8258422: Cleanup unnecessary null comparison before instanceof check in java.base

src/java.base/share/classes/java/io/File.java

@@ -2190,8 +2190,8 @@ public int compareTo(File pathname) {
      *          {@code false} otherwise
      */
     public boolean equals(Object obj) {
-        if ((obj != null) && (obj instanceof File)) {
-            return compareTo((File)obj) == 0;
+        if (obj instanceof File file) {
+            return compareTo(file) == 0;
         }
         return false;
     }

src/java.base/share/classes/java/lang/reflect/Constructor.java

@@ -308,8 +308,7 @@ public Type[] getGenericExceptionTypes() {
      * same formal parameter types.
      */
     public boolean equals(Object obj) {
-        if (obj != null && obj instanceof Constructor) {
-            Constructor<?> other = (Constructor<?>)obj;
+        if (obj instanceof Constructor<?> other) {
             if (getDeclaringClass() == other.getDeclaringClass()) {
                 return equalParamTypes(parameterTypes, other.parameterTypes);
             }

src/java.base/share/classes/java/lang/reflect/Field.java

@@ -279,8 +279,7 @@ public Type getGenericType() {
      * and type.
      */
     public boolean equals(Object obj) {
-        if (obj != null && obj instanceof Field) {
-            Field other = (Field)obj;
+        if (obj instanceof Field other) {
             return (getDeclaringClass() == other.getDeclaringClass())
                 && (getName() == other.getName())
                 && (getType() == other.getType());

src/java.base/share/classes/java/lang/reflect/Method.java

@@ -358,8 +358,7 @@ public Type[] getGenericExceptionTypes() {
      * and formal parameter types and return type.
      */
     public boolean equals(Object obj) {
-        if (obj != null && obj instanceof Method) {
-            Method other = (Method)obj;
+        if (obj instanceof Method other) {
             if ((getDeclaringClass() == other.getDeclaringClass())
                 && (getName() == other.getName())) {
                 if (!returnType.equals(other.getReturnType()))

src/java.base/share/classes/java/net/AbstractPlainDatagramSocketImpl.java

@@ -235,7 +235,7 @@ protected void leave(InetAddress inetaddr) throws IOException {
 
     protected void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
         throws IOException {
-        if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress))
+        if (!(mcastaddr instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
         join(((InetSocketAddress)mcastaddr).getAddress(), netIf);
     }
@@ -253,7 +253,7 @@ protected abstract void join(InetAddress inetaddr, NetworkInterface netIf)
      */
     protected void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
         throws IOException {
-        if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress))
+        if (!(mcastaddr instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
         leave(((InetSocketAddress)mcastaddr).getAddress(), netIf);
     }
@@ -292,7 +292,7 @@ public void setOption(int optID, Object o) throws SocketException {
              * PlainSocketImpl.setOption().
              */
          case SO_TIMEOUT:
-             if (o == null || !(o instanceof Integer)) {
+             if (!(o instanceof Integer)) {
                  throw new SocketException("bad argument for SO_TIMEOUT");
              }
              int tmp = ((Integer) o).intValue();
@@ -301,45 +301,45 @@ public void setOption(int optID, Object o) throws SocketException {
              timeout = tmp;
              return;
          case IP_TOS:
-             if (o == null || !(o instanceof Integer)) {
+             if (!(o instanceof Integer)) {
                  throw new SocketException("bad argument for IP_TOS");
              }
              trafficClass = ((Integer)o).intValue();
              break;
          case SO_REUSEADDR:
-             if (o == null || !(o instanceof Boolean)) {
+             if (!(o instanceof Boolean)) {
                  throw new SocketException("bad argument for SO_REUSEADDR");
              }
              break;
          case SO_BROADCAST:
-             if (o == null || !(o instanceof Boolean)) {
+             if (!(o instanceof Boolean)) {
                  throw new SocketException("bad argument for SO_BROADCAST");
              }
              break;
          case SO_BINDADDR:
              throw new SocketException("Cannot re-bind Socket");
          case SO_RCVBUF:
          case SO_SNDBUF:
-             if (o == null || !(o instanceof Integer) ||
+             if (!(o instanceof Integer) ||
                  ((Integer)o).intValue() < 0) {
                  throw new SocketException("bad argument for SO_SNDBUF or " +
                                            "SO_RCVBUF");
              }
              break;
          case IP_MULTICAST_IF:
-             if (o == null || !(o instanceof InetAddress))
+             if (!(o instanceof InetAddress))
                  throw new SocketException("bad argument for IP_MULTICAST_IF");
              break;
          case IP_MULTICAST_IF2:
-             if (o == null || !(o instanceof NetworkInterface))
+             if (!(o instanceof NetworkInterface))
                  throw new SocketException("bad argument for IP_MULTICAST_IF2");
              break;
          case IP_MULTICAST_LOOP:
-             if (o == null || !(o instanceof Boolean))
+             if (!(o instanceof Boolean))
                  throw new SocketException("bad argument for IP_MULTICAST_LOOP");
              break;
          case SO_REUSEPORT:
-             if (o == null || !(o instanceof Boolean)) {
+             if (!(o instanceof Boolean)) {
                  throw new SocketException("bad argument for SO_REUSEPORT");
              }
              if (!supportedOptions().contains(StandardSocketOptions.SO_REUSEPORT)) {

