Apply "instanceof pattern matching" in spring-jdbc

This commit also applies additional clean-up tasks such as the following.

- final fields

This has only been applied to `src/main/java`.

spring-jdbc/src/main/java/org/springframework/jdbc/core/ArgumentPreparedStatementSetter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -61,8 +61,7 @@ public class ArgumentPreparedStatementSetter implements PreparedStatementSetter,
 	 * @throws SQLException if thrown by PreparedStatement methods
 	 */
 	protected void doSetValue(PreparedStatement ps, int parameterPosition, Object argValue) throws SQLException {
-		if (argValue instanceof SqlParameterValue) {
+		if (argValue instanceof SqlParameterValue paramValue) {
-			SqlParameterValue paramValue = (SqlParameterValue) argValue;
 			StatementCreatorUtils.setParameterValue(ps, parameterPosition, paramValue, paramValue.getValue());
 		}
 		else {

spring-jdbc/src/main/java/org/springframework/jdbc/core/ArgumentTypePreparedStatementSetter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -64,8 +64,7 @@ public class ArgumentTypePreparedStatementSetter implements PreparedStatementSet
 				if (arg instanceof Collection && this.argTypes[i] != Types.ARRAY) {
 					Collection<?> entries = (Collection<?>) arg;
 					for (Object entry : entries) {
-						if (entry instanceof Object[]) {
+						if (entry instanceof Object[] valueArray) {
-							Object[] valueArray = ((Object[]) entry);
 							for (Object argValue : valueArray) {
 								doSetValue(ps, parameterPosition, this.argTypes[i], argValue);
 								parameterPosition++;

spring-jdbc/src/main/java/org/springframework/jdbc/core/BatchUpdateUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -62,8 +62,7 @@ public abstract class BatchUpdateUtils {
 		int colIndex = 0;
 		for (Object value : values) {
 			colIndex++;
-			if (value instanceof SqlParameterValue) {
+			if (value instanceof SqlParameterValue paramValue) {
-				SqlParameterValue paramValue = (SqlParameterValue) value;
 				StatementCreatorUtils.setParameterValue(ps, colIndex, paramValue, paramValue.getValue());
 			}
 			else {

spring-jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -1094,8 +1094,7 @@ public class JdbcTemplate extends JdbcAccessor implements JdbcOperations {
 						int colIndex = 0;
 						for (Object value : values) {
 							colIndex++;
-							if (value instanceof SqlParameterValue) {
+							if (value instanceof SqlParameterValue paramValue) {
-								SqlParameterValue paramValue = (SqlParameterValue) value;
 								StatementCreatorUtils.setParameterValue(ps, colIndex, paramValue, paramValue.getValue());
 							}
 							else {
@@ -1337,8 +1336,7 @@ public class JdbcTemplate extends JdbcAccessor implements JdbcOperations {
 		Map<String, Object> results = CollectionUtils.newLinkedHashMap(parameters.size());
 		int sqlColIndex = 1;
 		for (SqlParameter param : parameters) {
-			if (param instanceof SqlOutParameter) {
+			if (param instanceof SqlOutParameter outParam) {
-				SqlOutParameter outParam = (SqlOutParameter) param;
 				Assert.state(outParam.getName() != null, "Anonymous parameters not allowed");
 				SqlReturnType returnType = outParam.getSqlReturnType();
 				if (returnType != null) {

