BAEL-3290: Basic injection added

spring-di/src/main/java/com/baeldung/dependency/ioc/AppConfig.java

@@ -0,0 +1,23 @@
+package com.baeldung.dependency.ioc;
+
+import org.springframework.context.annotation.Bean;
+
+public class AppConfig {
+
+    @Bean
+    public Item item1() {
+        return new ItemImpl1();
+    }
+ 
+    @Bean
+    public Store storeThroughConstructorInjection() {
+        return new Store(item1());
+    }
+    
+    @Bean
+    public Store storeThroughSetterInjection() {
+        Store store = new Store();
+        store.setItem(item1());
+        return store;
+    }
+}

spring-di/src/main/java/com/baeldung/dependency/ioc/Item.java

@@ -0,0 +1,5 @@
+package com.baeldung.dependency.ioc;
+
+public interface Item {
+
+}

spring-di/src/main/java/com/baeldung/dependency/ioc/ItemImpl1.java

@@ -0,0 +1,5 @@
+package com.baeldung.dependency.ioc;
+
+public class ItemImpl1 implements Item {
+
+}

spring-di/src/main/java/com/baeldung/dependency/ioc/Store.java

@@ -0,0 +1,23 @@
+package com.baeldung.dependency.ioc;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class Store {
+    
+    @Autowired
+    private Item item;
+    
+    public Store() {}
+    
+    public Store(Item item) {
+        this.item = item;
+    }
+
+    public Item getItem() {
+        return item;
+    }
+
+    public void setItem(Item item) {
+        this.item = item;
+    }
+}

spring-di/src/main/resources/ioc-context.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans
+    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+    
+    <!-- Constructor injection -->
+
+	<bean id="item1" class="org.baeldung.store.ItemImpl1" />
+	<bean id="xml-store-by-constructor" class="org.baeldung.store.Store">
+		<constructor-arg type="ItemImpl1" index="0"	name="item" ref="item1" />
+	</bean>
+	
+	<!-- Setter injection -->
+
+	<bean id="xml-store-by-setter" class="org.baeldung.store.Store">
+		<property name="item" ref="item1" />
+	</bean>
+	
+	<!-- Autowired injection -->
+
+	<bean id="item" class="org.baeldung.store.ItemImpl1" />
+	<bean id="xml-store-by-autowire" class="org.baeldung.store.Store" autowire="byName">
+	</bean>
+	
+	<!-- Lazy instantiation -->
+	
+	<bean id="item1-lazy" class="org.baeldung.store.ItemImpl1" lazy-init="true" />
+	<bean id="xml-store-by-setter-lazy" class="org.baeldung.store.Store">
+		<property name="item" ref="item1-lazy" />
+	</bean>
+
+</beans>

spring-di/src/test/java/com/baeldung/dependency/ioc/XmlAppConfigTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.dependency.ioc;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import org.junit.jupiter.api.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("classpath:/ioc-context.xml")
+public class XmlAppConfigTest {
+    
+    @Autowired
+    @Qualifier("xml-store-by-constructor")
+    private Store storeByConstructorInjection;
+
+    @Test
+    public void givenValidXmlConfig_WhenInjectStoreByConstructorInject_ThenBeanIsNotNull() {
+        assertNotNull(storeByConstructorInjection);
+    }
+}