Introduce builder API for AOT processor Settings

Closes gh-29341

spring-context/src/test/java/org/springframework/context/aot/AotProcessorTests.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2002-2022 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.aot;
+
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.context.aot.AbstractAotProcessor.Settings;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
+/**
+ * Tests for {@link AbstractAotProcessor}, settings, and builder.
+ *
+ * @author Sam Brannen
+ * @since 6.0
+ */
+class AotProcessorTests {
+
+	@Test
+	void builderRejectsMissingSourceOutput() {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder().build())
+			.withMessageContaining("'sourceOutput'");
+	}
+
+	@Test
+	void builderRejectsMissingResourceOutput(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder().sourceOutput(tempDir).build())
+			.withMessageContaining("'resourceOutput'");
+	}
+
+	@Test
+	void builderRejectsMissingClassOutput(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.build())
+			.withMessageContaining("'classOutput'");
+	}
+
+	@Test
+	void builderRejectsMissingGroupdId(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.classOutput(tempDir)
+				.build())
+			.withMessageContaining("'groupId'");
+	}
+
+	@Test
+	void builderRejectsEmptyGroupdId(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.classOutput(tempDir)
+				.groupId("           ")
+				.build())
+			.withMessageContaining("'groupId'");
+	}
+
+	@Test
+	void builderRejectsMissingArtifactId(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.classOutput(tempDir)
+				.groupId("my-group")
+				.build())
+			.withMessageContaining("'artifactId'");
+	}
+
+	@Test
+	void builderRejectsEmptyArtifactId(@TempDir Path tempDir) {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.classOutput(tempDir)
+				.groupId("my-group")
+				.artifactId("           ")
+				.build())
+			.withMessageContaining("'artifactId'");
+	}
+
+	@Test
+	void builderAcceptsRequiredSettings(@TempDir Path tempDir) {
+		Settings settings = Settings.builder()
+				.sourceOutput(tempDir)
+				.resourceOutput(tempDir)
+				.classOutput(tempDir)
+				.groupId("my-group")
+				.artifactId("my-artifact")
+				.build();
+		assertThat(settings).isNotNull();
+		assertThat(settings.getSourceOutput()).isEqualTo(tempDir);
+		assertThat(settings.getResourceOutput()).isEqualTo(tempDir);
+		assertThat(settings.getClassOutput()).isEqualTo(tempDir);
+		assertThat(settings.getGroupId()).isEqualTo("my-group");
+		assertThat(settings.getArtifactId()).isEqualTo("my-artifact");
+	}
+
+}

spring-context/src/test/java/org/springframework/context/aot/ContextAotProcessorTests.java

@@ -128,12 +128,13 @@ class ContextAotProcessorTests {
 
 		private static Settings createSettings(Path sourceOutput, Path resourceOutput,
 				Path classOutput, String groupId, String artifactId) {
-			return new Settings()
-					.setSourceOutput(sourceOutput)
-					.setResourceOutput(resourceOutput)
-					.setClassOutput(classOutput)
-					.setArtifactId(artifactId)
-					.setGroupId(groupId);
+			return Settings.builder()
+					.sourceOutput(sourceOutput)
+					.resourceOutput(resourceOutput)
+					.classOutput(classOutput)
+					.artifactId(artifactId)
+					.groupId(groupId)
+					.build();
 		}
 
 		@Override