[ci] Add final where appropriate per open rewrite

relaxed some of its suggestions but generally took most.

Author: hazendaz

src/main/java/org/apache/ibatis/datasource/unpooled/UnpooledDataSource.java

@@ -40,7 +40,7 @@ public class UnpooledDataSource implements DataSource {
 
   private ClassLoader driverClassLoader;
   private Properties driverProperties;
-  private static Map<String, Driver> registeredDrivers = new ConcurrentHashMap<>();
+  private static final Map<String, Driver> registeredDrivers = new ConcurrentHashMap<>();
 
   private String driver;
   private String url;
@@ -263,7 +263,7 @@ private void configureConnection(Connection conn) throws SQLException {
   }
 
   private static class DriverProxy implements Driver {
-    private Driver driver;
+    private final Driver driver;
 
     DriverProxy(Driver d) {
       this.driver = d;

src/main/java/org/apache/ibatis/executor/loader/ResultLoaderMap.java

@@ -134,7 +134,7 @@ public static class LoadPair implements Serializable {
     /**
      * Name of the unread property.
      */
-    private String property;
+    private final String property;
     /**
      * ID of SQL statement which loads the property.
      */

src/main/java/org/apache/ibatis/io/ResolverUtil.java

@@ -87,7 +87,7 @@ public interface Test {
   public static class IsA implements Test {
 
     /** The parent. */
-    private Class<?> parent;
+    private final Class<?> parent;
 
     /**
      * Constructs an IsA test using the supplied Class as the parent class/interface.
@@ -118,7 +118,7 @@ public String toString() {
   public static class AnnotatedWith implements Test {
 
     /** The annotation. */
-    private Class<? extends Annotation> annotation;
+    private final Class<? extends Annotation> annotation;
 
     /**
      * Constructs an AnnotatedWith test for the specified annotation type.

src/main/java/org/apache/ibatis/io/Resources.java

@@ -32,7 +32,7 @@
  */
 public class Resources {
 
-  private static ClassLoaderWrapper classLoaderWrapper = new ClassLoaderWrapper();
+  private static final ClassLoaderWrapper classLoaderWrapper = new ClassLoaderWrapper();
 
   /**
    * Charset to use when calling getResourceAsReader. null means use the system default.

src/main/java/org/apache/ibatis/mapping/Discriminator.java

@@ -32,7 +32,7 @@ public class Discriminator {
   }
 
   public static class Builder {
-    private Discriminator discriminator = new Discriminator();
+    private final Discriminator discriminator = new Discriminator();
 
     public Builder(Configuration configuration, ResultMapping resultMapping, Map<String, String> discriminatorMap) {
       discriminator.resultMapping = resultMapping;

src/main/java/org/apache/ibatis/mapping/MappedStatement.java

@@ -63,7 +63,7 @@ public final class MappedStatement {
   }
 
   public static class Builder {
-    private MappedStatement mappedStatement = new MappedStatement();
+    private final MappedStatement mappedStatement = new MappedStatement();
 
     public Builder(Configuration configuration, String id, SqlSource sqlSource, SqlCommandType sqlCommandType) {
       mappedStatement.configuration = configuration;

src/main/java/org/apache/ibatis/mapping/ParameterMap.java

@@ -33,7 +33,7 @@ private ParameterMap() {
   }
 
   public static class Builder {
-    private ParameterMap parameterMap = new ParameterMap();
+    private final ParameterMap parameterMap = new ParameterMap();
 
     public Builder(Configuration configuration, String id, Class<?> type, List<ParameterMapping> parameterMappings) {
       parameterMap.id = id;

src/main/java/org/apache/ibatis/mapping/ParameterMapping.java

@@ -43,7 +43,7 @@ private ParameterMapping() {
   }
 
   public static class Builder {
-    private ParameterMapping parameterMapping = new ParameterMapping();
+    private final ParameterMapping parameterMapping = new ParameterMapping();
 
     public Builder(Configuration configuration, String property, TypeHandler<?> typeHandler) {
       parameterMapping.configuration = configuration;

src/main/java/org/apache/ibatis/mapping/ResultMap.java

@@ -56,7 +56,7 @@ private ResultMap() {
   public static class Builder {
     private static final Log log = LogFactory.getLog(Builder.class);
 
-    private ResultMap resultMap = new ResultMap();
+    private final ResultMap resultMap = new ResultMap();
 
     public Builder(Configuration configuration, String id, Class<?> type, List<ResultMapping> resultMappings) {
       this(configuration, id, type, resultMappings, null);

src/main/java/org/apache/ibatis/mapping/ResultMapping.java

@@ -50,7 +50,7 @@ public class ResultMapping {
   }
 
   public static class Builder {
-    private ResultMapping resultMapping = new ResultMapping();
+    private final ResultMapping resultMapping = new ResultMapping();
 
     public Builder(Configuration configuration, String property, String column, TypeHandler<?> typeHandler) {
       this(configuration, property);