AOT contribution for @PersistenceContext and @PersistenceUnit

Closes gh-28364

spring-beans/src/main/java/org/springframework/beans/factory/generator/BeanFieldGenerator.java

@@ -0,0 +1,65 @@
+/*
+ * 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.beans.factory.generator;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+import org.springframework.aot.generator.ProtectedAccess.Options;
+import org.springframework.javapoet.CodeBlock;
+import org.springframework.javapoet.support.MultiStatement;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * Support for generating {@link Field} access.
+ *
+ * @author Stephane Nicoll
+ * @since 6.0
+ */
+public class BeanFieldGenerator {
+
+	/**
+	 * The {@link Options} to use to access a field.
+	 */
+	public static final Options FIELD_OPTIONS = Options.defaults()
+			.useReflection(member -> Modifier.isPrivate(member.getModifiers())).build();
+
+
+	/**
+	 * Generate the necessary code to set the specified field. Use reflection
+	 * using {@link ReflectionUtils} if necessary.
+	 * @param field the field to set
+	 * @param value a code representation of the field value
+	 * @return the code to set the specified field
+	 */
+	public MultiStatement generateSetValue(String target, Field field, CodeBlock value) {
+		MultiStatement statement = new MultiStatement();
+		boolean useReflection = Modifier.isPrivate(field.getModifiers());
+		if (useReflection) {
+			String fieldName = String.format("%sField", field.getName());
+			statement.addStatement("$T $L = $T.findField($T.class, $S)", Field.class, fieldName, ReflectionUtils.class,
+					field.getDeclaringClass(), field.getName());
+			statement.addStatement("$T.makeAccessible($L)", ReflectionUtils.class, fieldName);
+			statement.addStatement("$T.setField($L, $L, $L)", ReflectionUtils.class, fieldName, target, value);
+		}
+		else {
+			statement.addStatement("$L.$L = $L", target, field.getName(), value);
+		}
+		return statement;
+	}
+
+}

spring-beans/src/main/java/org/springframework/beans/factory/generator/InjectionGenerator.java

@@ -34,7 +34,6 @@
 import org.springframework.javapoet.CodeBlock;
 import org.springframework.javapoet.CodeBlock.Builder;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.ReflectionUtils;
 
 /**
  * Generate the necessary code to {@link #generateInstantiation(Executable)
@@ -53,14 +52,13 @@
  */
 public class InjectionGenerator {
 
-	private static final Options FIELD_INJECTION_OPTIONS = Options.defaults()
-			.useReflection(member -> Modifier.isPrivate(member.getModifiers())).build();
-
 	private static final Options METHOD_INJECTION_OPTIONS = Options.defaults()
 			.useReflection(member -> false).build();
 
 	private final BeanParameterGenerator parameterGenerator = new BeanParameterGenerator();
 
+	private final BeanFieldGenerator fieldGenerator = new BeanFieldGenerator();
+
 
 	/**
 	 * Generate the necessary code to instantiate an object using the specified
@@ -110,7 +108,7 @@ public Options getProtectedAccessInjectionOptions(Member member) {
 			return METHOD_INJECTION_OPTIONS;
 		}
 		if (member instanceof Field) {
-			return FIELD_INJECTION_OPTIONS;
+			return BeanFieldGenerator.FIELD_OPTIONS;
 		}
 		throw new IllegalArgumentException("Could not handle member " + member);
 	}
@@ -230,24 +228,13 @@ CodeBlock generateFieldInjection(Field injectionPoint, boolean required) {
 		code.add("instanceContext.field($S", injectionPoint.getName());
 		code.add(")\n").indent().indent();
 		if (required) {
-			code.add(".invoke(beanFactory, (attributes) ->");
-		}
-		else {
-			code.add(".resolve(beanFactory, false).ifResolved((attributes) ->");
-		}
-		boolean hasAssignment = Modifier.isPrivate(injectionPoint.getModifiers());
-		if (hasAssignment) {
-			code.beginControlFlow("");
-			String fieldName = String.format("%sField", injectionPoint.getName());
-			code.addStatement("$T $L = $T.findField($T.class, $S)", Field.class, fieldName, ReflectionUtils.class,
-					injectionPoint.getDeclaringClass(), injectionPoint.getName());
-			code.addStatement("$T.makeAccessible($L)", ReflectionUtils.class, fieldName);
-			code.addStatement("$T.setField($L, bean, attributes.get(0))", ReflectionUtils.class, fieldName);
-			code.unindent().add("}");
+			code.add(".invoke(beanFactory, ");
 		}
 		else {
-			code.add(" bean.$L = attributes.get(0)", injectionPoint.getName());
+			code.add(".resolve(beanFactory, false).ifResolved(");
 		}
+		code.add(this.fieldGenerator.generateSetValue("bean", injectionPoint,
+				CodeBlock.of("attributes.get(0)")).toLambdaBody("(attributes) ->"));
 		code.add(")").unindent().unindent();
 		return code.build();
 	}

spring-beans/src/test/java/org/springframework/beans/factory/generator/BeanFieldGeneratorTests.java

