8267110: Update java.util to use instanceof pattern variable

Reviewed-by: lancea, naoto

src/java.base/share/classes/java/util/AbstractMap.java

@@ -476,9 +476,8 @@ public abstract class AbstractMap<K,V> implements Map<K,V> {
         if (o == this)
             return true;
 
-        if (!(o instanceof Map))
+        if (!(o instanceof Map<?, ?> m))
             return false;
-        Map<?,?> m = (Map<?,?>) o;
         if (m.size() != size())
             return false;
 
@@ -688,10 +687,9 @@ public abstract class AbstractMap<K,V> implements Map<K,V> {
          * @see    #hashCode
          */
         public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> e
-                return false;
+                    && eq(key, e.getKey())
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                    && eq(value, e.getValue());
-            return eq(key, e.getKey()) && eq(value, e.getValue());
         }
 
         /**
@@ -822,10 +820,9 @@ public abstract class AbstractMap<K,V> implements Map<K,V> {
          * @see    #hashCode
          */
         public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> e
-                return false;
+                    && eq(key, e.getKey())
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                    && eq(value, e.getValue());
-            return eq(key, e.getKey()) && eq(value, e.getValue());
         }
 
         /**

src/java.base/share/classes/java/util/BitSet.java

@@ -1066,13 +1066,11 @@ public class BitSet implements Cloneable, java.io.Serializable {
      * @see    #size()
      */
     public boolean equals(Object obj) {
-        if (!(obj instanceof BitSet))
+        if (!(obj instanceof BitSet set))
             return false;
         if (this == obj)
             return true;
 
-        BitSet set = (BitSet) obj;
-
         checkInvariants();
         set.checkInvariants();
 

src/java.base/share/classes/java/util/Collections.java

@@ -1775,12 +1775,9 @@ public class Collections {
                 if (o == this)
                     return true;
 
-                if (!(o instanceof Set))
+                return o instanceof Set<?> s
-                    return false;
+                        && s.size() == c.size()
-                Set<?> s = (Set<?>) o;
+                        && containsAll(s); // Invokes safe containsAll() above
-                if (s.size() != c.size())
-                    return false;
-                return containsAll(s); // Invokes safe containsAll() above
             }
 
             /**
@@ -1805,11 +1802,9 @@ public class Collections {
                 public boolean equals(Object o) {
                     if (this == o)
                         return true;
-                    if (!(o instanceof Map.Entry))
+                    return o instanceof Map.Entry<?, ?> t
-                        return false;
+                            && eq(e.getKey(),   t.getKey())
-                    Map.Entry<?,?> t = (Map.Entry<?,?>)o;
+                            && eq(e.getValue(), t.getValue());
-                    return eq(e.getKey(),   t.getKey()) &&
-                           eq(e.getValue(), t.getValue());
                 }
                 public String toString() {return e.toString();}
             }
@@ -3933,11 +3928,8 @@ public class Collections {
              * setValue method.
              */
             public boolean contains(Object o) {
-                if (!(o instanceof Map.Entry))
+                return o instanceof Map.Entry<?, ?> e
-                    return false;
+                        && s.contains((e instanceof CheckedEntry) ? e : checkedEntry(e, valueType));
-                Map.Entry<?,?> e = (Map.Entry<?,?>) o;
-                return s.contains(
-                    (e instanceof CheckedEntry) ? e : checkedEntry(e, valueType));
             }
 
             /**
@@ -3981,11 +3973,9 @@ public class Collections {
             public boolean equals(Object o) {
                 if (o == this)
                     return true;
-                if (!(o instanceof Set))
+                return o instanceof Set<?> that
-                    return false;
+                        && that.size() == s.size()
-                Set<?> that = (Set<?>) o;
+                        && containsAll(that); // Invokes safe containsAll() above
-                return that.size() == s.size()
-                    && containsAll(that); // Invokes safe containsAll() above
             }
 
             static <K,V,T> CheckedEntry<K,V,T> checkedEntry(Map.Entry<K,V> e,
@@ -5251,8 +5241,7 @@ public class Collections {
         public boolean equals(Object o) {
             if (o == this)
                 return true;
-            if (o instanceof CopiesList) {
+            if (o instanceof CopiesList<?> other) {
-                CopiesList<?> other = (CopiesList<?>) o;
                 return n == other.n && (n == 0 || eq(element, other.element));
             }
             if (!(o instanceof List))

