Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

spring-di/src/main/java/com/baeldung/circulardependency/CircularDependencyA.java

@@ -0,0 +1,29 @@
+package com.baeldung.circulardependency;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CircularDependencyA implements ApplicationContextAware, InitializingBean {
+
+	private CircularDependencyB circB;
+
+	private ApplicationContext context;
+
+	public CircularDependencyB getCircB() {
+		return circB;
+	}
+
+	@Override
+	public void afterPropertiesSet() throws Exception {
+		circB = context.getBean(CircularDependencyB.class);
+	}
+
+	@Override
+	public void setApplicationContext(final ApplicationContext ctx) throws BeansException {
+		context = ctx;
+	}
+}

spring-di/src/main/java/com/baeldung/circulardependency/CircularDependencyB.java

@@ -0,0 +1,22 @@
+package com.baeldung.circulardependency;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CircularDependencyB {
+
+	private CircularDependencyA circA;
+
+	private String message = "Hi!";
+
+	@Autowired
+	public void setCircA(final CircularDependencyA circA) {
+		this.circA = circA;
+	}
+
+	public String getMessage() {
+		return message;
+	}
+
+}

spring-di/src/main/java/com/baeldung/constructordi/Config.java

@@ -0,0 +1,23 @@
+package com.baeldung.constructordi;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+import com.baeldung.constructordi.domain.Engine;
+import com.baeldung.constructordi.domain.Transmission;
+
+@Configuration
+@ComponentScan("com.baeldung.constructordi")
+public class Config {
+
+    @Bean
+    public Engine engine() {
+        return new Engine("v8", 5);
+    }
+
+    @Bean
+    public Transmission transmission() {
+        return new Transmission("sliding");
+    }
+}

spring-di/src/main/java/com/baeldung/constructordi/SpringRunner.java

@@ -0,0 +1,31 @@
+package com.baeldung.constructordi;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import com.baeldung.constructordi.domain.Car;
+
+public class SpringRunner {
+    public static void main(String[] args) {
+        Car toyota = getCarFromXml();
+
+        System.out.println(toyota);
+
+        toyota = getCarFromJavaConfig();
+
+        System.out.println(toyota);
+    }
+
+    private static Car getCarFromJavaConfig() {
+        ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);
+
+        return context.getBean(Car.class);
+    }
+
+    private static Car getCarFromXml() {
+        ApplicationContext context = new ClassPathXmlApplicationContext("constructordi.xml");
+
+        return context.getBean(Car.class);
+    }
+}

spring-di/src/main/java/com/baeldung/constructordi/domain/Car.java

@@ -0,0 +1,21 @@
+package com.baeldung.constructordi.domain;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class Car {
+    private Engine engine;
+    private Transmission transmission;
+
+    @Autowired
+    public Car(Engine engine, Transmission transmission) {
+        this.engine = engine;
+        this.transmission = transmission;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Engine: %s Transmission: %s", engine, transmission);
+    }
+}

spring-di/src/main/java/com/baeldung/constructordi/domain/Engine.java

@@ -0,0 +1,16 @@
+package com.baeldung.constructordi.domain;
+
+public class Engine {
+    private String type;
+    private int volume;
+
+    public Engine(String type, int volume) {
+        this.type = type;
+        this.volume = volume;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s %d", type, volume);
+    }
+}

spring-di/src/main/java/com/baeldung/constructordi/domain/Transmission.java

@@ -0,0 +1,14 @@
+package com.baeldung.constructordi.domain;
+
+public class Transmission {
+	private String type;
+
+	public Transmission(String type) {
+		this.type = type;
+	}
+
+	@Override
+	public String toString() {
+		return String.format("%s", type);
+	}
+}

spring-di/src/main/java/com/baeldung/dependency/AnotherArbitraryDependency.java

@@ -0,0 +1,13 @@
+package com.baeldung.dependency;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class AnotherArbitraryDependency extends ArbitraryDependency {
+
+    private final String label = "Another Arbitrary Dependency";
+
+    public String toString() {
+        return label;
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/ArbitraryDependency.java

