Code review feedback - rename toOptionalInstance -> toInstance (with a boolean param)

Author: onobc

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/PropertyMapper.java

@@ -24,6 +24,7 @@
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 import org.springframework.util.function.SingletonSupplier;
@@ -302,27 +303,31 @@ public void to(Consumer<T> consumer) {
 		 * @throws NoSuchElementException if the value has been filtered
 		 */
 		public <R> R toInstance(Function<T, R> factory) {
-			Assert.notNull(factory, "Factory must not be null");
-			T value = this.supplier.get();
-			if (!this.predicate.test(value)) {
-				throw new NoSuchElementException("No value present");
-			}
-			return factory.apply(value);
+			return toInstance(factory, true);
 		}
 
 		/**
-		 * Complete the mapping by creating a new instance
+		 * Complete the mapping by creating a new instance from the non-filtered value.
 		 * @param <R> the resulting type
 		 * @param factory the factory used to create the instance
-		 * @return the created instance or empty when the value is filtered
+		 * @param failIfFiltered whether to throw exception or return {@code null} if the
+		 * value has been filtered
+		 * @return the instance or {@code null} if the value has been filtered and
+		 * {@code failIfFiltered} is {@code false}
+		 * @throws NoSuchElementException if the value has been filtered and
+		 * {@code failIfFiltered} is {@code true}
 		 */
-		public <R> Optional<R> toOptionalInstance(Function<T, R> factory) {
+		@Nullable
+		public <R> R toInstance(Function<T, R> factory, boolean failIfFiltered) {
 			Assert.notNull(factory, "Factory must not be null");
 			T value = this.supplier.get();
 			if (!this.predicate.test(value)) {
-				return Optional.empty();
+				if (failIfFiltered) {
+					throw new NoSuchElementException("No value present");
+				}
+				return null;
 			}
-			return Optional.ofNullable(factory.apply(value));
+			return factory.apply(value);
 		}
 
 		/**

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/PropertyMapperTests.java

@@ -16,7 +16,6 @@
 
 package org.springframework.boot.context.properties;
 
-import java.util.Optional;
 import java.util.function.Supplier;
 
 import org.junit.jupiter.api.Assertions;
@@ -210,21 +209,21 @@ void whenWhenValueMatchesShouldSupportChainedCalls() {
 	}
 
 	@Test
-	void toOptionalInstanceWithNonFilteredValueShouldReturnFactoryValue() {
-		Optional<String> result = this.map.from("123").whenEqualTo("123").toOptionalInstance(String::new);
-		assertThat(result).isNotEmpty().hasValue("123");
+	void toInstanceWithoutFailFlagWithNonFilteredValueShouldReturnFactoryValue() {
+		String result = this.map.from("123").whenEqualTo("123").toInstance(String::new, false);
+		assertThat(result).isEqualTo("123");
 	}
 
 	@Test
-	void toOptionalInstanceWithNonFilteredValueShouldTolerateNullFactoryValue() {
-		Optional<String> result = this.map.from("123").whenEqualTo("123").toOptionalInstance((s) -> null);
-		assertThat(result).isEmpty();
+	void toInstanceWithoutFailFlagWithNonFilteredValueShouldTolerateNullFactoryValue() {
+		String result = this.map.from("123").whenEqualTo("123").toInstance((s) -> null, false);
+		assertThat(result).isNull();
 	}
 
 	@Test
-	void toOptionalInstanceWithFilteredValueShouldReturnEmpty() {
-		Optional<String> result = this.map.from("123").whenEqualTo("foo").toOptionalInstance(String::new);
-		assertThat(result).isEmpty();
+	void toInstanceWithoutFailFlagWithFilteredValueShouldReturnNull() {
+		String result = this.map.from("123").whenEqualTo("foo").toInstance(String::new, false);
+		assertThat(result).isNull();
 	}
 
 	static class Count<T> implements Supplier<T> {