From faa095541e892742208610bd849d8f3063638b68 Mon Sep 17 00:00:00 2001
From: Khoteeswarun Gangadharan  NCS <gangadharan.k@ncs.com.sg>
Date: Wed, 24 Jan 2018 14:59:01 +0800
Subject: [PATCH 1/2] Spring Dependency Injection Types

---
 .../AboutuspageService.java                   | 11 +++++++
 .../dependencyinjections/HomepageService.java | 11 +++++++
 .../dependencyinjections/Website.java         | 18 +++++++++++
 ...WebsiteControllerConstructorInjection.java | 27 +++++++++++++++++
 .../WebsiteControllerSetterInjection.java     | 30 +++++++++++++++++++
 .../dependencyinjections-context.xml          | 25 ++++++++++++++++
 6 files changed, 122 insertions(+)
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/HomepageService.java
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
 create mode 100644 spring-core/src/main/resources/dependencyinjections-context.xml

diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
new file mode 100644
index 000000000000..f8ceb9e14fc1
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
@@ -0,0 +1,11 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class AboutuspageService {
+
+    public String getContents() {
+        return "Aboutus page contents";
+    }
+}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/HomepageService.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/HomepageService.java
new file mode 100644
index 000000000000..d1a54b837623
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/HomepageService.java
@@ -0,0 +1,11 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class HomepageService {
+
+    public String getContents() {
+        return "Home page contents";
+    }
+}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
new file mode 100644
index 000000000000..9a627a04d91d
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
@@ -0,0 +1,18 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+public class Website {
+
+    @SuppressWarnings("resource")
+    public static void main(String[] args) {
+        ApplicationContext context = new ClassPathXmlApplicationContext("dependencyinjections-context.xml");
+
+        WebsiteControllerConstructorInjection controller = (WebsiteControllerConstructorInjection) context.getBean("websiteControllerConstructorInjection");
+        System.out.println("The contents of the Website are : " + controller.getContentsViaConstructorInjection());
+
+        WebsiteControllerSetterInjection controllerwithSetterInjection = (WebsiteControllerSetterInjection) context.getBean("websiteControllerSetterInjection");
+        System.out.println("The contents of the Website are : " + controllerwithSetterInjection.getContentsViaSetterInjection());
+    }
+}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
new file mode 100644
index 000000000000..93de5dc6e56e
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
@@ -0,0 +1,27 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class WebsiteControllerConstructorInjection {
+
+    private HomepageService homeService;
+
+    private AboutuspageService aboutusService;
+
+    @Autowired
+    public WebsiteControllerConstructorInjection(HomepageService homeService, AboutuspageService aboutusService) {
+        this.homeService = homeService;
+        this.aboutusService = aboutusService;
+    }
+
+    public String getContentsViaConstructorInjection() {
+        StringBuffer websiteContents = new StringBuffer();
+        websiteContents.append(homeService.getContents());
+        websiteContents.append(" and ");
+        websiteContents.append(aboutusService.getContents());
+        return websiteContents.toString();
+    }
+
+}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
new file mode 100644
index 000000000000..3f2f356145d6
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
@@ -0,0 +1,30 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class WebsiteControllerSetterInjection {
+
+    private HomepageService homeService;
+
+    private AboutuspageService aboutusService;
+
+    @Autowired
+    public void setHomepageService(HomepageService homeService) {
+        this.homeService = homeService;
+    }
+
+    @Autowired
+    public void setAboutuspageService(AboutuspageService aboutusService) {
+        this.aboutusService = aboutusService;
+    }
+
+    public String getContentsViaSetterInjection() {
+        StringBuffer websiteContents = new StringBuffer();
+        websiteContents.append(homeService.getContents());
+        websiteContents.append(" and ");
+        websiteContents.append(aboutusService.getContents());
+        return websiteContents.toString();
+    }
+}
diff --git a/spring-core/src/main/resources/dependencyinjections-context.xml b/spring-core/src/main/resources/dependencyinjections-context.xml
new file mode 100644
index 000000000000..2cc984265465
--- /dev/null
+++ b/spring-core/src/main/resources/dependencyinjections-context.xml
@@ -0,0 +1,25 @@
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
+	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
+	xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
+	xmlns:task="http://www.springframework.org/schema/task" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd">
+   
+   <context:annotation-config/>	
+	
+	<bean id="homeService" class="com.baeldung.dependencyinjections.HomepageService">
+	</bean>
+	
+	<bean id="aboutusService" class="com.baeldung.dependencyinjections.AboutuspageService">
+	</bean>
+	
+	<bean id="websiteControllerConstructorInjection"
+		class="com.baeldung.dependencyinjections.WebsiteControllerConstructorInjection">
+		<constructor-arg ref="homeService" />
+		<constructor-arg ref="aboutusService" />
+	</bean>	
+	
+	<bean id="websiteControllerSetterInjection"
+		class="com.baeldung.dependencyinjections.WebsiteControllerSetterInjection">		
+	</bean>		
+	
+</beans>
\ No newline at end of file

