fix and enforce more errorprone checks (#1663)

enforces the following checks:
https://errorprone.info/bugpattern/ObjectsHashCodePrimitive
https://errorprone.info/bugpattern/OptionalMapToOptional
https://errorprone.info/bugpattern/StringCharset
https://errorprone.info/bugpattern/VariableNameSameAsType

Author: XN137

api/iceberg-service/src/main/java/org/apache/polaris/service/types/NotificationType.java

@@ -19,7 +19,6 @@
 package org.apache.polaris.service.types;
 
 import java.util.Arrays;
-import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Collectors;
@@ -84,9 +83,9 @@ public static Optional<NotificationType> lookupByName(String name) {
       return Optional.empty();
     }
 
-    for (NotificationType NotificationType : NotificationType.values()) {
-      if (name.toUpperCase(Locale.ROOT).equals(NotificationType.name())) {
-        return Optional.of(NotificationType);
+    for (NotificationType notificationType : NotificationType.values()) {
+      if (name.equalsIgnoreCase(notificationType.name())) {
+        return Optional.of(notificationType);
       }
     }
     return Optional.empty();

codestyle/errorprone-rules.properties

@@ -227,6 +227,12 @@ UseCorrectAssertInTests=ERROR
 ConstantPatternCompile=ERROR
 # Variables initialized with Pattern#compile calls on constants can be constants
 
+ObjectsHashCodePrimitive=ERROR
+# Objects.hashCode(Object o) should not be passed a primitive value
+
+OptionalMapToOptional=ERROR
+# Mapping to another Optional will yield a nested Optional. Did you mean flatMap?
+
 PrimitiveArrayPassedToVarargsMethod=ERROR
 # Passing a primitive array to a varargs method is usually wrong
 
@@ -239,6 +245,9 @@ RedundantThrows=ERROR
 StringCaseLocaleUsage=ERROR
 # Specify a `Locale` when calling `String#to{Lower,Upper}Case`. (Note: there are multiple suggested fixes; the third may be most appropriate if you're dealing with ASCII Strings.)
 
+StringCharset=ERROR
+# Prefer StandardCharsets over using string names for charsets
+
 StronglyTypeByteString=WARN
 # This primitive byte array is only used to construct ByteStrings. It would be clearer to strongly type the field instead.
 
@@ -254,6 +263,9 @@ TransientMisuse=ERROR
 UrlInSee=ERROR
 # URLs should not be used in @see tags; they are designed for Java elements which could be used with @link.
 
+VariableNameSameAsType=ERROR
+# variableName and type with the same name would refer to the static field instead of the class
+
 ####################################################################################################
 # Experimental : SUGGESTION
 # See https://errorprone.info/bugpatterns

polaris-core/src/main/java/org/apache/polaris/core/secrets/UnsafeInMemorySecretsManager.java

@@ -19,7 +19,7 @@
 package org.apache.polaris.core.secrets;
 
 import jakarta.annotation.Nonnull;
-import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.security.SecureRandom;
 import java.util.Base64;
 import java.util.HashMap;
@@ -54,12 +54,7 @@ public UserSecretReference writeSecret(
     // secret as well as the secretReferencePayload to recover the original secret, we'll use
     // basic XOR encryption and store the randomly generated key in the reference payload.
     // A production implementation will typically use a standard crypto library if applicable.
-    byte[] secretBytes;
-    try {
-      secretBytes = secret.getBytes("UTF-8");
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException(e);
-    }
+    byte[] secretBytes = secret.getBytes(StandardCharsets.UTF_8);
     byte[] oneTimeKey = new byte[secretBytes.length];
     byte[] cipherTextBytes = new byte[secretBytes.length];
 
@@ -143,11 +138,7 @@ public String readSecret(@Nonnull UserSecretReference secretReference) {
       secretBytes[i] = (byte) (cipherTextBytes[i] ^ oneTimeKey[i]);
     }
 
-    try {
-      return new String(secretBytes, "UTF-8");
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException(e);
-    }
+    return new String(secretBytes, StandardCharsets.UTF_8);
   }
 
   /** {@inheritDoc} */

polaris-core/src/main/java/org/apache/polaris/core/storage/PolarisStorageIntegration.java

@@ -21,7 +21,6 @@
 import jakarta.annotation.Nonnull;
 import java.util.EnumMap;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import org.apache.polaris.core.PolarisDiagnostics;
 
@@ -129,7 +128,7 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-      return Objects.hashCode(success);
+      return Boolean.hashCode(success);
     }
 
     @Override

quarkus/service/src/main/java/org/apache/polaris/service/quarkus/config/ProductionReadinessChecks.java

@@ -151,7 +151,7 @@ public ProductionReadinessCheck checkTokenBrokers(
                   if (config
                       .tokenBroker()
                       .symmetricKey()
-                      .map(SymmetricKeyConfiguration::secret)
+                      .flatMap(SymmetricKeyConfiguration::secret)
                       .isPresent()) {
                     errors.add(
                         Error.of(