spring-jdbc/src/main/java/org/springframework/jdbc/core/PreparedStatementCreatorFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.sql.Statement;
 import java.sql.Types;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -228,7 +229,7 @@ public class PreparedStatementCreatorFactory {
 					ps = con.prepareStatement(this.actualSql, generatedKeysColumnNames);
 				}
 				else {
-					ps = con.prepareStatement(this.actualSql, PreparedStatement.RETURN_GENERATED_KEYS);
+					ps = con.prepareStatement(this.actualSql, Statement.RETURN_GENERATED_KEYS);
 				}
 			}
 			else if (resultSetType == ResultSet.TYPE_FORWARD_ONLY && !updatableResults) {
@@ -251,8 +252,7 @@ public class PreparedStatementCreatorFactory {
 				SqlParameter declaredParameter;
 				// SqlParameterValue overrides declared parameter meta-data, in particular for
 				// independence from the declared parameter position in case of named parameters.
-				if (in instanceof SqlParameterValue) {
+				if (in instanceof SqlParameterValue paramValue) {
-					SqlParameterValue paramValue = (SqlParameterValue) in;
 					in = paramValue.getValue();
 					declaredParameter = paramValue;
 				}
@@ -268,8 +268,7 @@ public class PreparedStatementCreatorFactory {
 				if (in instanceof Iterable && declaredParameter.getSqlType() != Types.ARRAY) {
 					Iterable<?> entries = (Iterable<?>) in;
 					for (Object entry : entries) {
-						if (entry instanceof Object[]) {
+						if (entry instanceof Object[] valueArray) {
-							Object[] valueArray = (Object[]) entry;
 							for (Object argValue : valueArray) {
 								StatementCreatorUtils.setParameterValue(ps, sqlColIndx++, declaredParameter, argValue);
 							}

spring-jdbc/src/main/java/org/springframework/jdbc/core/StatementCreatorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -202,8 +202,7 @@ public abstract class StatementCreatorUtils {
 		Object inValueToUse = inValue;
 
 		// override type info?
-		if (inValue instanceof SqlParameterValue) {
+		if (inValue instanceof SqlParameterValue parameterValue) {
-			SqlParameterValue parameterValue = (SqlParameterValue) inValue;
 			if (logger.isDebugEnabled()) {
 				logger.debug("Overriding type info with runtime info from SqlParameterValue: column index " + paramIndex +
 						", SQL type " + parameterValue.getSqlType() + ", type name " + parameterValue.getTypeName());
@@ -350,8 +349,7 @@ public abstract class StatementCreatorUtils {
 					ps.setDate(paramIndex, new java.sql.Date(((java.util.Date) inValue).getTime()));
 				}
 			}
-			else if (inValue instanceof Calendar) {
+			else if (inValue instanceof Calendar cal) {
-				Calendar cal = (Calendar) inValue;
 				ps.setDate(paramIndex, new java.sql.Date(cal.getTime().getTime()), cal);
 			}
 			else {
@@ -367,8 +365,7 @@ public abstract class StatementCreatorUtils {
 					ps.setTime(paramIndex, new java.sql.Time(((java.util.Date) inValue).getTime()));
 				}
 			}
-			else if (inValue instanceof Calendar) {
+			else if (inValue instanceof Calendar cal) {
-				Calendar cal = (Calendar) inValue;
 				ps.setTime(paramIndex, new java.sql.Time(cal.getTime().getTime()), cal);
 			}
 			else {
@@ -384,8 +381,7 @@ public abstract class StatementCreatorUtils {
 					ps.setTimestamp(paramIndex, new java.sql.Timestamp(((java.util.Date) inValue).getTime()));
 				}
 			}
-			else if (inValue instanceof Calendar) {
+			else if (inValue instanceof Calendar cal) {
-				Calendar cal = (Calendar) inValue;
 				ps.setTimestamp(paramIndex, new java.sql.Timestamp(cal.getTime().getTime()), cal);
 			}
 			else {
@@ -400,8 +396,7 @@ public abstract class StatementCreatorUtils {
 			else if (isDateValue(inValue.getClass())) {
 				ps.setTimestamp(paramIndex, new java.sql.Timestamp(((java.util.Date) inValue).getTime()));
 			}
-			else if (inValue instanceof Calendar) {
+			else if (inValue instanceof Calendar cal) {
-				Calendar cal = (Calendar) inValue;
 				ps.setTimestamp(paramIndex, new java.sql.Timestamp(cal.getTime().getTime()), cal);
 			}
 			else {

spring-jdbc/src/main/java/org/springframework/jdbc/core/metadata/GenericTableMetaDataProvider.java

@@ -56,7 +56,7 @@ public class GenericTableMetaDataProvider implements TableMetaDataProvider {
 
 	/** the name of the user currently connected. */
 	@Nullable
-	private String userName;
+	private final String userName;
 
