BAEL-3286 added component scan filter example (#7786)

* BAEL-3286 added component scan filter example

* BAEL-3286 added component scan filter example

* Fix alingemnt

* Remove unused class

* Corrected formatting

* formatted code

spring-boot-di/pom.xml

@@ -16,6 +16,10 @@
 	</parent>
 
 	<dependencies>
+		<dependency>
+			<groupId>org.aspectj</groupId>
+			<artifactId>aspectjweaver</artifactId>
+		</dependency>
 
 		<dependency>
 			<groupId>org.springframework.boot</groupId>

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/annotation/Animal.java

@@ -0,0 +1,10 @@
+package com.baeldung.componentscan.filter.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface Animal { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/annotation/ComponentScanAnnotationFilterApp.java

@@ -0,0 +1,21 @@
+package com.baeldung.componentscan.filter.annotation;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
+
+import java.util.Arrays;
+
+@Configuration
+@ComponentScan(includeFilters = @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = Animal.class))
+public class ComponentScanAnnotationFilterApp {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = new AnnotationConfigApplicationContext(ComponentScanAnnotationFilterApp.class);
+        Arrays.stream(applicationContext.getBeanDefinitionNames())
+                .forEach(System.out::println);
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/annotation/Elephant.java

@@ -0,0 +1,4 @@
+package com.baeldung.componentscan.filter.annotation;
+
+@Animal
+public class Elephant { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/aspectj/Cat.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.aspectj;
+
+public class Cat { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/aspectj/ComponentScanCustomFilterApp.java

@@ -0,0 +1,24 @@
+package com.baeldung.componentscan.filter.aspectj;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
+
+import java.util.Arrays;
+
+@Configuration
+@ComponentScan(includeFilters = @ComponentScan.Filter(type = FilterType.ASPECTJ,
+        pattern = "com.baeldung.componentscan.filter.aspectj.* "
+                + "&& !(com.baeldung.componentscan.filter.aspectj.L* "
+                + "|| com.baeldung.componentscan.filter.aspectj.E*)"))
+public class ComponentScanCustomFilterApp {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = new AnnotationConfigApplicationContext(ComponentScanCustomFilterApp.class);
+        Arrays.stream(applicationContext.getBeanDefinitionNames())
+                .forEach(System.out::println);
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/aspectj/Elephant.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.aspectj;
+
+public class Elephant { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/aspectj/Loin.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.aspectj;
+
+public class Loin { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/assignable/Animal.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.assignable;
+
+public interface Animal { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/assignable/Cat.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.assignable;
+
+public class Cat implements Animal { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/assignable/ComponentScanAssignableTypeFilterApp.java

@@ -0,0 +1,21 @@
+package com.baeldung.componentscan.filter.assignable;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
+
+import java.util.Arrays;
+
+@Configuration
+@ComponentScan(includeFilters = @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = Animal.class))
+public class ComponentScanAssignableTypeFilterApp {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = new AnnotationConfigApplicationContext(ComponentScanAssignableTypeFilterApp.class);
+        Arrays.stream(applicationContext.getBeanDefinitionNames())
+                .forEach(System.out::println);
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/assignable/Elephant.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.assignable;
+
+public class Elephant implements Animal { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/custom/Cat.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.custom;
+
+public class Cat extends Pet { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/custom/ComponentScanCustomFilter.java

@@ -0,0 +1,22 @@
+package com.baeldung.componentscan.filter.custom;
+
+import org.springframework.core.type.ClassMetadata;
+import org.springframework.core.type.classreading.MetadataReader;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.core.type.filter.TypeFilter;
+
+import java.io.IOException;
+
+public class ComponentScanCustomFilter implements TypeFilter {
+
+    @Override
+    public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
+            throws IOException {
+        ClassMetadata classMetadata = metadataReader.getClassMetadata();
+        String superClass = classMetadata.getSuperClassName();
+        if (Pet.class.getName().equalsIgnoreCase(superClass)) {
+            return true;
+        }
+        return false;
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/custom/ComponentScanCustomFilterApp.java

@@ -0,0 +1,21 @@
+package com.baeldung.componentscan.filter.custom;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
+
+import java.util.Arrays;
+
+@Configuration
+@ComponentScan(includeFilters = @ComponentScan.Filter(type = FilterType.CUSTOM, classes = ComponentScanCustomFilter.class))
+public class ComponentScanCustomFilterApp {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = new AnnotationConfigApplicationContext(ComponentScanCustomFilterApp.class);
+        Arrays.stream(applicationContext.getBeanDefinitionNames())
+                .forEach(System.out::println);
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/custom/Loin.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.custom;
+
+public class Loin { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/custom/Pet.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.custom;
+
+public class Pet { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/regex/Cat.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.regex;
+
+public class Cat { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/regex/ComponentScanRegexFilterApp.java

@@ -0,0 +1,20 @@
+package com.baeldung.componentscan.filter.regex;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
+
+import java.util.Arrays;
+
+@Configuration
+@ComponentScan(includeFilters = @ComponentScan.Filter(type = FilterType.REGEX, pattern = ".*[t]"))
+public class ComponentScanRegexFilterApp {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = new AnnotationConfigApplicationContext(ComponentScanRegexFilterApp.class);
+        Arrays.stream(applicationContext.getBeanDefinitionNames()).forEach(System.out::println);
+    }
+}

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/regex/Elephant.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.regex;
+
+public class Elephant { }

spring-boot-di/src/main/java/com/baeldung/componentscan/filter/regex/Loin.java

@@ -0,0 +1,3 @@
+package com.baeldung.componentscan.filter.regex;
+
+public class Loin { }