src/java.base/share/classes/java/util/EnumMap.java

@@ -328,8 +328,7 @@ public class EnumMap<K extends Enum<K>, V> extends AbstractMap<K, V>
      *     one or more keys in the specified map are null
      */
     public void putAll(Map<? extends K, ? extends V> m) {
-        if (m instanceof EnumMap) {
+        if (m instanceof EnumMap<?, ?> em) {
-            EnumMap<?, ?> em = (EnumMap<?, ?>)m;
             if (em.keyType != keyType) {
                 if (em.isEmpty())
                     return;
@@ -473,16 +472,12 @@ public class EnumMap<K extends Enum<K>, V> extends AbstractMap<K, V>
         }
 
         public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> entry
-                return false;
+                    && containsMapping(entry.getKey(), entry.getValue());
-            Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
-            return containsMapping(entry.getKey(), entry.getValue());
         }
         public boolean remove(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> entry
-                return false;
+                    && removeMapping(entry.getKey(), entry.getValue());
-            Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
-            return removeMapping(entry.getKey(), entry.getValue());
         }
         public int size() {
             return size;
@@ -606,10 +601,9 @@ public class EnumMap<K extends Enum<K>, V> extends AbstractMap<K, V>
                 if (index < 0)
                     return o == this;
 
-                if (!(o instanceof Map.Entry))
+                if (!(o instanceof Map.Entry<?, ?> e))
                     return false;
 
-                Map.Entry<?,?> e = (Map.Entry<?,?>)o;
                 V ourValue = unmaskNull(vals[index]);
                 Object hisValue = e.getValue();
                 return (e.getKey() == keyUniverse[index] &&
@@ -655,10 +649,9 @@ public class EnumMap<K extends Enum<K>, V> extends AbstractMap<K, V>
             return true;
         if (o instanceof EnumMap)
             return equals((EnumMap<?,?>)o);
-        if (!(o instanceof Map))
+        if (!(o instanceof Map<?, ?> m))
             return false;
 
-        Map<?,?> m = (Map<?,?>)o;
         if (size != m.size())
             return false;
 

src/java.base/share/classes/java/util/HashMap.java

@@ -307,13 +307,10 @@ public class HashMap<K,V> extends AbstractMap<K,V>
         public final boolean equals(Object o) {
             if (o == this)
                 return true;
-            if (o instanceof Map.Entry) {
+
-                Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+            return o instanceof Map.Entry<?, ?> e
-                if (Objects.equals(key, e.getKey()) &&
+                    && Objects.equals(key, e.getKey())
-                    Objects.equals(value, e.getValue()))
+                    && Objects.equals(value, e.getValue());
-                    return true;
-            }
-            return false;
         }
     }
 
@@ -1100,16 +1097,14 @@ public class HashMap<K,V> extends AbstractMap<K,V>
             return new EntryIterator();
         }
         public final boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> e))
                 return false;
-            Map.Entry<?,?> e = (Map.Entry<?,?>) o;
             Object key = e.getKey();
             Node<K,V> candidate = getNode(key);
             return candidate != null && candidate.equals(e);
         }
         public final boolean remove(Object o) {
-            if (o instanceof Map.Entry) {
+            if (o instanceof Map.Entry<?, ?> e) {
-                Map.Entry<?,?> e = (Map.Entry<?,?>) o;
                 Object key = e.getKey();
                 Object value = e.getValue();
                 return removeNode(hash(key), key, value, true, true) != null;

src/java.base/share/classes/java/util/Hashtable.java

@@ -714,9 +714,8 @@ public class Hashtable<K,V>
         }
 
         public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> entry))
                 return false;
-            Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
             Object key = entry.getKey();
             Entry<?,?>[] tab = table;
             int hash = key.hashCode();
@@ -729,9 +728,8 @@ public class Hashtable<K,V>
         }
 
         public boolean remove(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> entry))
                 return false;
-            Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
             Object key = entry.getKey();
             Entry<?,?>[] tab = table;
             int hash = key.hashCode();
@@ -816,9 +814,8 @@ public class Hashtable<K,V>
         if (o == this)
             return true;
 
-        if (!(o instanceof Map))
+        if (!(o instanceof Map<?, ?> t))
             return false;
-        Map<?,?> t = (Map<?,?>) o;
         if (t.size() != size())
             return false;
 
