BAEL-5451 Code for the Finding All Beans with a Custom Annotation article (#12143)

spring-di-3/src/main/java/com/baeldung/countingbeans/latestsspring/MyComponent.java

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+package com.baeldung.countingbeans.latestsspring;
+
+import org.springframework.stereotype.Component;
+
+@Component
+@MyCustomAnnotation
+public class MyComponent {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/latestsspring/MyConfigurationBean.java

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+package com.baeldung.countingbeans.latestsspring;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class MyConfigurationBean {
+
+    @Bean
+    @MyCustomAnnotation
+    MyService myService() {
+        return new MyService();
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/latestsspring/MyCustomAnnotation.java

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+package com.baeldung.countingbeans.latestsspring;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention( RetentionPolicy.RUNTIME )
+public @interface MyCustomAnnotation {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/latestsspring/MyService.java

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+package com.baeldung.countingbeans.latestsspring;
+
+public class MyService {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/factorybeans/AnnotatedBeansComponent.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.stereotype.Component;
+
+@Component
+public class AnnotatedBeansComponent {
+
+    @Autowired
+    GenericApplicationContext applicationContext;
+
+    public List<String> getBeansWithAnnotation(Class<?> annotationClass) {
+        return BeanUtils.getBeansWithAnnotation(applicationContext, annotationClass);
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/factorybeans/BeanUtils.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+
+public class BeanUtils {
+
+    // NB : this method lists only beans created via factory methods
+    public static List<String> getBeansWithAnnotation(GenericApplicationContext applicationContext, Class<?> annotationClass) {
+        List<String> result = new ArrayList<String>();
+        ConfigurableListableBeanFactory factory = applicationContext.getBeanFactory();
+        for(String name : factory.getBeanDefinitionNames()) {
+            BeanDefinition bd = factory.getBeanDefinition(name);
+            if(bd.getSource() instanceof AnnotatedTypeMetadata) {
+                AnnotatedTypeMetadata metadata = (AnnotatedTypeMetadata) bd.getSource();
+                if (metadata.getAnnotationAttributes(annotationClass.getName()) != null) {
+                    result.add(name);
+                }
+            }
+        }
+        return result;
+    }
+
+    // NB : list beans created via factory methods using streams (same method as before, written differently)
+    public static List<String> getBeansWithAnnotation_StreamVersion(GenericApplicationContext applicationContext, Class<?> annotationClass) {
+        ConfigurableListableBeanFactory factory = applicationContext.getBeanFactory();
+        return Arrays.stream(factory.getBeanDefinitionNames())
+            .filter(name -> isAnnotated(factory, name, annotationClass))
+            .collect(Collectors.toList());
+    }
+
+    private static boolean isAnnotated(ConfigurableListableBeanFactory factory, String beanName, Class<?> clazz) {
+        BeanDefinition beanDefinition = factory.getBeanDefinition(beanName);
+        if(beanDefinition.getSource() instanceof AnnotatedTypeMetadata) {
+            AnnotatedTypeMetadata metadata = (AnnotatedTypeMetadata) beanDefinition.getSource();
+            return metadata.getAnnotationAttributes(clazz.getName()) != null;
+        }
+        return false;
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/factorybeans/MyConfigurationBean.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class MyConfigurationBean {
+
+    @Bean
+    @MyCustomAnnotation
+    MyService myService() {
+        return new MyService();
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/factorybeans/MyCustomAnnotation.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention( RetentionPolicy.RUNTIME )
+public @interface MyCustomAnnotation {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/factorybeans/MyService.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+public class MyService {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/qualifier/MyComponent.java

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+package com.baeldung.countingbeans.olderspring.qualifier;
+
+import org.springframework.stereotype.Component;
+
+@Component
+@MyCustomAnnotation
+public class MyComponent {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/qualifier/MyConfigurationBean.java

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+package com.baeldung.countingbeans.olderspring.qualifier;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class MyConfigurationBean {
+
+    @Bean
+    @MyCustomAnnotation
+    MyService myService() {
+        return new MyService();
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/qualifier/MyCustomAnnotation.java