src/java.base/share/classes/java/net/AbstractPlainSocketImpl.java

@@ -213,7 +213,7 @@ protected void connect(SocketAddress address, int timeout)
             throws IOException {
         boolean connected = false;
         try {
-            if (address == null || !(address instanceof InetSocketAddress))
+            if (!(address instanceof InetSocketAddress))
                 throw new IllegalArgumentException("unsupported address type");
             InetSocketAddress addr = (InetSocketAddress) address;
             if (addr.isUnresolved())
@@ -259,59 +259,59 @@ public void setOption(int opt, Object val) throws SocketException {
              * PlainSocketImpl.setOption().
              */
         case SO_LINGER:
-            if (val == null || (!(val instanceof Integer) && !(val instanceof Boolean)))
+            if (!(val instanceof Integer) && !(val instanceof Boolean))
                 throw new SocketException("Bad parameter for option");
             if (val instanceof Boolean) {
                 /* true only if disabling - enabling should be Integer */
                 on = false;
             }
             break;
         case SO_TIMEOUT:
-            if (val == null || (!(val instanceof Integer)))
+            if (!(val instanceof Integer))
                 throw new SocketException("Bad parameter for SO_TIMEOUT");
             int tmp = ((Integer) val).intValue();
             if (tmp < 0)
                 throw new IllegalArgumentException("timeout < 0");
             timeout = tmp;
             break;
         case IP_TOS:
-             if (val == null || !(val instanceof Integer)) {
+             if (!(val instanceof Integer)) {
                  throw new SocketException("bad argument for IP_TOS");
              }
              trafficClass = ((Integer)val).intValue();
              break;
         case SO_BINDADDR:
             throw new SocketException("Cannot re-bind socket");
         case TCP_NODELAY:
-            if (val == null || !(val instanceof Boolean))
+            if (!(val instanceof Boolean))
                 throw new SocketException("bad parameter for TCP_NODELAY");
             on = ((Boolean)val).booleanValue();
             break;
         case SO_SNDBUF:
         case SO_RCVBUF:
-            if (val == null || !(val instanceof Integer) ||
+            if (!(val instanceof Integer) ||
                 !(((Integer)val).intValue() > 0)) {
                 throw new SocketException("bad parameter for SO_SNDBUF " +
                                           "or SO_RCVBUF");
             }
             break;
         case SO_KEEPALIVE:
-            if (val == null || !(val instanceof Boolean))
+            if (!(val instanceof Boolean))
                 throw new SocketException("bad parameter for SO_KEEPALIVE");
             on = ((Boolean)val).booleanValue();
             break;
         case SO_OOBINLINE:
-            if (val == null || !(val instanceof Boolean))
+            if (!(val instanceof Boolean))
                 throw new SocketException("bad parameter for SO_OOBINLINE");
             on = ((Boolean)val).booleanValue();
             break;
         case SO_REUSEADDR:
-            if (val == null || !(val instanceof Boolean))
+            if (!(val instanceof Boolean))
                 throw new SocketException("bad parameter for SO_REUSEADDR");
             on = ((Boolean)val).booleanValue();
             break;
         case SO_REUSEPORT:
-            if (val == null || !(val instanceof Boolean))
+            if (!(val instanceof Boolean))
                 throw new SocketException("bad parameter for SO_REUSEPORT");
             if (!supportedOptions().contains(StandardSocketOptions.SO_REUSEPORT))
                 throw new UnsupportedOperationException("unsupported option");