@@ -0,0 +1,13 @@
+package com.baeldung.dependency;
+
+import org.springframework.stereotype.Component;
+
+@Component(value = "autowiredFieldDependency")
+public class ArbitraryDependency {
+
+    private final String label = "Arbitrary Dependency";
+
+    public String toString() {
+        return label;
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/YetAnotherArbitraryDependency.java

@@ -0,0 +1,13 @@
+package com.baeldung.dependency;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class YetAnotherArbitraryDependency extends ArbitraryDependency {
+
+    private final String label = "Yet Another Arbitrary Dependency";
+
+    public String toString() {
+        return label;
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/exception/app/PurchaseDeptService.java

@@ -0,0 +1,14 @@
+package com.baeldung.dependency.exception.app;
+
+import com.baeldung.dependency.exception.repository.InventoryRepository;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Service;
+
+@Service
+public class PurchaseDeptService {
+    private InventoryRepository repository;
+
+    public PurchaseDeptService(@Qualifier("dresses") InventoryRepository repository) {
+        this.repository = repository;
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/exception/app/SpringDependenciesExampleApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.dependency.exception.app;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.dependency.exception")
+public class SpringDependenciesExampleApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringDependenciesExampleApplication.class, args);
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/exception/repository/DressRepository.java

@@ -0,0 +1,10 @@
+package com.baeldung.dependency.exception.repository;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Primary;
+import org.springframework.stereotype.Repository;
+
+@Qualifier("dresses")
+@Repository
+public class DressRepository implements InventoryRepository {
+}

spring-di/src/main/java/com/baeldung/dependency/exception/repository/InventoryRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.dependency.exception.repository;
+
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface InventoryRepository {
+}

spring-di/src/main/java/com/baeldung/dependency/exception/repository/ShoeRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.dependency.exception.repository;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Repository;
+
+@Qualifier("shoes")
+@Repository
+public class ShoeRepository implements InventoryRepository {
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/ArticleFormatter.java

@@ -0,0 +1,16 @@
+package com.baeldung.dependencyinjectiontypes;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+public class ArticleFormatter {
+
+    @SuppressWarnings("resource")
+    public static void main(String[] args) {    	
+        ApplicationContext context = new ClassPathXmlApplicationContext("dependencyinjectiontypes-context.xml");
+        ArticleWithSetterInjection article = (ArticleWithSetterInjection) context.getBean("articleWithSetterInjectionBean");
+        String formattedArticle = article.format("This is a text !");
+        
+        System.out.print(formattedArticle);
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/ArticleWithConstructorInjection.java

@@ -0,0 +1,17 @@
+package com.baeldung.dependencyinjectiontypes;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class ArticleWithConstructorInjection {
+
+	private TextFormatter formatter;
+
+	@Autowired
+    public ArticleWithConstructorInjection(TextFormatter formatter) {
+        this.formatter = formatter;
+    }
+
+    public String format(String text) {
+        return formatter.format(text);
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/ArticleWithSetterInjection.java

@@ -0,0 +1,21 @@
+package com.baeldung.dependencyinjectiontypes;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class ArticleWithSetterInjection {
+
+    private TextFormatter formatter;
+
+    public ArticleWithSetterInjection(TextFormatter formatter) {
+        this.formatter = formatter;
+    }
+
+    @Autowired
+    public void setTextFormatter(TextFormatter formatter) {
+        this.formatter = formatter;
+    }
+    
+    public String format(String text) {
+        return formatter.format(text);
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/TextFormatter.java

@@ -0,0 +1,8 @@
+package com.baeldung.dependencyinjectiontypes;
+
+public class TextFormatter {
+
+    public String format(String text) {
+        return text.toUpperCase();
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/annotation/CarQualifier.java

@@ -0,0 +1,15 @@
+package com.baeldung.dependencyinjectiontypes.annotation;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.FIELD, ElementType.METHOD,
+        ElementType.TYPE, ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+@Qualifier
+public @interface CarQualifier {
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/app/CustomConfiguration.java