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+package com.baeldung.countingbeans.olderspring.qualifier;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+
+@Retention( RetentionPolicy.RUNTIME )
+@Qualifier
+public @interface MyCustomAnnotation {
+
+}

spring-di-3/src/main/java/com/baeldung/countingbeans/olderspring/qualifier/MyService.java

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+package com.baeldung.countingbeans.olderspring.qualifier;
+
+public class MyService {
+
+}

spring-di-3/src/test/java/com/baeldung/countingbeans/latestsspring/AnnotatedBeansIntegrationTest.java

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+package com.baeldung.countingbeans.latestsspring;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Arrays;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+public class AnnotatedBeansIntegrationTest {
+
+    /**
+     * Note : this test fails with any spring version < 2.2
+     * Before, the getBeansWithAnnotation method was not checking the beans created via factory method
+     * Please find the change here : https://github.com/spring-projects/spring-framework/commit/e0fe32af05ac525ef5e11c3ac5195a08759bb85e
+     */
+    @Test
+    void whenApplicationContextStarted_ThenShouldDetectAllAnnotatedBeans() {
+        try (AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext( MyComponent.class, MyConfigurationBean.class )) {
+            Map<String,Object> beans = applicationContext.getBeansWithAnnotation(MyCustomAnnotation.class);
+            assertEquals(2, beans.size());
+            assertTrue(beans.keySet().containsAll(Arrays.asList("myComponent", "myService")));
+        }
+    }
+
+}

spring-di-3/src/test/java/com/baeldung/countingbeans/olderspring/factorybeans/AnnotatedBeansIntegrationTest.java

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+package com.baeldung.countingbeans.olderspring.factorybeans;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = {MyConfigurationBean.class, AnnotatedBeansComponent.class})
+public class AnnotatedBeansIntegrationTest {
+
+    @Autowired
+    AnnotatedBeansComponent annotatedBeansComponent;
+
+    @Test
+    void whenBeanUtilsGetBeansWithAnnotation_ThenShouldListAnnotatedBean() {
+        try (AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MyConfigurationBean.class)) {
+            List<String> result = BeanUtils.getBeansWithAnnotation(applicationContext, MyCustomAnnotation.class);
+            assertEquals(1, result.size());
+            assertEquals("myService", result.get(0));
+        }
+    }
+
+    @Test
+    void whenBeanUtilsGetBeansWithAnnotationStreamVersion_ThenShouldListAnnotatedBean() {
+        try (AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MyConfigurationBean.class)) {
+            List<String> result = BeanUtils.getBeansWithAnnotation(applicationContext, MyCustomAnnotation.class);
+            assertEquals(1, result.size());
+            assertEquals("myService", result.get(0));
+
+        }
+    }
+
+    @Test
+    void whenAnnotatedBeansComponentGetBeansWithAnnotation_ThenShouldListAnnotatedBean() {
+        List<String> result = annotatedBeansComponent.getBeansWithAnnotation(MyCustomAnnotation.class);
+        assertEquals(1, result.size());
+        assertEquals("myService", result.get(0));
+    }
+
+}

spring-di-3/src/test/java/com/baeldung/countingbeans/olderspring/qualifier/AnnotatedBeansIntegrationTest.java

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+package com.baeldung.countingbeans.olderspring.qualifier;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = {MyComponent.class, MyConfigurationBean.class})
+public class AnnotatedBeansIntegrationTest {
+
+    @Autowired
+    @MyCustomAnnotation
+    private List<Object> annotatedBeans;
+
+    @Test
+    void whenAutowiring_ThenShouldDetectAllAnnotatedBeans() {
+        assertEquals(2, annotatedBeans.size());
+        List<String> classNames = annotatedBeans.stream()
+            .map(Object::getClass)
+            .map(Class::getName)
+            .map(s -> s.substring(s.lastIndexOf(".") + 1))
+            .collect(Collectors.toList());
+        assertTrue(classNames.containsAll(Arrays.asList("MyComponent", "MyService")));
+    }
+
+}