From 1c53d9e0a508e1ef53a2eb0bb0968bdacc3f9e75 Mon Sep 17 00:00:00 2001
From: Khoteeswarun Gangadharan  NCS <gangadharan.k@ncs.com.sg>
Date: Thu, 25 Jan 2018 11:56:51 +0800
Subject: [PATCH 2/2] Spring Dependency Injection Types - Updated

---
 .../AboutuspageService.java                   | 11 -----
 .../dependencyinjections/AppConfig.java       | 23 +++++++++++
 .../dependencyinjections/Website.java         | 11 ++---
 ...WebsiteControllerConstructorInjection.java | 11 +----
 .../WebsiteControllerSetterInjection.java     | 13 +-----
 .../dependencyinjections-context.xml          |  4 --
 .../dependencyinjections/WebsiteTest.java     | 41 +++++++++++++++++++
 7 files changed, 73 insertions(+), 41 deletions(-)
 delete mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
 create mode 100644 spring-core/src/main/java/com/baeldung/dependencyinjections/AppConfig.java
 create mode 100644 spring-core/src/test/java/com/baeldung/dependencyinjections/WebsiteTest.java

diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
deleted file mode 100644
index f8ceb9e14fc1..000000000000
--- a/spring-core/src/main/java/com/baeldung/dependencyinjections/AboutuspageService.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.baeldung.dependencyinjections;
-
-import org.springframework.stereotype.Service;
-
-@Service
-public class AboutuspageService {
-
-    public String getContents() {
-        return "Aboutus page contents";
-    }
-}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/AppConfig.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/AppConfig.java
new file mode 100644
index 000000000000..54234cb21d68
--- /dev/null
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/AppConfig.java
@@ -0,0 +1,23 @@
+package com.baeldung.dependencyinjections;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class AppConfig {
+
+    @Bean
+    public WebsiteControllerConstructorInjection websiteControllerConstructorInjection() {
+        return new WebsiteControllerConstructorInjection(homepageService());
+    }
+
+    @Bean
+    public HomepageService homepageService() {
+        return new HomepageService();
+    }
+
+    @Bean
+    public WebsiteControllerSetterInjection websiteControllerSetterInjection() {
+        return new WebsiteControllerSetterInjection();
+    }
+}
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
index 9a627a04d91d..bf6eb945fd87 100644
--- a/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/Website.java
@@ -1,18 +1,19 @@
 package com.baeldung.dependencyinjections;
 
 import org.springframework.context.ApplicationContext;
-import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
 public class Website {
 
     @SuppressWarnings("resource")
     public static void main(String[] args) {
-        ApplicationContext context = new ClassPathXmlApplicationContext("dependencyinjections-context.xml");
 
-        WebsiteControllerConstructorInjection controller = (WebsiteControllerConstructorInjection) context.getBean("websiteControllerConstructorInjection");
-        System.out.println("The contents of the Website are : " + controller.getContentsViaConstructorInjection());
+        ApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
+
+        WebsiteControllerConstructorInjection controller = context.getBean(WebsiteControllerConstructorInjection.class);
+        System.out.println("The contents of the Website includes : " + controller.getContentsViaConstructorInjection());
 
         WebsiteControllerSetterInjection controllerwithSetterInjection = (WebsiteControllerSetterInjection) context.getBean("websiteControllerSetterInjection");
-        System.out.println("The contents of the Website are : " + controllerwithSetterInjection.getContentsViaSetterInjection());
+        System.out.println("The contents of the Website includes : " + controllerwithSetterInjection.getContentsViaSetterInjection());
     }
 }
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
index 93de5dc6e56e..1bfeccb151f3 100644
--- a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerConstructorInjection.java
@@ -8,20 +8,13 @@ public class WebsiteControllerConstructorInjection {
 
     private HomepageService homeService;
 