@@ -1393,9 +1390,8 @@ public class Hashtable<K,V>
         }
 
         public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> e))
                 return false;
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
 
             return (key==null ? e.getKey()==null : key.equals(e.getKey())) &&
                (value==null ? e.getValue()==null : value.equals(e.getValue()));

src/java.base/share/classes/java/util/IdentityHashMap.java

@@ -642,8 +642,7 @@ public class IdentityHashMap<K,V>
     public boolean equals(Object o) {
         if (o == this) {
             return true;
-        } else if (o instanceof IdentityHashMap) {
+        } else if (o instanceof IdentityHashMap<?, ?> m) {
-            IdentityHashMap<?,?> m = (IdentityHashMap<?,?>) o;
             if (m.size() != size)
                 return false;
 
@@ -654,8 +653,7 @@ public class IdentityHashMap<K,V>
                     return false;
             }
             return true;
-        } else if (o instanceof Map) {
+        } else if (o instanceof Map<?, ?> m) {
-            Map<?,?> m = (Map<?,?>)o;
             return entrySet().equals(m.entrySet());
         } else {
             return false;  // o is not a Map
@@ -888,11 +886,9 @@ public class IdentityHashMap<K,V>
                 if (index < 0)
                     return super.equals(o);
 
-                if (!(o instanceof Map.Entry))
+                return o instanceof Map.Entry<?, ?> e
-                    return false;
+                        && e.getKey() == unmaskNull(traversalTable[index])
-                Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                        && e.getValue() == traversalTable[index+1];
-                return (e.getKey() == unmaskNull(traversalTable[index]) &&
-                       e.getValue() == traversalTable[index+1]);
             }
 
             public int hashCode() {
@@ -1189,16 +1185,12 @@ public class IdentityHashMap<K,V>
             return new EntryIterator();
         }
         public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Entry<?, ?> entry
-                return false;
+                    && containsMapping(entry.getKey(), entry.getValue());
-            Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
-            return containsMapping(entry.getKey(), entry.getValue());
         }
         public boolean remove(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Entry<?, ?> entry
-                return false;
+                    && removeMapping(entry.getKey(), entry.getValue());
-            Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
-            return removeMapping(entry.getKey(), entry.getValue());
         }
         public int size() {
             return size;

src/java.base/share/classes/java/util/JumboEnumSet.java

@@ -248,10 +248,9 @@ class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean containsAll(Collection<?> c) {
-        if (!(c instanceof JumboEnumSet))
+        if (!(c instanceof JumboEnumSet<?> es))
             return super.containsAll(c);
 
-        JumboEnumSet<?> es = (JumboEnumSet<?>)c;
         if (es.elementType != elementType)
             return es.isEmpty();
 
@@ -270,10 +269,9 @@ class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
      *     its elements are null
      */
     public boolean addAll(Collection<? extends E> c) {
-        if (!(c instanceof JumboEnumSet))
+        if (!(c instanceof JumboEnumSet<?> es))
             return super.addAll(c);
 
-        JumboEnumSet<?> es = (JumboEnumSet<?>)c;
         if (es.elementType != elementType) {
             if (es.isEmpty())
                 return false;
@@ -296,10 +294,9 @@ class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean removeAll(Collection<?> c) {
-        if (!(c instanceof JumboEnumSet))
+        if (!(c instanceof JumboEnumSet<?> es))
             return super.removeAll(c);
 
-        JumboEnumSet<?> es = (JumboEnumSet<?>)c;
         if (es.elementType != elementType)
             return false;
 
@@ -317,10 +314,9 @@ class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean retainAll(Collection<?> c) {
-        if (!(c instanceof JumboEnumSet))
+        if (!(c instanceof JumboEnumSet<?> es))
             return super.retainAll(c);
 
-        JumboEnumSet<?> es = (JumboEnumSet<?>)c;
         if (es.elementType != elementType) {
             boolean changed = (size != 0);
             clear();
@@ -350,10 +346,9 @@ class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @return {@code true} if the specified object is equal to this set
      */
     public boolean equals(Object o) {
-        if (!(o instanceof JumboEnumSet))
+        if (!(o instanceof JumboEnumSet<?> es))
             return super.equals(o);
 
-        JumboEnumSet<?> es = (JumboEnumSet<?>)o;
         if (es.elementType != elementType)
             return size == 0 && es.size == 0;
 

src/java.base/share/classes/java/util/KeyValueHolder.java

@@ -101,10 +101,9 @@ final class KeyValueHolder<K,V> implements Map.Entry<K,V> {
      */
     @Override
     public boolean equals(Object o) {
-        if (!(o instanceof Map.Entry))
+        return o instanceof Map.Entry<?, ?> e
-            return false;
+                && key.equals(e.getKey())
-        Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                && value.equals(e.getValue());
-        return key.equals(e.getKey()) && value.equals(e.getValue());
     }
 
