BAEL-4290: tracking down cause of Spring's “not eligible for auto-proxying” (#10593)

spring-core-5/pom.xml

@@ -25,6 +25,11 @@
             <version>${spring-boot-starter.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+        </dependency>
     </dependencies>
 
     <build>

spring-core-5/src/main/java/com/baeldung/component/autoproxying/DataCache.java

@@ -0,0 +1,12 @@
+package com.baeldung.component.autoproxying;
+
+import lombok.Getter;
+import org.springframework.stereotype.Component;
+
+@Getter
+@Component
+public class DataCache {
+    @RandomInt(min = 2, max = 10)
+    private int group;
+    private String name;
+}

spring-core-5/src/main/java/com/baeldung/component/autoproxying/EligibleForAutoProxyRandomIntProcessor.java

@@ -0,0 +1,33 @@
+package com.baeldung.component.autoproxying;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.annotation.Lazy;
+import org.springframework.util.ReflectionUtils;
+
+import java.lang.reflect.Field;
+
+public class EligibleForAutoProxyRandomIntProcessor implements BeanPostProcessor {
+    private final RandomIntGenerator randomIntGenerator;
+
+    @Lazy
+    public EligibleForAutoProxyRandomIntProcessor(RandomIntGenerator randomIntGenerator) {
+        this.randomIntGenerator = randomIntGenerator;
+    }
+
+    @Override
+    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+        Field[] fields = bean.getClass().getDeclaredFields();
+        for (Field field : fields) {
+            RandomInt injectRandomInt = field.getAnnotation(RandomInt.class);
+            if (injectRandomInt != null) {
+                int min = injectRandomInt.min();
+                int max = injectRandomInt.max();
+                int randomValue = randomIntGenerator.generate(min, max);
+                field.setAccessible(true);
+                ReflectionUtils.setField(field, bean, randomValue);
+            }
+        }
+        return bean;
+    }
+}

spring-core-5/src/main/java/com/baeldung/component/autoproxying/NotEligibleForAutoProxyRandomIntProcessor.java

@@ -0,0 +1,31 @@
+package com.baeldung.component.autoproxying;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.util.ReflectionUtils;
+
+import java.lang.reflect.Field;
+
+public class NotEligibleForAutoProxyRandomIntProcessor implements BeanPostProcessor {
+    private final RandomIntGenerator randomIntGenerator;
+
+    public NotEligibleForAutoProxyRandomIntProcessor(RandomIntGenerator randomIntGenerator) {
+        this.randomIntGenerator = randomIntGenerator;
+    }
+
+    @Override
+    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+        Field[] fields = bean.getClass().getDeclaredFields();
+        for (Field field : fields) {
+            RandomInt injectRandomInt = field.getAnnotation(RandomInt.class);
+            if (injectRandomInt != null) {
+                int min = injectRandomInt.min();
+                int max = injectRandomInt.max();
+                int randomValue = randomIntGenerator.generate(min, max);
+                field.setAccessible(true);
+                ReflectionUtils.setField(field, bean, randomValue);
+            }
+        }
+        return bean;
+    }
+}

spring-core-5/src/main/java/com/baeldung/component/autoproxying/RandomInt.java

@@ -0,0 +1,11 @@
+package com.baeldung.component.autoproxying;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface RandomInt {
+    int min();
+
+    int max();
+}

spring-core-5/src/main/java/com/baeldung/component/autoproxying/RandomIntGenerator.java

@@ -0,0 +1,21 @@
+package com.baeldung.component.autoproxying;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+
+import java.util.Random;
+
+@Slf4j
+@Component
+public class RandomIntGenerator {
+    private final Random random = new Random();
+    private final DataCache dataCache;
+
+    public RandomIntGenerator(DataCache dataCache) {
+        this.dataCache = dataCache;
+    }
+
+    public int generate(int min, int max) {
+        return random.nextInt(max - min) + min;
+    }
+}

