JAVA-19545 Move articles from spring-core-2 module to spring-di-3 module (#13708)

* JAVA-19545 Move articles from spring-core-2 module to spring-di-3 module

* JAVA-19545 Move articles from spring-core-4 module to spring-di-3 module

spring-di-3/src/main/java/com/baeldung/autowire/sample/App.java

@@ -0,0 +1,11 @@
+package com.baeldung.autowire.sample;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+public class App {
+    public static void main(String[] args) {
+        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
+        FooService fooService = ctx.getBean(FooService.class);
+        fooService.doStuff();
+    }
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/AppConfig.java

@@ -0,0 +1,10 @@
+package com.baeldung.autowire.sample;
+
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ComponentScan("com.baeldung.autowire.sample")
+public class AppConfig {
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/BarFormatter.java

@@ -0,0 +1,13 @@
+package com.baeldung.autowire.sample;
+
+import org.springframework.stereotype.Component;
+
+@FormatterType("Bar")
+@Component
+public class BarFormatter implements Formatter {
+
+    public String format() {
+        return "bar";
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/FooDAO.java

@@ -0,0 +1,5 @@
+package com.baeldung.autowire.sample;
+
+public class FooDAO {
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/FooFormatter.java

@@ -0,0 +1,13 @@
+package com.baeldung.autowire.sample;
+
+import org.springframework.stereotype.Component;
+
+@FormatterType("Foo")
+@Component
+public class FooFormatter implements Formatter {
+
+    public String format() {
+        return "foo";
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/FooService.java

@@ -0,0 +1,31 @@
+package com.baeldung.autowire.sample;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+/**
+ * This class presents a field, a constructor, and a setter injection type.
+ * Usually, we'd stick with a single approach for a given property. This is just an educational code.
+ */
+@Component
+public class FooService {
+
+    @Autowired
+    @FormatterType("Foo")
+    private Formatter formatter;
+
+    @Autowired
+    public FooService(@FormatterType("Foo") Formatter formatter) {
+        this.formatter = formatter;
+    }
+
+    @Autowired
+    public void setFormatter(@FormatterType("Foo") Formatter formatter) {
+        this.formatter = formatter;
+    }
+
+    public String doStuff() {
+        return formatter.format();
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/Formatter.java

@@ -0,0 +1,7 @@
+package com.baeldung.autowire.sample;
+
+public interface Formatter {
+
+    String format();
+
+}

spring-di-3/src/main/java/com/baeldung/autowire/sample/FormatterType.java

@@ -0,0 +1,17 @@
+package com.baeldung.autowire.sample;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+
+@Qualifier
+@Target({ ElementType.FIELD, ElementType.METHOD, ElementType.TYPE, ElementType.PARAMETER })
+@Retention(RetentionPolicy.RUNTIME)
+public @interface FormatterType {
+
+    String value();
+
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/BeanFactoryDynamicAutowireService.java

@@ -0,0 +1,27 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class BeanFactoryDynamicAutowireService {
+    private static final String SERVICE_NAME_SUFFIX = "regionService";
+    private final BeanFactory beanFactory;
+
+    @Autowired
+    public BeanFactoryDynamicAutowireService(BeanFactory beanFactory) {
+        this.beanFactory = beanFactory;
+    }
+
+    public boolean isServerActive(String isoCountryCode, int serverId) {
+        RegionService service = beanFactory.getBean(getRegionServiceBeanName(isoCountryCode), RegionService.class);
+
+        return service.isServerActive(serverId);
+    }
+
+    private String getRegionServiceBeanName(String isoCountryCode) {
+        return isoCountryCode + SERVICE_NAME_SUFFIX;
+    }
+
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/CustomMapFromListDynamicAutowireService.java

@@ -0,0 +1,26 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@Service
+public class CustomMapFromListDynamicAutowireService {
+    private final Map<String, RegionService> servicesByCountryCode;
+
+    @Autowired
+    public CustomMapFromListDynamicAutowireService(List<RegionService> regionServices) {
+        servicesByCountryCode = regionServices.stream()
+                .collect(Collectors.toMap(RegionService::getISOCountryCode, Function.identity()));
+    }
+
+    public boolean isServerActive(String isoCountryCode, int serverId) {
+        RegionService service = servicesByCountryCode.get(isoCountryCode);
+
+        return service.isServerActive(serverId);
+    }
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/DynamicAutowireConfig.java

@@ -0,0 +1,9 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ComponentScan("com.baeldung.dynamic.autowire")
+public class DynamicAutowireConfig {
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/GBRegionService.java

@@ -0,0 +1,16 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("GBregionService")
+public class GBRegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return false;
+    }
+
+    @Override
+    public String getISOCountryCode() {
+        return "GB";
+    }
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/RegionService.java