     /**

src/java.base/share/classes/java/util/LinkedHashMap.java

@@ -681,16 +681,14 @@ public class LinkedHashMap<K,V>
             return new LinkedEntryIterator();
         }
         public final boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> e))
                 return false;
-            Map.Entry<?,?> e = (Map.Entry<?,?>) o;
             Object key = e.getKey();
             Node<K,V> candidate = getNode(key);
             return candidate != null && candidate.equals(e);
         }
         public final boolean remove(Object o) {
-            if (o instanceof Map.Entry) {
+            if (o instanceof Map.Entry<?, ?> e) {
-                Map.Entry<?,?> e = (Map.Entry<?,?>) o;
                 Object key = e.getKey();
                 Object value = e.getValue();
                 return removeNode(hash(key), key, value, true, true) != null;

src/java.base/share/classes/java/util/Locale.java

@@ -885,10 +885,9 @@ public final class Locale implements Cloneable, Serializable {
             if (this == obj) {
                 return true;
             }
-            if (!(obj instanceof LocaleKey)) {
+            if (!(obj instanceof LocaleKey other)) {
                 return false;
             }
-            LocaleKey other = (LocaleKey)obj;
             if (hash != other.hash || !base.equals(other.base)) {
                 return false;
             }
@@ -3341,12 +3340,9 @@ public final class Locale implements Cloneable, Serializable {
             if (this == obj) {
                 return true;
             }
-            if (!(obj instanceof LanguageRange)) {
+            return obj instanceof LanguageRange other
-                return false;
+                    && range.equals(other.range)
-            }
+                    && weight == other.weight;
-            LanguageRange other = (LanguageRange)obj;
-            return range.equals(other.range)
-                   && weight == other.weight;
         }
 
         /**

src/java.base/share/classes/java/util/Optional.java

@@ -423,12 +423,8 @@ public final class Optional<T> {
             return true;
         }
 
-        if (!(obj instanceof Optional)) {
+        return obj instanceof Optional<?> other
-            return false;
+                && Objects.equals(value, other.value);
-        }
-
-        Optional<?> other = (Optional<?>) obj;
-        return Objects.equals(value, other.value);
     }
 
     /**

src/java.base/share/classes/java/util/OptionalDouble.java

@@ -295,14 +295,10 @@ public final class OptionalDouble {
             return true;
         }
 
-        if (!(obj instanceof OptionalDouble)) {
+        return obj instanceof OptionalDouble other
-            return false;
+                && (isPresent && other.isPresent
-        }
+                ? Double.compare(value, other.value) == 0
-
+                : isPresent == other.isPresent);
-        OptionalDouble other = (OptionalDouble) obj;
-        return (isPresent && other.isPresent)
-               ? Double.compare(value, other.value) == 0
-               : isPresent == other.isPresent;
     }
 
     /**

src/java.base/share/classes/java/util/OptionalInt.java

@@ -293,14 +293,10 @@ public final class OptionalInt {
             return true;
         }
 
-        if (!(obj instanceof OptionalInt)) {
+        return obj instanceof OptionalInt other
-            return false;
+                && (isPresent && other.isPresent
-        }
-
-        OptionalInt other = (OptionalInt) obj;
-        return (isPresent && other.isPresent)
                 ? value == other.value
-                : isPresent == other.isPresent;
+                : isPresent == other.isPresent);
     }
 
     /**

src/java.base/share/classes/java/util/OptionalLong.java

@@ -293,14 +293,10 @@ public final class OptionalLong {
             return true;
         }
 
-        if (!(obj instanceof OptionalLong)) {
+        return obj instanceof OptionalLong other
-            return false;
+                && (isPresent && other.isPresent
-        }
-
-        OptionalLong other = (OptionalLong) obj;
-        return (isPresent && other.isPresent)
                 ? value == other.value
-                : isPresent == other.isPresent;
+                : isPresent == other.isPresent);
     }
 
     /**

src/java.base/share/classes/java/util/PropertyPermission.java

@@ -187,15 +187,11 @@ public final class PropertyPermission extends BasicPermission {
      */
     @Override
     public boolean implies(Permission p) {
-        if (!(p instanceof PropertyPermission))
-            return false;
-
-        PropertyPermission that = (PropertyPermission) p;
-
         // we get the effective mask. i.e., the "and" of this and that.
         // They must be equal to that.mask for implies to return true.
-
+        return p instanceof PropertyPermission that
-        return ((this.mask & that.mask) == that.mask) && super.implies(that);
+                && ((this.mask & that.mask) == that.mask)
+                && super.implies(that);
     }
 