@@ -0,0 +1,39 @@
+package com.baeldung.dependencyinjectiontypes.app;
+
+import com.baeldung.dependencyinjectiontypes.annotation.CarQualifier;
+import com.baeldung.dependencyinjectiontypes.model.Car;
+import com.baeldung.dependencyinjectiontypes.model.CarHandler;
+import com.baeldung.dependencyinjectiontypes.model.Motorcycle;
+import com.baeldung.dependencyinjectiontypes.model.Vehicle;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan("com.baeldung.dependencyinjectiontypes.model")
+public class CustomConfiguration {
+	@Bean
+	@CarQualifier
+	public Car getMercedes() {
+		return new Car("E280", "Mercedes", "Diesel");
+	}
+
+	public static void main(String[] args) throws NoSuchFieldException {
+		ConfigurableApplicationContext context = SpringApplication.run(CustomConfiguration.class, args);
+		CarHandler carHandler = context.getBean(CarHandler.class);
+		carHandler.getVehicles().forEach(System.out::println);
+	}
+
+	@Bean
+	@CarQualifier
+	public Car getBmw() {
+		return new Car("M5", "BMW", "Petrol");
+	}
+
+	@Bean
+	public Motorcycle getSuzuki() {
+		return new Motorcycle("Yamaguchi", "Suzuki", true);
+	}
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/model/Car.java

@@ -0,0 +1,25 @@
+package com.baeldung.dependencyinjectiontypes.model;
+
+public class Car extends Vehicle {
+    private String engineType;
+
+    public Car(String name, String manufacturer, String engineType) {
+        super(name, manufacturer);
+        this.engineType = engineType;
+    }
+
+    public String getEngineType() {
+        return engineType;
+    }
+
+    public void setEngineType(String engineType) {
+        this.engineType = engineType;
+    }
+
+    @Override
+    public String toString() {
+        return "Car{" +
+                "engineType='" + engineType + '\'' +
+                '}';
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/model/CarHandler.java

@@ -0,0 +1,26 @@
+package com.baeldung.dependencyinjectiontypes.model;
+
+import com.baeldung.dependencyinjectiontypes.annotation.CarQualifier;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.ResolvableType;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+
+@Component
+public class CarHandler {
+
+    @Autowired
+    @CarQualifier
+    private List<Vehicle> vehicles;
+
+    public List<Vehicle> getVehicles() throws NoSuchFieldException {
+        ResolvableType vehiclesType = ResolvableType.forField(getClass().getDeclaredField("vehicles"));
+        System.out.println(vehiclesType);
+        ResolvableType type = vehiclesType.getGeneric();
+        System.out.println(type);
+        Class<?> aClass = type.resolve();
+        System.out.println(aClass);
+        return this.vehicles;
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/model/Motorcycle.java

@@ -0,0 +1,25 @@
+package com.baeldung.dependencyinjectiontypes.model;
+
+public class Motorcycle extends Vehicle {
+    private boolean twoWheeler;
+
+    public Motorcycle(String name, String manufacturer, boolean twoWheeler) {
+        super(name, manufacturer);
+        this.twoWheeler = true;
+    }
+
+    public boolean isTwoWheeler() {
+        return twoWheeler;
+    }
+
+    public void setTwoWheeler(boolean twoWheeler) {
+        this.twoWheeler = twoWheeler;
+    }
+
+    @Override
+    public String toString() {
+        return "Motorcycle{" +
+                "twoWheeler=" + twoWheeler +
+                '}';
+    }
+}

spring-di/src/main/java/com/baeldung/dependencyinjectiontypes/model/Vehicle.java

@@ -0,0 +1,28 @@
+package com.baeldung.dependencyinjectiontypes.model;
+
+public abstract class Vehicle {
+    private String name;
+    private String manufacturer;
+
+
+    public Vehicle(String name, String manufacturer) {
+        this.name = name;
+        this.manufacturer = manufacturer;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getManufacturer() {
+        return manufacturer;
+    }
+
+    public void setManufacturer(String manufacturer) {
+        this.manufacturer = manufacturer;
+    }
+}

