Polish "Add SAP HANA duplicate key exception error code"

See gh-31554

spring-jdbc/src/test/java/org/springframework/jdbc/support/SQLStateSQLExceptionTranslatorTests.java

@@ -81,6 +81,11 @@ public class SQLStateSQLExceptionTranslatorTests {
 		doTest("23000", 2627, DuplicateKeyException.class);
 	}
 
+	@Test
+	public void translateDuplicateKeySapHana() {
+		doTest("23000", 301, DuplicateKeyException.class);
+	}
+
 	@Test
 	public void translateDataAccessResourceFailure() {
 		doTest("53", DataAccessResourceFailureException.class);

spring-r2dbc/src/main/java/org/springframework/r2dbc/connection/ConnectionFactoryUtils.java

@@ -16,6 +16,8 @@
 
 package org.springframework.r2dbc.connection;
 
+import java.util.Set;
+
 import io.r2dbc.spi.Connection;
 import io.r2dbc.spi.ConnectionFactory;
 import io.r2dbc.spi.R2dbcBadGrammarException;
@@ -69,6 +71,14 @@ public abstract class ConnectionFactoryUtils {
 	 */
 	public static final int CONNECTION_SYNCHRONIZATION_ORDER = 1000;
 
+	private static final Set<Integer> DUPLICATE_KEY_ERROR_CODES = Set.of(
+			1,	   // Oracle
+			301,   // Sap Hana
+			1062,  // MySQL/MariaDB
+			2601,  // MS SQL Server
+			2627   // MS SQL Server
+	);
+
 
 	/**
 	 * Obtain a {@link Connection} from the given {@link ConnectionFactory}.
@@ -255,8 +265,7 @@ public abstract class ConnectionFactoryUtils {
 	 */
 	static boolean indicatesDuplicateKey(@Nullable String sqlState, int errorCode) {
 		return ("23505".equals(sqlState) ||
-				("23000".equals(sqlState) &&
-						(errorCode == 1 || errorCode == 1062 || errorCode == 2601 || errorCode == 2627)));
+				("23000".equals(sqlState) && DUPLICATE_KEY_ERROR_CODES.contains(errorCode)));
 	}
 
 	/**

spring-r2dbc/src/test/java/org/springframework/r2dbc/connection/ConnectionFactoryUtilsUnitTests.java

@@ -100,6 +100,10 @@ public class ConnectionFactoryUtilsUnitTests {
 				new R2dbcDataIntegrityViolationException("reason", "23000", 1));
 		assertThat(exception).isExactlyInstanceOf(DuplicateKeyException.class);
 
+		exception = ConnectionFactoryUtils.convertR2dbcException("", "",
+				new R2dbcDataIntegrityViolationException("reason", "23000", 301));
+		assertThat(exception).isExactlyInstanceOf(DuplicateKeyException.class);
+
 		exception = ConnectionFactoryUtils.convertR2dbcException("", "",
 				new R2dbcDataIntegrityViolationException("reason", "23000", 1062));
 		assertThat(exception).isExactlyInstanceOf(DuplicateKeyException.class);