list, set injection

spring-core/src/main/java/com/baeldung/collection/CollectionConfig.java

@@ -4,6 +4,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
 import java.util.Arrays;
+import java.util.HashSet;
 import java.util.List;
 
 @Configuration
@@ -11,11 +12,11 @@ public class CollectionConfig {
 
     @Bean
     public CollectionsBean getCollectionsBean() {
-        return new CollectionsBean();
+        return new CollectionsBean(new HashSet<>(Arrays.asList("John", "Adam", "Harry")));
     }
 
     @Bean
     public List<String> nameList(){
-        return Arrays.asList("John", "Adam", "Harry");
+        return Arrays.asList("John", "Adam", "Harry", null);
     }
 }

spring-core/src/main/java/com/baeldung/collection/CollectionInjectionDemo.java

@@ -9,8 +9,10 @@ import org.springframework.context.annotation.AnnotationConfigApplicationContext
 public class CollectionInjectionDemo {
 
     public static void main(String[] args) {
+
         ApplicationContext context = new AnnotationConfigApplicationContext(CollectionConfig.class);
-        CollectionsBean collectionsBean = (CollectionsBean)context.getBean(CollectionsBean.class);
+        CollectionsBean collectionsBean = context.getBean(CollectionsBean.class);
         collectionsBean.printNameList();
+        collectionsBean.printNameSet();
     }
 }

spring-core/src/main/java/com/baeldung/collection/CollectionsBean.java

@@ -3,6 +3,7 @@ package com.baeldung.collection;
 import org.springframework.beans.factory.annotation.Autowired;
 
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by Gebruiker on 5/18/2018.
@@ -12,7 +13,20 @@ public class CollectionsBean {
     @Autowired
     private List<String> nameList;
 
+    private Set<String> nameSet;
+
+    public CollectionsBean() {
+    }
+
+    public CollectionsBean(Set<String> strings) {
+        this.nameSet = strings;
+    }
+
     public void printNameList() {
         System.out.println(nameList);
     }
+
+    public void printNameSet() {
+        System.out.println(nameSet);
+    }
 }