spring-di/src/main/java/com/baeldung/dependson/DriverApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.dependson;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+import com.baeldung.dependson.config.Config;
+import com.baeldung.dependson.file.processor.FileProcessor;
+
+public class DriverApplication {
+    public static void main(String[] args) {
+        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
+        ctx.getBean(FileProcessor.class);
+        ctx.close();
+    }
+}

spring-di/src/main/java/com/baeldung/dependson/config/Config.java

@@ -0,0 +1,38 @@
+package com.baeldung.dependson.config;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.DependsOn;
+import org.springframework.context.annotation.Lazy;
+
+import com.baeldung.dependson.file.processor.FileProcessor;
+import com.baeldung.dependson.file.reader.FileReader;
+import com.baeldung.dependson.file.writer.FileWriter;
+import com.baeldung.dependson.shared.File;
+
+@Configuration
+@ComponentScan("com.baeldung.dependson")
+public class Config {
+    
+    @Autowired
+    File file;
+    
+    @Bean("fileProcessor")
+    @DependsOn({"fileReader","fileWriter"})
+    @Lazy
+    public FileProcessor fileProcessor(){
+        return new FileProcessor(file);
+    }
+    
+    @Bean("fileReader")
+    public FileReader fileReader(){
+        return new FileReader(file);
+    }
+    
+    @Bean("fileWriter")
+    public FileWriter fileWriter(){
+        return new FileWriter(file);
+    }
+}

spring-di/src/main/java/com/baeldung/dependson/file/processor/FileProcessor.java

@@ -0,0 +1,19 @@
+package com.baeldung.dependson.file.processor;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+import com.baeldung.dependson.file.reader.FileReader;
+import com.baeldung.dependson.file.writer.FileWriter;
+import com.baeldung.dependson.shared.File;
+
+public class FileProcessor {
+
+    File file;
+      
+    public FileProcessor(File file){
+        this.file = file;
+        if(file.getText().contains("write") && file.getText().contains("read")){
+            file.setText("processed");
+        }
+    }  
+}

spring-di/src/main/java/com/baeldung/dependson/file/reader/FileReader.java

@@ -0,0 +1,12 @@
+package com.baeldung.dependson.file.reader;
+
+import com.baeldung.dependson.shared.File;
+
+public class FileReader {
+
+    public FileReader(File file) {
+        file.setText("read");
+    }
+    
+    public void readFile() {}
+}

spring-di/src/main/java/com/baeldung/dependson/file/writer/FileWriter.java

@@ -0,0 +1,13 @@
+package com.baeldung.dependson.file.writer;
+
+import com.baeldung.dependson.shared.File;
+
+
+public class FileWriter {
+    
+    public FileWriter(File file){
+        file.setText("write");
+    }
+    
+    public void writeFile(){}
+}

spring-di/src/main/java/com/baeldung/dependson/shared/File.java

@@ -0,0 +1,17 @@
+package com.baeldung.dependson.shared;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class File {
+
+    private String text = "";
+
+    public String getText() {
+        return text;
+    }
+
+    public void setText(String text) {
+        this.text = this.text+text;
+    }
+}

spring-di/src/main/java/com/baeldung/di/spring/Account.java

@@ -0,0 +1,27 @@
+package com.baeldung.di.spring;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class Account {
+
+	private String accountNumber;
+	private String type;
+
+	public String getAccountNumber() {
+		return accountNumber;
+	}
+
+	public void setAccountNumber(String accountNumber) {
+		this.accountNumber = accountNumber;
+	}
+
+	public String getType() {
+		return type;
+	}
+
+	public void setType(String type) {
+		this.type = type;
+	}
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AccountService.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface AccountService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AccountServiceImpl.java

@@ -0,0 +1,8 @@
+package com.baeldung.di.spring;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class AccountServiceImpl implements AccountService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AudioBookService.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface AudioBookService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AudioBookServiceImpl.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public class AudioBookServiceImpl implements AudioBookService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AuthorService.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface AuthorService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/AuthorServiceImpl.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public class AuthorServiceImpl implements AuthorService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/BookService.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface BookService {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/BookServiceImpl.java

