Add getRequiredName and hasName API to org.springframework.data.mapping.Parameter.

Introduces a more convenient API to simplify the caller side especially for conditionals that want to determine whether a parameter name is present.

Closes #3088
Original pull request: #3272

src/main/java/org/springframework/data/mapping/Parameter.java

@@ -33,6 +33,7 @@ import org.springframework.util.StringUtils;
  * @param <T> the type of the parameter
  * @author Oliver Gierke
  * @author Christoph Strobl
+ * @author Chris Bono
  */
 public class Parameter<T, P extends PersistentProperty<P>> {
 
@@ -99,6 +100,31 @@ public class Parameter<T, P extends PersistentProperty<P>> {
 		return name;
 	}
 
+	/**
+	 * Returns the required parameter name.
+	 *
+	 * @return the parameter name or throws {@link IllegalStateException} if the parameter does not have a name
+	 * @since 3.5
+	 */
+	public String getRequiredName() {
+
+		if (!hasName()) {
+			throw new IllegalStateException("No name associated with this parameter");
+		}
+
+		return getName();
+	}
+
+	/**
+	 * Returns whether the parameter has a name.
+	 *
+	 * @return whether the parameter has a name
+	 * @since 3.5
+	 */
+	public boolean hasName() {
+		return this.name != null;
+	}
+
 	/**
 	 * Returns the {@link TypeInformation} of the parameter.
 	 *

src/test/java/org/springframework/data/mapping/ParameterUnitTests.java

@@ -37,6 +37,7 @@ import org.springframework.data.util.TypeInformation;
  *
  * @author Oliver Gierke
  * @author Christoph Strobl
+ * @author Chris Bono
  */
 @ExtendWith(MockitoExtension.class)
 class ParameterUnitTests<P extends PersistentProperty<P>> {
@@ -149,6 +150,35 @@ class ParameterUnitTests<P extends PersistentProperty<P>> {
 		assertThat(iFace.isEnclosingClassParameter()).isFalse();
 	}
 
+	@Test // GH-3088
+	void getRequiredNameDoesNotThrowExceptionWhenHasName() {
+
+		var parameter = new Parameter<>("someName", type, annotations, entity);
+		assertThat(parameter.getRequiredName()).isEqualTo("someName");
+	}
+
+	@Test // GH-3088
+	void getRequiredNameThrowsExceptionWhenHasNoName() {
+
+		var parameter = new Parameter<>(null, type, annotations, entity);
+		assertThatIllegalStateException().isThrownBy(() -> parameter.getRequiredName())
+				.withMessage("No name associated with this parameter");
+	}
+
+	@Test // GH-3088
+	void hasNameReturnsTrueWhenHasName() {
+
+		var parameter = new Parameter<>("someName", type, annotations, entity);
+		assertThat(parameter.hasName()).isTrue();
+	}
+
+	@Test // GH-3088
+	void hasNameReturnsFalseWhenHasNoName() {
+
+		var parameter = new Parameter<>(null, type, annotations, entity);
+		assertThat(parameter.hasName()).isFalse();
+	}
+
 	interface IFace {
 
 		record RecordMember(IFace iFace) {