Polishing.

Original pull request #1894

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/dialect/OracleDialect.java

@@ -53,7 +53,7 @@ public class OracleDialect extends org.springframework.data.relational.core.dial
 			}
 		}
 
-		if (builder.length() == 0) {
+		if (builder.isEmpty()) {
 			return "";
 		}
 

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/dialect/SqlServerDialect.java

@@ -50,7 +50,7 @@ public class SqlServerDialect extends org.springframework.data.relational.core.d
 			}
 		}
 
-		if (builder.length() == 0) {
+		if (builder.isEmpty()) {
 			return "";
 		}
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/AbstractDialect.java

@@ -196,7 +196,7 @@ public abstract class AbstractDialect implements Dialect {
 		@Override
 		public CharSequence apply(CharSequence charSequence) {
 
-			if (charSequence.length() == 0) {
+			if (charSequence.isEmpty()) {
 				return charSequence;
 			}
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/InVisitor.java

@@ -47,7 +47,7 @@ class InVisitor extends TypedSingleConditionRenderSupport<In> {
 				part.append(", ");
 			}
 
-			if (part.length() == 0) {
+			if (part.isEmpty()) {
 				part.append(renderedPart);
 				if (notIn) {
 					part.append(" NOT");