@@ -0,0 +1,10 @@
+package com.baeldung.di.spring;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class BookServiceImpl implements BookService {
+
+	@Autowired(required = false)
+	private AuthorService authorService;
+
+}

spring-di/src/main/java/com/baeldung/di/spring/Foo.java

@@ -0,0 +1,4 @@
+package com.baeldung.di.spring;
+
+public class Foo {
+}

spring-di/src/main/java/com/baeldung/di/spring/FooProcessor.java

@@ -0,0 +1,6 @@
+package com.baeldung.di.spring;
+
+public class FooProcessor {
+
+	private Foo foo;
+}

spring-di/src/main/java/com/baeldung/di/spring/IService.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface IService {
+    public String serve();
+}

spring-di/src/main/java/com/baeldung/di/spring/IndexApp.java

@@ -0,0 +1,19 @@
+package com.baeldung.di.spring;
+
+public class IndexApp {
+
+    private IService service;
+
+    public String getServiceValue() {
+        return service.serve();
+    }
+
+    public IService getService() {
+        return service;
+    }
+
+    public void setService(IService service) {
+        this.service = service;
+    }
+
+}

spring-di/src/main/java/com/baeldung/di/spring/IndexService.java

@@ -0,0 +1,10 @@
+package com.baeldung.di.spring;
+
+public class IndexService implements IService {
+
+    @Override
+    public String serve() {
+        return "Hello World";
+    }
+
+}

spring-di/src/main/java/com/baeldung/di/spring/InstanceServiceFactory.java

@@ -0,0 +1,14 @@
+package com.baeldung.di.spring;
+
+public class InstanceServiceFactory {
+    public IService getService(int number) {
+        switch (number) {
+        case 1:
+            return new MessageService("Foo");
+        case 0:
+            return new IndexService();
+        default:
+            throw new IllegalArgumentException("Unknown parameter " + number);
+        }
+    }
+}

spring-di/src/main/java/com/baeldung/di/spring/MessageApp.java

@@ -0,0 +1,14 @@
+package com.baeldung.di.spring;
+
+public class MessageApp {
+
+    private IService iService;
+
+    public MessageApp(IService iService) {
+        this.iService = iService;
+    }
+
+    public String getServiceValue() {
+        return iService.serve();
+    }
+}

spring-di/src/main/java/com/baeldung/di/spring/MessageService.java

@@ -0,0 +1,16 @@
+package com.baeldung.di.spring;
+
+public class MessageService implements IService {
+
+    private String message;
+
+    public MessageService(String message) {
+        this.message = message;
+    }
+
+    @Override
+    public String serve() {
+        return message;
+    }
+
+}

spring-di/src/main/java/com/baeldung/di/spring/PersonDao.java

@@ -0,0 +1,5 @@
+package com.baeldung.di.spring;
+
+public interface PersonDao {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/PersonDaoImpl.java

@@ -0,0 +1,8 @@
+package com.baeldung.di.spring;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class PersonDaoImpl implements PersonDao {
+
+}

spring-di/src/main/java/com/baeldung/di/spring/SpringBeansConfig.java

@@ -0,0 +1,14 @@
+package com.baeldung.di.spring;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class SpringBeansConfig {
+
+	@Bean
+	public AudioBookService audioBookServiceGenerator() {
+		return new AudioBookServiceImpl();
+	}
+
+}

spring-di/src/main/java/com/baeldung/di/spring/SpringMainConfig.java

@@ -0,0 +1,18 @@
+package com.baeldung.di.spring;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+@Configuration
+@Import({ SpringBeansConfig.class })
+@ComponentScan("com.baeldung.di.spring")
+public class SpringMainConfig {
+
+	@Bean
+	public BookService bookServiceGenerator() {
+		return new BookServiceImpl();
+	}
+
+}

spring-di/src/main/java/com/baeldung/di/spring/SpringPersonService.java

@@ -0,0 +1,20 @@
+package com.baeldung.di.spring;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class SpringPersonService {
+
+    @Autowired
+    private PersonDao personDao;
+
+    public PersonDao getPersonDao() {
+        return personDao;
+    }
+
+    public void setPersonDao(PersonDao personDao) {
+        this.personDao = personDao;
+    }
+
+}