@@ -0,0 +1,7 @@
+package com.baeldung.dynamic.autowire;
+
+public interface RegionService {
+    boolean isServerActive(int serverId);
+
+    String getISOCountryCode();
+}

spring-di-3/src/main/java/com/baeldung/dynamic/autowire/USRegionService.java

@@ -0,0 +1,16 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("USregionService")
+public class USRegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return true;
+    }
+
+    @Override
+    public String getISOCountryCode() {
+        return "US";
+    }
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/AnimalConfiguration.java

@@ -0,0 +1,9 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+@Configuration
+@Import({ MammalConfiguration.class, BirdConfig.class })
+class AnimalConfiguration {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/AnimalScanConfiguration.java

@@ -0,0 +1,9 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ComponentScan
+public class AnimalScanConfiguration {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/Bird.java

@@ -0,0 +1,4 @@
+package com.baeldung.importannotation.animal;
+
+class Bird {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/BirdConfig.java

@@ -0,0 +1,13 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+class BirdConfig {
+
+    @Bean
+    Bird bird() {
+        return new Bird();
+    }
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/Bug.java

@@ -0,0 +1,7 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.stereotype.Component;
+
+@Component(value = "bug")
+class Bug {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/BugConfig.java

@@ -0,0 +1,9 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+@Configuration
+@Import(Bug.class)
+class BugConfig {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/Cat.java

@@ -0,0 +1,4 @@
+package com.baeldung.importannotation.animal;
+
+class Cat {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/CatConfig.java

@@ -0,0 +1,13 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+class CatConfig {
+
+    @Bean
+    Cat cat() {
+        return new Cat();
+    }
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/Dog.java

@@ -0,0 +1,4 @@
+package com.baeldung.importannotation.animal;
+
+class Dog {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/DogConfig.java

@@ -0,0 +1,13 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+class DogConfig {
+
+    @Bean
+    Dog dog() {
+        return new Dog();
+    }
+}

spring-di-3/src/main/java/com/baeldung/importannotation/animal/MammalConfiguration.java

@@ -0,0 +1,9 @@
+package com.baeldung.importannotation.animal;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+@Configuration
+@Import({ DogConfig.class, CatConfig.class })
+class MammalConfiguration {
+}

spring-di-3/src/main/java/com/baeldung/importannotation/zoo/ZooApplication.java

@@ -0,0 +1,11 @@
+package com.baeldung.importannotation.zoo;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+import com.baeldung.importannotation.animal.AnimalScanConfiguration;
+
+@Configuration
+@Import(AnimalScanConfiguration.class)
+class ZooApplication {
+}

spring-di-3/src/main/java/com/baeldung/order/Average.java

@@ -0,0 +1,15 @@
+package com.baeldung.order;
+
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+@Component
+@Order(Ordered.LOWEST_PRECEDENCE)
+public class Average implements Rating {
+
+    @Override
+    public int getRating() {
+        return 3;
+    }
+}

spring-di-3/src/main/java/com/baeldung/order/Excellent.java

@@ -0,0 +1,14 @@
+package com.baeldung.order;
+
+import org.springframework.stereotype.Component;
+import org.springframework.core.annotation.Order;
+
+@Component
+@Order(1)
+public class Excellent implements Rating {
+
+    @Override
+    public int getRating() {
+        return 1;
+    }
+}

spring-di-3/src/main/java/com/baeldung/order/Good.java

@@ -0,0 +1,14 @@
+package com.baeldung.order;
+
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+@Component
+@Order(2)
+public class Good implements Rating {
+
+    @Override
+    public int getRating() {
+        return 2;
+    }
+}

spring-di-3/src/main/java/com/baeldung/order/Rating.java

@@ -0,0 +1,6 @@
+package com.baeldung.order;
+
+public interface Rating {
+    
+    int getRating();
+}

spring-di-3/src/test/java/com/baeldung/autowire/sample/FooServiceIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.autowire.sample;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = AppConfig.class, loader = AnnotationConfigContextLoader.class)
+public class FooServiceIntegrationTest {
+
+    @Autowired
+    FooService fooService;
+
+    @Test
+    public void whenFooFormatterType_thenReturnFoo() {
+        Assert.assertEquals("foo", fooService.doStuff());
+    }
+}

