }
             return false;
         }
@@ -243,7 +241,7 @@ public boolean equals(Object o) {
          */
 
         private static boolean _empty(Object id, Boolean useInput, Boolean optional) {
-            return (id == null) && (useInput == null) && optional == null;
+            return (id == null) && (useInput == null) && (optional == null);
         }
     }
 }

src/main/java/com/fasterxml/jackson/annotation/JsonFormat.java

@@ -2,6 +2,7 @@
 
 import java.lang.annotation.*;
 import java.util.Locale;
+import java.util.Objects;
 import java.util.TimeZone;
 
 /**
@@ -900,22 +901,11 @@ public boolean equals(Object o) {
                     || !_features.equals(other._features)) {
                 return false;
             }
-            return _equal(_lenient, other._lenient)
-                    && _equal(_timezoneStr, other._timezoneStr)
-                    && _equal(_pattern, other._pattern)
-                    && _equal(_timezone, other._timezone)
-                    && _equal(_locale, other._locale);
-        }
-
-        private static <T> boolean _equal(T value1, T value2)
-        {
-            if (value1 == null) {
-                return (value2 == null);
-            }
-            if (value2 == null) {
-                return false;
-            }
-            return value1.equals(value2);
+            return Objects.equals(_lenient, other._lenient)
+                    && Objects.equals(_timezoneStr, other._timezoneStr)
+                    && Objects.equals(_pattern, other._pattern)
+                    && Objects.equals(_timezone, other._timezone)
+                    && Objects.equals(_locale, other._locale);
         }
     }
 }

src/main/java/com/fasterxml/jackson/annotation/JsonIncludeProperties.java

@@ -139,14 +139,8 @@ public int hashCode() {
         public boolean equals(Object o) {
             if (o == this) return true;
             if (o == null) return false;
-            return (o.getClass() == getClass()) && _equals(_included, ((Value) o)._included);
-        }
-
-        private static boolean _equals(Set<String> a, Set<String> b)
-        {
-            return a == null ? (b == null)
-                    // keep this last just because it can be expensive
-                    : a.equals(b);
+            return (o.getClass() == getClass())
+                    && Objects.equals(_included, ((Value) o)._included);
         }
 
         private static Set<String> _asSet(String[] v)

src/main/java/com/fasterxml/jackson/annotation/JsonTypeInfo.java

@@ -4,6 +4,7 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
+import java.util.Objects;
 
 /**
  * Annotation used for configuring details of if and how type information is
@@ -536,20 +537,9 @@ private static boolean _equals(Value a, Value b)
                     && (a._inclusionType == b._inclusionType)
                     && (a._defaultImpl == b._defaultImpl)
                     && (a._idVisible == b._idVisible)
-                    && _equal(a._propertyName, b._propertyName)
-                    && _equal(a._requireTypeIdForSubtypes, b._requireTypeIdForSubtypes)
+                    && Objects.equals(a._propertyName, b._propertyName)
+                    && Objects.equals(a._requireTypeIdForSubtypes, b._requireTypeIdForSubtypes)
             ;
         }
-
-        private static <T> boolean _equal(T value1, T value2)
-        {
-            if (value1 == null) {
-                return (value2 == null);
-            }
-            if (value2 == null) {
-                return false;
-            }
-            return value1.equals(value2);
-        }
     }
 }