BAEL-3829: example of dynamic bean autowiring in Spring

spring-core-4/src/main/java/com/baeldung/dynamic/autowire/BeanFactoryDynamicAutowireService.java

@@ -0,0 +1,22 @@
+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 final BeanFactory beanFactory;
+
+    @Autowired
+    public BeanFactoryDynamicAutowireService(BeanFactory beanFactory) {
+        this.beanFactory = beanFactory;
+    }
+
+    public boolean isServerActive(String countryCode, int serverId) {
+        RegionService service = beanFactory.getBean(countryCode, RegionService.class);
+
+        return service.isServerActive(serverId);
+    }
+
+}

spring-core-4/src/main/java/com/baeldung/dynamic/autowire/DynamicAutowireConfig.java

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+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-core-4/src/main/java/com/baeldung/dynamic/autowire/InterfaceDynamicAutowireService.java

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+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 InterfaceDynamicAutowireService {
+    private final Map<String, RegionService> servicesByCountryCode;
+
+    @Autowired
+    public InterfaceDynamicAutowireService(List<RegionService> regionServices) {
+        servicesByCountryCode = regionServices.stream()
+                .collect(Collectors.toMap(RegionService::getCountryCode, Function.identity()));
+    }
+
+    public boolean isServerActive(String countryCode, int serverId) {
+        RegionService service = servicesByCountryCode.get(countryCode);
+
+        return service.isServerActive(serverId);
+    }
+}

spring-core-4/src/main/java/com/baeldung/dynamic/autowire/RegionService.java

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+package com.baeldung.dynamic.autowire;
+
+public interface RegionService {
+    boolean isServerActive(int serverId);
+
+    String getCountryCode();
+}

spring-core-4/src/main/java/com/baeldung/dynamic/autowire/USARegionService.java

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+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("usa")
+public class USARegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return true;
+    }
+
+    @Override
+    public String getCountryCode() {
+        return "usa";
+    }
+}

spring-core-4/src/main/java/com/baeldung/dynamic/autowire/UkRegionService.java

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+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("uk")
+public class UkRegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return false;
+    }
+
+    @Override
+    public String getCountryCode() {
+        return "uk";
+    }
+}

spring-core-4/src/test/java/com/baeldung/dynamic/autowire/DynamicAutowireIntegrationTest.java

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+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 InterfaceDynamicAutowireService interfaceDynamicAutowireService;
+
+    @Test
+    public void testConstructWorkerByJava() {
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("uk", 101), is(false));
+        assertThat(interfaceDynamicAutowireService.isServerActive("uk", 101), is(false));
+
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("usa", 101), is(true));
+        assertThat(interfaceDynamicAutowireService.isServerActive("usa", 101), is(true));
+    }
+}