@@ -0,0 +1,78 @@
+/*
+ * 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.beans.factory.generator;
+
+import java.lang.reflect.Field;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.javapoet.CodeBlock;
+import org.springframework.javapoet.support.CodeSnippet;
+import org.springframework.javapoet.support.MultiStatement;
+import org.springframework.util.ReflectionUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link BeanFieldGenerator}.
+ *
+ * @author Stephane Nicoll
+ */
+class BeanFieldGeneratorTests {
+
+	private final BeanFieldGenerator generator = new BeanFieldGenerator();
+
+	@Test
+	void generateSetFieldWithPublicField() {
+		MultiStatement statement = this.generator.generateSetValue("bean",
+				field(SampleBean.class, "one"), CodeBlock.of("$S", "test"));
+		assertThat(CodeSnippet.process(statement.toCodeBlock())).isEqualTo("""
+				bean.one = "test";
+				""");
+	}
+
+	@Test
+	void generateSetFieldWithPrivateField() {
+		MultiStatement statement = this.generator.generateSetValue("example",
+				field(SampleBean.class, "two"), CodeBlock.of("42"));
+		CodeSnippet code = CodeSnippet.of(statement.toCodeBlock());
+		assertThat(code.getSnippet()).isEqualTo("""
+				Field twoField = ReflectionUtils.findField(BeanFieldGeneratorTests.SampleBean.class, "two");
+				ReflectionUtils.makeAccessible(twoField);
+				ReflectionUtils.setField(twoField, example, 42);
+				""");
+		assertThat(code.hasImport(ReflectionUtils.class)).isTrue();
+		assertThat(code.hasImport(BeanFieldGeneratorTests.class)).isTrue();
+	}
+
+
+	private Field field(Class<?> type, String name) {
+		Field field = ReflectionUtils.findField(type, name);
+		assertThat(field).isNotNull();
+		return field;
+	}
+
+
+	public static class SampleBean {
+
+		public String one;
+
+		private int two;
+
+	}
+
+}

spring-core/src/main/java/org/springframework/javapoet/support/MultiStatement.java

@@ -44,6 +44,16 @@ public boolean isEmpty() {
 		return this.statements.isEmpty();
 	}
 
+	/**
+	 * Add the statements defined in the specified multi statement to this instance.
+	 * @param multiStatement the statements to add
+	 * @return {@code this}, to facilitate method chaining
+	 */
+	public MultiStatement add(MultiStatement multiStatement) {
+		this.statements.addAll(multiStatement.statements);
+		return this;
+	}
+
 	/**
 	 * Add the specified {@link CodeBlock codeblock} rendered as-is.
 	 * @param codeBlock the code block to add

spring-core/src/test/java/org/springframework/javapoet/support/MultiStatementTests.java

@@ -150,4 +150,17 @@ void multiStatementsWithAddAllAndLambda() {
 				"}");
 	}
 
+	@Test
+	void addWithAnotherMultiStatement() {
+		MultiStatement statements = new MultiStatement();
+		statements.addStatement(CodeBlock.of("test.invoke()"));
+		MultiStatement another = new MultiStatement();
+		another.addStatement(CodeBlock.of("test.another()"));
+		statements.add(another);
+		assertThat(statements.toCodeBlock().toString()).isEqualTo("""
+				test.invoke();
+				test.another();
+				""");
+	}
+
 }

spring-orm/spring-orm.gradle

@@ -11,6 +11,7 @@ dependencies {
 	optional("org.eclipse.persistence:org.eclipse.persistence.jpa")
 	optional("org.hibernate:hibernate-core-jakarta")
 	optional("jakarta.servlet:jakarta.servlet-api")
+	testImplementation(project(":spring-core-test"))
 	testImplementation(testFixtures(project(":spring-beans")))
 	testImplementation(testFixtures(project(":spring-context")))
 	testImplementation(testFixtures(project(":spring-core")))