     /**
@@ -211,13 +207,9 @@ public final class PropertyPermission extends BasicPermission {
         if (obj == this)
             return true;
 
-        if (! (obj instanceof PropertyPermission))
+        return obj instanceof PropertyPermission that
-            return false;
+                && this.mask == that.mask
-
+                && this.getName().equals(that.getName());
-        PropertyPermission that = (PropertyPermission) obj;
-
-        return (this.mask == that.mask) &&
-            (this.getName().equals(that.getName()));
     }
 
     /**
@@ -471,14 +463,13 @@ final class PropertyPermissionCollection extends PermissionCollection
      */
     @Override
     public void add(Permission permission) {
-        if (! (permission instanceof PropertyPermission))
+        if (! (permission instanceof PropertyPermission pp))
             throw new IllegalArgumentException("invalid permission: "+
                                                permission);
         if (isReadOnly())
             throw new SecurityException(
                 "attempt to add a Permission to a readonly PermissionCollection");
 
-        PropertyPermission pp = (PropertyPermission) permission;
         String propName = pp.getName();
 
         // Add permission to map if it is absent, or replace with new
@@ -523,10 +514,9 @@ final class PropertyPermissionCollection extends PermissionCollection
      */
     @Override
     public boolean implies(Permission permission) {
-        if (! (permission instanceof PropertyPermission))
+        if (! (permission instanceof PropertyPermission pp))
             return false;
 
-        PropertyPermission pp = (PropertyPermission) permission;
         PropertyPermission x;
 
         int desired = pp.getMask();

src/java.base/share/classes/java/util/RegularEnumSet.java

@@ -196,10 +196,9 @@ class RegularEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean containsAll(Collection<?> c) {
-        if (!(c instanceof RegularEnumSet))
+        if (!(c instanceof RegularEnumSet<?> es))
             return super.containsAll(c);
 
-        RegularEnumSet<?> es = (RegularEnumSet<?>)c;
         if (es.elementType != elementType)
             return es.isEmpty();
 
@@ -215,10 +214,9 @@ class RegularEnumSet<E extends Enum<E>> extends EnumSet<E> {
      *     of its elements are null
      */
     public boolean addAll(Collection<? extends E> c) {
-        if (!(c instanceof RegularEnumSet))
+        if (!(c instanceof RegularEnumSet<?> es))
             return super.addAll(c);
 
-        RegularEnumSet<?> es = (RegularEnumSet<?>)c;
         if (es.elementType != elementType) {
             if (es.isEmpty())
                 return false;
@@ -241,10 +239,9 @@ class RegularEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean removeAll(Collection<?> c) {
-        if (!(c instanceof RegularEnumSet))
+        if (!(c instanceof RegularEnumSet<?> es))
             return super.removeAll(c);
 
-        RegularEnumSet<?> es = (RegularEnumSet<?>)c;
         if (es.elementType != elementType)
             return false;
 
@@ -262,10 +259,9 @@ class RegularEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @throws NullPointerException if the specified collection is null
      */
     public boolean retainAll(Collection<?> c) {
-        if (!(c instanceof RegularEnumSet))
+        if (!(c instanceof RegularEnumSet<?> es))
             return super.retainAll(c);
 
-        RegularEnumSet<?> es = (RegularEnumSet<?>)c;
         if (es.elementType != elementType) {
             boolean changed = (elements != 0);
             elements = 0;
@@ -294,10 +290,9 @@ class RegularEnumSet<E extends Enum<E>> extends EnumSet<E> {
      * @return {@code true} if the specified object is equal to this set
      */
     public boolean equals(Object o) {
-        if (!(o instanceof RegularEnumSet))
+        if (!(o instanceof RegularEnumSet<?> es))
             return super.equals(o);
 