spring-core-5/src/test/java/com/baeldung/component/autoproxying/EligibleForAutoProxyingIntegrationTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.component.autoproxying;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = {EligibleForAutoProxyRandomIntProcessor.class, DataCache.class, RandomIntGenerator.class})
+public class EligibleForAutoProxyingIntegrationTest {
+    private static MemoryLogAppender memoryAppender;
+
+    private EligibleForAutoProxyRandomIntProcessor randomIntProcessor;
+
+    @Autowired
+    private DataCache dataCache;
+
+    @BeforeClass
+    public static void setup() {
+        memoryAppender = new MemoryLogAppender();
+        memoryAppender.setContext((LoggerContext) LoggerFactory.getILoggerFactory());
+
+        Logger logger = (Logger) LoggerFactory.getLogger("org.springframework.context");
+        logger.setLevel(Level.INFO);
+        logger.addAppender(memoryAppender);
+        memoryAppender.start();
+    }
+
+    @Test
+    public void givenAutowireInBeanPostProcessor_whenSpringContextInitialize_thenNotEligibleLogShouldShowAndGroupFieldPopulated() {
+        List<ILoggingEvent> notEligibleEvents = memoryAppender.search("Bean 'randomIntGenerator' of type [com.baeldung.autoproxying.RandomIntGenerator] " +
+          "is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)");
+
+        assertEquals(0, notEligibleEvents.size());
+        assertNotEquals(0, dataCache.getGroup());
+    }
+}

spring-core-5/src/test/java/com/baeldung/component/autoproxying/MemoryLogAppender.java

@@ -0,0 +1,48 @@
+package com.baeldung.component.autoproxying;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.read.ListAppender;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class MemoryLogAppender extends ListAppender<ILoggingEvent> {
+    public void reset() {
+        this.list.clear();
+    }
+
+    public boolean contains(String string, Level level) {
+        return this.list.stream()
+          .anyMatch(event -> event.getMessage().toString().contains(string)
+            && event.getLevel().equals(level));
+    }
+
+    public int countEventsForLogger(String loggerName) {
+        return (int) this.list.stream()
+          .filter(event -> event.getLoggerName().contains(loggerName))
+          .count();
+    }
+
+    public List<ILoggingEvent> search(String string) {
+        return this.list.stream()
+          .filter(event -> event.getMessage().toString().contains(string))
+          .collect(Collectors.toList());
+    }
+
+    public List<ILoggingEvent> search(String string, Level level) {
+        return this.list.stream()
+          .filter(event -> event.getMessage().toString().contains(string)
+            && event.getLevel().equals(level))
+          .collect(Collectors.toList());
+    }
+
+    public int getSize() {
+        return this.list.size();
+    }
+
+    public List<ILoggingEvent> getLoggedEvents() {
+        return Collections.unmodifiableList(this.list);
+    }
+}

spring-core-5/src/test/java/com/baeldung/component/autoproxying/NotEligibleForAutoProxyingIntegrationTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.component.autoproxying;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = {NotEligibleForAutoProxyRandomIntProcessor.class, DataCache.class, RandomIntGenerator.class})
+public class NotEligibleForAutoProxyingIntegrationTest {
+    private static MemoryLogAppender memoryAppender;
+
+    private NotEligibleForAutoProxyRandomIntProcessor proxyRandomIntProcessor;
+
+    @Autowired
+    private DataCache dataCache;
+
+    @BeforeClass
+    public static void setup() {
+        memoryAppender = new MemoryLogAppender();
+        memoryAppender.setContext((LoggerContext) LoggerFactory.getILoggerFactory());
+
+        Logger logger = (Logger) LoggerFactory.getLogger("org.springframework.context");
+        logger.setLevel(Level.INFO);
+        logger.addAppender(memoryAppender);
+        memoryAppender.start();
+    }
+
+    @Test
+    public void givenAutowireInBeanPostProcessor_whenSpringContextInitialize_thenNotEligibleLogShouldShowAndGroupFieldNotPopulated() {
+        List<ILoggingEvent> notEligibleEvents = memoryAppender.search("Bean 'randomIntGenerator' of type [com.baeldung.autoproxying.RandomIntGenerator] " +
+          "is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)");
+
+        assertEquals(1, notEligibleEvents.size());
+        assertEquals(0, dataCache.getGroup());
+    }
+}