spring-di/src/main/java/com/baeldung/di/spring/StaticServiceFactory.java

@@ -0,0 +1,14 @@
+package com.baeldung.di.spring;
+
+public class StaticServiceFactory {
+    public static IService getService(int number) {
+        switch (number) {
+        case 1:
+            return new MessageService("Foo");
+        case 0:
+            return new IndexService();
+        default:
+            throw new IllegalArgumentException("Unknown parameter " + number);
+        }
+    }
+}

spring-di/src/main/java/com/baeldung/di/spring/UserService.java

@@ -0,0 +1,20 @@
+package com.baeldung.di.spring;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class UserService {
+
+	@Autowired
+	private AccountService accountService;
+
+	public AccountService getAccountService() {
+		return accountService;
+	}
+
+	public void setAccountService(AccountService accountService) {
+		this.accountService = accountService;
+	}
+
+}

spring-di/src/main/java/com/baeldung/methodinjections/AppConfig.java

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

spring-di/src/main/java/com/baeldung/methodinjections/Grader.java

@@ -0,0 +1,19 @@
+package com.baeldung.methodinjections;
+
+import java.util.Collection;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class Grader {
+
+    public String grade(Collection<Integer> marks) {
+
+        boolean result = marks.stream()
+            .anyMatch(mark -> mark < 45);
+        if (result) {
+            return "FAIL";
+        }
+        return "PASS";
+    }
+}

spring-di/src/main/java/com/baeldung/methodinjections/SchoolNotification.java

@@ -0,0 +1,45 @@
+package com.baeldung.methodinjections;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Component;
+
+@Component("schoolNotification")
+@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
+public class SchoolNotification {
+    @Autowired
+    Grader grader;
+
+    private String name;
+    private Collection<Integer> marks;
+
+    public SchoolNotification(String name) {
+        this.name = name;
+        this.marks = new ArrayList<Integer>();
+    }
+
+    public String addMark(Integer mark) {
+        this.marks.add(mark);
+        return this.grader.grade(this.marks);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Collection<Integer> getMarks() {
+        return marks;
+    }
+
+    public void setMarks(Collection<Integer> marks) {
+        this.marks = marks;
+    }
+}

spring-di/src/main/java/com/baeldung/methodinjections/Student.java

@@ -0,0 +1,27 @@
+package com.baeldung.methodinjections;
+
+import org.springframework.beans.factory.annotation.Lookup;
+import org.springframework.stereotype.Component;
+
+@Component("studentBean")
+public class Student {
+
+    private String id;
+
+    /**
+     * Injects a prototype bean SchoolNotification into Singleton student
+     */
+    @Lookup
+    public SchoolNotification getNotification(String name) {
+        // spring overrides and returns a SchoolNotification instance
+        return null;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+}

spring-di/src/main/java/com/baeldung/methodinjections/StudentServices.java

@@ -0,0 +1,21 @@
+package com.baeldung.methodinjections;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Lookup;
+import org.springframework.stereotype.Component;
+
+@Component("studentService")
+public abstract class StudentServices {
+
+    private Map<String, SchoolNotification> notes = new HashMap<>();
+
+    @Lookup
+    protected abstract SchoolNotification getNotification(String name);
+
+    public String appendMark(String name, Integer mark) {
+        SchoolNotification notification = notes.computeIfAbsent(name, exists -> getNotification(name));
+        return notification.addMark(mark);
+    }
+}

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

@@ -0,0 +1,11 @@
+package com.baeldung.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/src/main/java/com/baeldung/sample/AppConfig.java

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

spring-di/src/main/java/com/baeldung/sample/Bar.java

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

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

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

spring-di/src/main/java/com/baeldung/sample/Foo.java

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

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

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

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

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

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

@@ -0,0 +1,17 @@
+package com.baeldung.sample;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class FooService {
+
+    @Autowired
+    @FormatterType("Foo")
+    private Formatter formatter;
+
+    public String doStuff() {
+        return formatter.format();
+    }
+
+}

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

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

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

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