-        RegularEnumSet<?> es = (RegularEnumSet<?>)o;
         if (es.elementType != elementType)
             return elements == 0 && es.elements == 0;
         return es.elements == elements;

src/java.base/share/classes/java/util/Scanner.java

@@ -2664,9 +2664,8 @@ public final class Scanner implements Iterator<String>, Closeable {
      */
     public BigInteger nextBigInteger(int radix) {
         // Check cached result
-        if ((typeCache != null) && (typeCache instanceof BigInteger)
+        if ((typeCache != null) && (typeCache instanceof BigInteger val)
             && this.radix == radix) {
-            BigInteger val = (BigInteger)typeCache;
             useTypeCache();
             return val;
         }
@@ -2730,8 +2729,7 @@ public final class Scanner implements Iterator<String>, Closeable {
      */
     public BigDecimal nextBigDecimal() {
         // Check cached result
-        if ((typeCache != null) && (typeCache instanceof BigDecimal)) {
+        if ((typeCache != null) && (typeCache instanceof BigDecimal val)) {
-            BigDecimal val = (BigDecimal)typeCache;
             useTypeCache();
             return val;
         }

src/java.base/share/classes/java/util/ServiceLoader.java

@@ -818,11 +818,8 @@ public final class ServiceLoader<S>
 
         @Override
         public boolean equals(Object ob) {
-            if (!(ob instanceof ProviderImpl))
+            return ob instanceof @SuppressWarnings("unchecked")ProviderImpl<?> that
-                return false;
+                    && this.service == that.service
-            @SuppressWarnings("unchecked")
-            ProviderImpl<?> that = (ProviderImpl<?>)ob;
-            return this.service == that.service
                     && this.type == that.type
                     && Objects.equals(this.acc, that.acc);
         }

src/java.base/share/classes/java/util/SimpleTimeZone.java

@@ -878,19 +878,14 @@ public class SimpleTimeZone extends TimeZone {
      * @return     True if the given {@code obj} is the same as this
      *             {@code SimpleTimeZone} object; false otherwise.
      */
-    public boolean equals(Object obj)
+    public boolean equals(Object obj) {
-    {
         if (this == obj) {
             return true;
         }
-        if (!(obj instanceof SimpleTimeZone)) {
-            return false;
-        }
 
-        SimpleTimeZone that = (SimpleTimeZone) obj;
+        return obj instanceof SimpleTimeZone that
-
+                && getID().equals(that.getID())
-        return getID().equals(that.getID()) &&
+                && hasSameRules(that);
-            hasSameRules(that);
     }
 
     /**
@@ -904,28 +899,26 @@ public class SimpleTimeZone extends TimeZone {
         if (this == other) {
             return true;
         }
-        if (!(other instanceof SimpleTimeZone)) {
+        return other instanceof SimpleTimeZone that
-            return false;
+                && rawOffset == that.rawOffset
-        }
+                && useDaylight == that.useDaylight
-        SimpleTimeZone that = (SimpleTimeZone) other;
+                && (!useDaylight ||
-        return rawOffset == that.rawOffset &&
+                        // Only check rules if using DST
-            useDaylight == that.useDaylight &&
+                        (dstSavings == that.dstSavings
-            (!useDaylight
+                        && startMode == that.startMode
-             // Only check rules if using DST
+                        && startMonth == that.startMonth
-             || (dstSavings == that.dstSavings &&
+                        && startDay == that.startDay
-                 startMode == that.startMode &&
+                        && startDayOfWeek == that.startDayOfWeek
-                 startMonth == that.startMonth &&
+                        && startTime == that.startTime
-                 startDay == that.startDay &&
+                        && startTimeMode == that.startTimeMode
-                 startDayOfWeek == that.startDayOfWeek &&
+                        && endMode == that.endMode
-                 startTime == that.startTime &&
+                        && endMonth == that.endMonth
-                 startTimeMode == that.startTimeMode &&
+                        && endDay == that.endDay
-                 endMode == that.endMode &&
+                        && endDayOfWeek == that.endDayOfWeek
-                 endMonth == that.endMonth &&
+                        && endTime == that.endTime
-                 endDay == that.endDay &&
+                        && endTimeMode == that.endTimeMode
-                 endDayOfWeek == that.endDayOfWeek &&
+                        && startYear == that.startYear)
-                 endTime == that.endTime &&
+                    );
-                 endTimeMode == that.endTimeMode &&
-                 startYear == that.startYear));
     }
 