spring-di-3/src/test/java/com/baeldung/dynamic/autowire/DynamicAutowireIntegrationTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.dynamic.autowire;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = DynamicAutowireConfig.class)
+public class DynamicAutowireIntegrationTest {
+
+    @Autowired
+    private BeanFactoryDynamicAutowireService beanFactoryDynamicAutowireService;
+
+    @Autowired
+    private CustomMapFromListDynamicAutowireService customMapFromListDynamicAutowireService;
+
+    @Test
+    public void givenDynamicallyAutowiredBean_whenCheckingServerInGB_thenServerIsNotActive() {
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("GB", 101), is(false));
+        assertThat(customMapFromListDynamicAutowireService.isServerActive("GB", 101), is(false));
+    }
+
+    @Test
+    public void givenDynamicallyAutowiredBean_whenCheckingServerInUS_thenServerIsActive() {
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("US", 101), is(true));
+        assertThat(customMapFromListDynamicAutowireService.isServerActive("US", 101), is(true));
+    }
+}

spring-di-3/src/test/java/com/baeldung/importannotation/animal/AnimalConfigUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.importannotation.animal;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = { AnimalConfiguration.class })
+class AnimalConfigUnitTest {
+
+    @Autowired
+    ApplicationContext context;
+
+    @Test
+    void givenImportedBeans_whenGettingEach_shallFindOnlyTheImportedBeans() {
+        assertThatBeanExists("dog", Dog.class);
+        assertThatBeanExists("cat", Cat.class);
+        assertThatBeanExists("bird", Cat.class);
+    }
+
+    private void assertThatBeanExists(String beanName, Class<?> beanClass) {
+        assertTrue(context.containsBean(beanName));
+        assertNotNull(context.getBean(beanClass));
+    }
+}

spring-di-3/src/test/java/com/baeldung/importannotation/animal/BugConfigUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.importannotation.animal;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = BugConfig.class)
+class BugConfigUnitTest {
+
+    @Autowired
+    ApplicationContext context;
+
+    @Test
+    void givenImportInComponent_whenLookForBean_shallFindIt() {
+        assertTrue(context.containsBean("bug"));
+        assertNotNull(context.getBean(Bug.class));
+    }
+}

spring-di-3/src/test/java/com/baeldung/importannotation/animal/ConfigUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.importannotation.animal;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = { BirdConfig.class, CatConfig.class, DogConfig.class })
+class ConfigUnitTest {
+
+    @Autowired
+    ApplicationContext context;
+
+    @Test
+    void givenImportedBeans_whenGettingEach_shallFindIt() {
+        assertThatBeanExists("dog", Dog.class);
+        assertThatBeanExists("cat", Cat.class);
+        assertThatBeanExists("bird", Bird.class);
+    }
+
+    private void assertThatBeanExists(String beanName, Class<?> beanClass) {
+        assertTrue(context.containsBean(beanName));
+        assertNotNull(context.getBean(beanClass));
+    }
+}

spring-di-3/src/test/java/com/baeldung/importannotation/animal/MammalConfigUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.importannotation.animal;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = { MammalConfiguration.class })
+class MammalConfigUnitTest {
+
+    @Autowired
+    ApplicationContext context;
+
+    @Test
+    void givenImportedBeans_whenGettingEach_shallFindOnlyTheImportedBeans() {
+        assertThatBeanExists("dog", Dog.class);
+        assertThatBeanExists("cat", Cat.class);
+
+        assertFalse(context.containsBean("bird"));
+    }
+
+    private void assertThatBeanExists(String beanName, Class<?> beanClass) {
+        assertTrue(context.containsBean(beanName));
+        assertNotNull(context.getBean(beanClass));
+    }
+}

spring-di-3/src/test/java/com/baeldung/importannotation/zoo/ZooApplicationUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.importannotation.zoo;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = ZooApplication.class)
+class ZooApplicationUnitTest {
+
+    @Autowired
+    ApplicationContext context;
+
+    @Test
+    void givenTheScanInTheAnimalPackage_whenGettingAnyAnimal_shallFindItInTheContext() {
+        assertNotNull(context.getBean("dog"));
+        assertNotNull(context.getBean("bird"));
+        assertNotNull(context.getBean("cat"));
+        assertNotNull(context.getBean("bug"));
+    }
+}

spring-di-3/src/test/java/com/baeldung/order/RatingRetrieverUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.order;
+
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+import java.util.List;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(loader = AnnotationConfigContextLoader.class)
+public class RatingRetrieverUnitTest {
+    
+    @Configuration 
+    @ComponentScan(basePackages = {"com.baeldung.order"})
+    static class ContextConfiguration {} 
+    
+    @Autowired
+    private List<Rating> ratings;
+    
+    @Test
+    public void givenOrderOnComponents_whenInjected_thenAutowireByOrderValue() {
+        assertThat(ratings.get(0).getRating(), is(equalTo(1)));
+        assertThat(ratings.get(1).getRating(), is(equalTo(2)));
+        assertThat(ratings.get(2).getRating(), is(equalTo(3)));
+    }
+
+}