src/java.base/share/classes/java/net/DatagramPacket.java

@@ -352,7 +352,7 @@ public synchronized void setPort(int iport) {
      * @since   1.4
      */
     public synchronized void setSocketAddress(SocketAddress address) {
-        if (address == null || !(address instanceof InetSocketAddress))
+        if (!(address instanceof InetSocketAddress))
             throw new IllegalArgumentException("unsupported address type");
         InetSocketAddress addr = (InetSocketAddress) address;
         if (addr.isUnresolved())

src/java.base/share/classes/java/net/HttpConnectSocketImpl.java

@@ -102,7 +102,7 @@ protected void connect(InetAddress address, int port) throws IOException {
     protected void connect(SocketAddress endpoint, int timeout)
         throws IOException
     {
-        if (endpoint == null || !(endpoint instanceof InetSocketAddress))
+        if (!(endpoint instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
         final InetSocketAddress epoint = (InetSocketAddress)endpoint;
         String destHost = epoint.isUnresolved() ? epoint.getHostName()

src/java.base/share/classes/java/net/Inet4Address.java

@@ -352,8 +352,8 @@ public int hashCode() {
      * @see     java.net.InetAddress#getAddress()
      */
     public boolean equals(Object obj) {
-        return (obj != null) && (obj instanceof Inet4Address) &&
-            (((InetAddress)obj).holder().getAddress() == holder().getAddress());
+        return (obj instanceof Inet4Address inet4Address) &&
+            inet4Address.holder().getAddress() == holder().getAddress();
     }
 
     // Utilities

src/java.base/share/classes/java/net/Inet6Address.java

@@ -878,7 +878,7 @@ public int hashCode() {
      */
     @Override
     public boolean equals(Object obj) {
-        if (obj == null || !(obj instanceof Inet6Address))
+        if (!(obj instanceof Inet6Address))
             return false;
 
         Inet6Address inetAddr = (Inet6Address)obj;

src/java.base/share/classes/java/net/InetSocketAddress.java

@@ -119,7 +119,7 @@ public String toString() {
 
         @Override
         public final boolean equals(Object obj) {
-            if (obj == null || !(obj instanceof InetSocketAddressHolder))
+            if (!(obj instanceof InetSocketAddressHolder))
                 return false;
             InetSocketAddressHolder that = (InetSocketAddressHolder)obj;
             boolean sameIP;
@@ -409,7 +409,7 @@ public String toString() {
      */
     @Override
     public final boolean equals(Object obj) {
-        if (obj == null || !(obj instanceof InetSocketAddress))
+        if (!(obj instanceof InetSocketAddress))
             return false;
         return holder.equals(((InetSocketAddress) obj).holder);
     }

src/java.base/share/classes/java/net/NetMulticastSocket.java

@@ -801,7 +801,7 @@ public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
         if (isClosed())
             throw new SocketException("Socket is closed");
 
-        if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress))
+        if (!(mcastaddr instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
 
         if (oldImpl)
@@ -826,7 +826,7 @@ public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
         if (isClosed())
             throw new SocketException("Socket is closed");
 