     /**

src/java.base/share/classes/java/util/TreeMap.java

@@ -1341,18 +1341,16 @@ public class TreeMap<K,V>
         }
 
         public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> entry))
                 return false;
-            Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
             Object value = entry.getValue();
             Entry<K,V> p = getEntry(entry.getKey());
             return p != null && valEquals(p.getValue(), value);
         }
 
         public boolean remove(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> entry))
                 return false;
-            Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
             Object value = entry.getValue();
             Entry<K,V> p = getEntry(entry.getKey());
             if (p != null && valEquals(p.getValue(), value)) {
@@ -1963,9 +1961,8 @@ public class TreeMap<K,V>
             }
 
             public boolean contains(Object o) {
-                if (!(o instanceof Map.Entry))
+                if (!(o instanceof Entry<?, ?> entry))
                     return false;
-                Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
                 Object key = entry.getKey();
                 if (!inRange(key))
                     return false;
@@ -1975,9 +1972,8 @@ public class TreeMap<K,V>
             }
 
             public boolean remove(Object o) {
-                if (!(o instanceof Map.Entry))
+                if (!(o instanceof Entry<?, ?> entry))
                     return false;
-                Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
                 Object key = entry.getKey();
                 if (!inRange(key))
                     return false;
@@ -2425,11 +2421,9 @@ public class TreeMap<K,V>
         }
 
         public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> e
-                return false;
+                    && valEquals(key,e.getKey())
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                    && valEquals(value,e.getValue());
-
-            return valEquals(key,e.getKey()) && valEquals(value,e.getValue());
         }
 
         public int hashCode() {

src/java.base/share/classes/java/util/TreeSet.java

@@ -299,9 +299,8 @@ public class TreeSet<E> extends AbstractSet<E>
         // Use linear-time version if applicable
         if (m.size()==0 && c.size() > 0 &&
             c instanceof SortedSet &&
-            m instanceof TreeMap) {
+                m instanceof TreeMap<E, Object> map) {
             SortedSet<? extends E> set = (SortedSet<? extends E>) c;
-            TreeMap<E,Object> map = (TreeMap<E, Object>) m;
             if (Objects.equals(set.comparator(), map.comparator())) {
                 map.addAllForTreeSet(set, PRESENT);
                 return true;

src/java.base/share/classes/java/util/WeakHashMap.java

@@ -619,10 +619,9 @@ public class WeakHashMap<K,V>
 
     /** Special version of remove needed by Entry set */
     boolean removeMapping(Object o) {
-        if (!(o instanceof Map.Entry))
+        if (!(o instanceof Map.Entry<?, ?> entry))
             return false;
         Entry<K,V>[] tab = getTable();
-        Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
         Object k = maskNull(entry.getKey());
         int h = hash(k);
         int i = indexFor(h, tab.length);
@@ -737,9 +736,8 @@ public class WeakHashMap<K,V>
         }
 
         public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
+            if (!(o instanceof Map.Entry<?, ?> e))
                 return false;
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
             K k1 = getKey();
             Object k2 = e.getKey();
             if (k1 == k2 || (k1 != null && k1.equals(k2))) {
@@ -977,11 +975,9 @@ public class WeakHashMap<K,V>
         }
 
         public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
+            return o instanceof Map.Entry<?, ?> e
-                return false;
+                    && getEntry(e.getKey()) != null
-            Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+                    && getEntry(e.getKey()).equals(e);
-            Entry<K,V> candidate = getEntry(e.getKey());
-            return candidate != null && candidate.equals(e);
         }
 
         public boolean remove(Object o) {

src/java.base/share/classes/java/util/jar/Attributes.java

@@ -514,12 +514,8 @@ public class Attributes implements Map<Object,Object>, Cloneable {
             if (this == o) {
                 return true;
             }
-            if (o instanceof Name) {
+            return o instanceof Name other
-                Name other = (Name)o;
+                    && other.name.equalsIgnoreCase(name);
-                return other.name.equalsIgnoreCase(name);
-            } else {
-                return false;
-            }
         }
 
         /**

src/java.base/share/classes/java/util/jar/JarVerifier.java

@@ -551,10 +551,9 @@ class JarVerifier {
      * Match CodeSource to a CodeSigner[] in the signer cache.
      */
     private CodeSigner[] findMatchingSigners(CodeSource cs) {
-        if (cs instanceof VerifierCodeSource) {
+        if (cs instanceof VerifierCodeSource vcs) {
-            VerifierCodeSource vcs = (VerifierCodeSource) cs;
             if (vcs.isSameDomain(csdomain)) {
-                return ((VerifierCodeSource) cs).getPrivateSigners();
+                return vcs.getPrivateSigners();
             }
         }
 