 	/** indicates whether the identifiers are uppercased. */
 	private boolean storesUpperCaseIdentifiers = true;
@@ -71,11 +71,11 @@ public class GenericTableMetaDataProvider implements TableMetaDataProvider {
 	private boolean generatedKeysColumnNameArraySupported = true;
 
 	/** database products we know not supporting the use of a String[] for generated keys. */
-	private List<String> productsNotSupportingGeneratedKeysColumnNameArray =
+	private final List<String> productsNotSupportingGeneratedKeysColumnNameArray =
 			Arrays.asList("Apache Derby", "HSQL Database Engine");
 
 	/** Collection of TableParameterMetaData objects. */
-	private List<TableParameterMetaData> tableParameterMetaData = new ArrayList<>();
+	private final List<TableParameterMetaData> tableParameterMetaData = new ArrayList<>();
 
 
 	/**

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterUtils.java

@@ -293,8 +293,7 @@ public abstract class NamedParameterUtils {
 						}
 						k++;
 						Object entryItem = entryIter.next();
-						if (entryItem instanceof Object[]) {
+						if (entryItem instanceof Object[] expressionList) {
-							Object[] expressionList = (Object[]) entryItem;
 							actualSql.append('(');
 							for (int m = 0; m < expressionList.length; m++) {
 								if (m > 0) {

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/DataSourceUtils.java

@@ -474,7 +474,7 @@ public abstract class DataSourceUtils {
 
 		private final DataSource dataSource;
 
-		private int order;
+		private final int order;
 
 		private boolean holderActive = true;
 

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -185,8 +185,7 @@ public class EmbeddedDatabaseFactory {
 		this.dataSource = this.dataSourceFactory.getDataSource();
 
 		if (logger.isInfoEnabled()) {
-			if (this.dataSource instanceof SimpleDriverDataSource) {
+			if (this.dataSource instanceof SimpleDriverDataSource simpleDriverDataSource) {
-				SimpleDriverDataSource simpleDriverDataSource = (SimpleDriverDataSource) this.dataSource;
 				logger.info(String.format("Starting embedded database: url='%s', username='%s'",
 						simpleDriverDataSource.getUrl(), simpleDriverDataSource.getUsername()));
 			}

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/lookup/IsolationLevelDataSourceRouter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -106,8 +106,7 @@ public class IsolationLevelDataSourceRouter extends AbstractRoutingDataSource {
 		if (lookupKey instanceof Integer) {
 			return lookupKey;
 		}
-		else if (lookupKey instanceof String) {
+		else if (lookupKey instanceof String constantName) {
-			String constantName = (String) lookupKey;
 			if (!constantName.startsWith(DefaultTransactionDefinition.PREFIX_ISOLATION)) {
 				throw new IllegalArgumentException("Only isolation constants allowed");
 			}

spring-jdbc/src/main/java/org/springframework/jdbc/support/JdbcUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -285,12 +285,10 @@ public abstract class JdbcUtils {
 		if (obj != null) {
 			className = obj.getClass().getName();
 		}
-		if (obj instanceof Blob) {
+		if (obj instanceof Blob blob) {
-			Blob blob = (Blob) obj;
 			obj = blob.getBytes(1, (int) blob.length());
 		}
-		else if (obj instanceof Clob) {
+		else if (obj instanceof Clob clob) {
-			Clob clob = (Clob) obj;
 			obj = clob.getSubString(1, (int) clob.length());
 		}
 		else if ("oracle.sql.TIMESTAMP".equals(className) || "oracle.sql.TIMESTAMPTZ".equals(className)) {

spring-jdbc/src/main/java/org/springframework/jdbc/support/lob/PassThroughBlob.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,7 +40,7 @@ class PassThroughBlob implements Blob {
 	@Nullable
 	private InputStream binaryStream;
 
-	private long contentLength;
+	private final long contentLength;
 
 
 	public PassThroughBlob(byte[] content) {

spring-jdbc/src/main/java/org/springframework/jdbc/support/lob/PassThroughClob.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -50,7 +50,7 @@ class PassThroughClob implements Clob {
 	@Nullable
 	private InputStream asciiStream;
 
-	private long contentLength;
+	private final long contentLength;
 
 
 	public PassThroughClob(String content) {