-        if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress))
+        if (!(mcastaddr instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
 
         if (oldImpl)

src/java.base/share/classes/java/net/Proxy.java

@@ -146,7 +146,7 @@ public String toString() {
      * @see java.net.InetSocketAddress#equals(java.lang.Object)
      */
     public final boolean equals(Object obj) {
-        if (obj == null || !(obj instanceof Proxy))
+        if (!(obj instanceof Proxy))
             return false;
         Proxy p = (Proxy) obj;
         if (p.type() == type()) {

src/java.base/share/classes/java/net/SocksSocketImpl.java

@@ -272,7 +272,7 @@ protected void connect(SocketAddress endpoint, int timeout) throws IOException {
         }
 
         SecurityManager security = System.getSecurityManager();
-        if (endpoint == null || !(endpoint instanceof InetSocketAddress))
+        if (!(endpoint instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
         InetSocketAddress epoint = (InetSocketAddress) endpoint;
         if (security != null) {

src/java.base/share/classes/java/nio/file/attribute/AclEntry.java

@@ -342,7 +342,7 @@ public Set<AclEntryFlag> flags() {
     public boolean equals(Object ob) {
         if (ob == this)
             return true;
-        if (ob == null || !(ob instanceof AclEntry))
+        if (!(ob instanceof AclEntry))
             return false;
         AclEntry other = (AclEntry)ob;
         if (this.type != other.type)

src/java.base/share/classes/jdk/internal/misc/Signal.java

@@ -102,7 +102,7 @@ public boolean equals(Object other) {
         if (this == other) {
             return true;
         }
-        if (other == null || !(other instanceof Signal)) {
+        if (!(other instanceof Signal)) {
             return false;
         }
         Signal other1 = (Signal)other;

src/java.base/share/classes/sun/net/www/protocol/http/Negotiator.java

@@ -66,8 +66,8 @@ static Negotiator getNegotiator(HttpCallerInfo hci) {
         } catch (ReflectiveOperationException roe) {
             finest(roe);
             Throwable t = roe.getCause();
-            if (t != null && t instanceof Exception)
-                finest((Exception)t);
+            if (t instanceof Exception exception)
+                finest(exception);
             return null;
         }
     }

src/java.base/share/classes/sun/net/www/protocol/https/HttpsClient.java

@@ -426,7 +426,7 @@ protected Socket createSocket() throws IOException {
             // unconnected sockets have not been implemented.
             //
             Throwable t = se.getCause();
-            if (t != null && t instanceof UnsupportedOperationException) {
+            if (t instanceof UnsupportedOperationException) {
                 return super.createSocket();
             } else {
                 throw se;

src/java.base/share/classes/sun/nio/ch/DatagramSocketAdaptor.java

@@ -504,7 +504,7 @@ public void leaveGroup(InetAddress group) throws IOException {
      * @throws SocketException if group is not a multicast address
      */
     private static InetAddress checkGroup(SocketAddress mcastaddr) throws SocketException {
-        if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress))
+        if (!(mcastaddr instanceof InetSocketAddress))
             throw new IllegalArgumentException("Unsupported address type");
         InetAddress group = ((InetSocketAddress) mcastaddr).getAddress();
         if (group == null)

src/java.base/share/classes/sun/nio/fs/PollingWatchService.java

@@ -149,8 +149,8 @@ public PollingWatchKey run() throws IOException {
                 });
         } catch (PrivilegedActionException pae) {
             Throwable cause = pae.getCause();
-            if (cause != null && cause instanceof IOException)
-                throw (IOException)cause;
+            if (cause instanceof IOException ioe)
+                throw ioe;
             throw new AssertionError(pae);
         }
     }

src/java.base/windows/classes/sun/nio/fs/WindowsPath.java

@@ -798,8 +798,8 @@ public int compareTo(Path obj) {
 
     @Override
     public boolean equals(Object obj) {
-        if ((obj != null) && (obj instanceof WindowsPath)) {
-            return compareTo((Path)obj) == 0;
+        if (obj instanceof WindowsPath path) {
+            return compareTo(path) == 0;
         }
         return false;
     }