@@ -617,8 +616,7 @@ class JarVerifier {
             if (obj == this) {
                 return true;
             }
-            if (obj instanceof VerifierCodeSource) {
+            if (obj instanceof VerifierCodeSource that) {
-                VerifierCodeSource that = (VerifierCodeSource) obj;
 
                 /*
                  * Only compare against other per-signer singletons constructed

src/java.base/share/classes/java/util/jar/Manifest.java

@@ -379,13 +379,9 @@ public class Manifest implements Cloneable {
      * the same main Attributes and entries
      */
     public boolean equals(Object o) {
-        if (o instanceof Manifest) {
+        return o instanceof Manifest m
-            Manifest m = (Manifest)o;
+                && attr.equals(m.getMainAttributes())
-            return attr.equals(m.getMainAttributes()) &&
+                && entries.equals(m.getEntries());
-                   entries.equals(m.getEntries());
-        } else {
-            return false;
-        }
     }
 
     /**

src/java.base/share/classes/java/util/regex/Pattern.java

@@ -3083,8 +3083,7 @@ loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
         if (saveTCNCount < topClosureNodes.size())
             topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
 
-        if (node instanceof Ques) {
+        if (node instanceof Ques ques) {
-            Ques ques = (Ques) node;
             if (ques.type == Qtype.POSSESSIVE) {
                 root = node;
                 return node;
@@ -3098,8 +3097,7 @@ loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
             }
             root = tail;
             return head;
-        } else if (node instanceof Curly) {
+        } else if (node instanceof Curly curly) {
-            Curly curly = (Curly) node;
             if (curly.type == Qtype.POSSESSIVE) {
                 root = node;
                 return node;

src/java.base/share/classes/java/util/regex/PrintPattern.java

@@ -131,21 +131,18 @@ class PrintPattern {
                 node = loop;
             } else if (node instanceof Pattern.Loop) {
                 return;  // stop here, body.next -> loop
-            } else if (node instanceof Pattern.Curly) {
+            } else if (node instanceof Pattern.Curly c) {
-                Pattern.Curly c = (Pattern.Curly)node;
                 str = "Curly " + c.type + " " + toStringRange(c.cmin, c.cmax);
                 print(node, str, depth);
                 walk(c.atom, depth);
                 print("/Curly", depth);
-            } else if (node instanceof Pattern.GroupCurly) {
+            } else if (node instanceof Pattern.GroupCurly gc) {
-                Pattern.GroupCurly gc = (Pattern.GroupCurly)node;
                 str = "GroupCurly " + gc.groupIndex / 2 +
                       ", " + gc.type + " " + toStringRange(gc.cmin, gc.cmax);
                 print(node, str, depth);
                 walk(gc.atom, depth);
                 print("/GroupCurly", depth);
-            } else if (node instanceof Pattern.GroupHead) {
+            } else if (node instanceof Pattern.GroupHead head) {
-                Pattern.GroupHead head = (Pattern.GroupHead)node;
                 Pattern.GroupTail tail = head.tail;
                 print(head, "Group.head " + (tail.groupIndex / 2), depth);
                 walk(head.next, depth);
@@ -157,8 +154,7 @@ class PrintPattern {
                 print(node, "Ques " + ((Pattern.Ques)node).type, depth);
                 walk(((Pattern.Ques)node).atom, depth);
                 print("/Ques", depth);
-            } else if (node instanceof Pattern.Branch) {
+            } else if (node instanceof Pattern.Branch b) {
-                Pattern.Branch b = (Pattern.Branch)node;
                 print(b, name, depth);
                 int i = 0;
                 while (true) {
@@ -186,8 +182,7 @@ class PrintPattern {
                 str = name + "  \"" +
                       toStringCPS(((Pattern.SliceNode)node).buffer) + "\"";
                 print(node, str, depth);
-            } else if (node instanceof Pattern.CharPropertyGreedy) {
+            } else if (node instanceof Pattern.CharPropertyGreedy gcp) {
-                Pattern.CharPropertyGreedy gcp = (Pattern.CharPropertyGreedy)node;
                 String pstr = pmap.get(gcp.predicate);
                 if (pstr == null)
                     pstr = gcp.predicate.toString();

src/java.base/share/classes/java/util/zip/ZipFile.java

@@ -1218,8 +1218,7 @@ public class ZipFile implements ZipConstants, Closeable {
             }
 
             public boolean equals(Object obj) {
-                if (obj instanceof Key) {
+                if (obj instanceof Key key) {
-                    Key key = (Key)obj;
                     if (key.utf8 != utf8) {
                         return false;
                     }