-    private AboutuspageService aboutusService;
-
     @Autowired
-    public WebsiteControllerConstructorInjection(HomepageService homeService, AboutuspageService aboutusService) {
+    public WebsiteControllerConstructorInjection(HomepageService homeService) {
         this.homeService = homeService;
-        this.aboutusService = aboutusService;
     }
 
     public String getContentsViaConstructorInjection() {
-        StringBuffer websiteContents = new StringBuffer();
-        websiteContents.append(homeService.getContents());
-        websiteContents.append(" and ");
-        websiteContents.append(aboutusService.getContents());
-        return websiteContents.toString();
+        return homeService.getContents();
     }
 
 }
diff --git a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
index 3f2f356145d6..ac4e93f0cdac 100644
--- a/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
+++ b/spring-core/src/main/java/com/baeldung/dependencyinjections/WebsiteControllerSetterInjection.java
@@ -8,23 +8,12 @@ public class WebsiteControllerSetterInjection {
 
     private HomepageService homeService;
 
-    private AboutuspageService aboutusService;
-
     @Autowired
     public void setHomepageService(HomepageService homeService) {
         this.homeService = homeService;
     }
 
-    @Autowired
-    public void setAboutuspageService(AboutuspageService aboutusService) {
-        this.aboutusService = aboutusService;
-    }
-
     public String getContentsViaSetterInjection() {
-        StringBuffer websiteContents = new StringBuffer();
-        websiteContents.append(homeService.getContents());
-        websiteContents.append(" and ");
-        websiteContents.append(aboutusService.getContents());
-        return websiteContents.toString();
+        return homeService.getContents();
     }
 }
diff --git a/spring-core/src/main/resources/dependencyinjections-context.xml b/spring-core/src/main/resources/dependencyinjections-context.xml
index 2cc984265465..972bf92f439e 100644
--- a/spring-core/src/main/resources/dependencyinjections-context.xml
+++ b/spring-core/src/main/resources/dependencyinjections-context.xml
@@ -9,13 +9,9 @@
 	<bean id="homeService" class="com.baeldung.dependencyinjections.HomepageService">
 	</bean>
 	
-	<bean id="aboutusService" class="com.baeldung.dependencyinjections.AboutuspageService">
-	</bean>
-	
 	<bean id="websiteControllerConstructorInjection"
 		class="com.baeldung.dependencyinjections.WebsiteControllerConstructorInjection">
 		<constructor-arg ref="homeService" />
-		<constructor-arg ref="aboutusService" />
 	</bean>	
 	
 	<bean id="websiteControllerSetterInjection"
diff --git a/spring-core/src/test/java/com/baeldung/dependencyinjections/WebsiteTest.java b/spring-core/src/test/java/com/baeldung/dependencyinjections/WebsiteTest.java
new file mode 100644
index 000000000000..d87c6a1d5e95
--- /dev/null
+++ b/spring-core/src/test/java/com/baeldung/dependencyinjections/WebsiteTest.java
@@ -0,0 +1,41 @@
+package com.baeldung.dependencyinjections;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+public class WebsiteTest {
+
+    ApplicationContext annotationContext = new AnnotationConfigApplicationContext(AppConfig.class);
+    ApplicationContext xmlContext = new ClassPathXmlApplicationContext("dependencyinjections-context.xml");
+
+    public static final String EXPECTED_STRING = "Home page contents";
+
+    @Test
+    public void testAnnotationConfigConstructorBasedDI() {
+        WebsiteControllerConstructorInjection controller = annotationContext.getBean(WebsiteControllerConstructorInjection.class);
+        assertEquals(EXPECTED_STRING, controller.getContentsViaConstructorInjection());
+    }
+
+    @Test
+    public void testXMLConfigConstructorBasedDI() {
+        WebsiteControllerConstructorInjection controller = xmlContext.getBean(WebsiteControllerConstructorInjection.class);
+        assertEquals(EXPECTED_STRING, controller.getContentsViaConstructorInjection());
+    }
+
+    @Test
+    public void testAnnotationConfigSetterBasedDI() {
+        WebsiteControllerSetterInjection controllerwithSetterInjection = (WebsiteControllerSetterInjection) annotationContext.getBean("websiteControllerSetterInjection");
+        assertEquals(EXPECTED_STRING, controllerwithSetterInjection.getContentsViaSetterInjection());
+    }
+
+    @Test
+    public void testXMLConfigSetterBasedDI() {
+        WebsiteControllerSetterInjection controllerwithSetterInjection = (WebsiteControllerSetterInjection) xmlContext.getBean("websiteControllerSetterInjection");
+        assertEquals(EXPECTED_STRING, controllerwithSetterInjection.getContentsViaSetterInjection());
+    }
+
+}