Initial commit

.gitignore

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+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

README.md

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+# SPR-CL-BEANSCOPES
+
+This coding lab covers unit "Spring Core", module "Inversion of Control". 
+
+## Instructions
+- This project contains the definitions for some beans
+- We can use annotations to define the scope of those beans
+- Look out for @TODO statements to identify where annotations need to be added/modified
+
+## Shouldn't Modify (But Look at for Context)
+- Lab.Beans.ScopeBean.java
+- Test files
+
+## Should Modify
+- Lab.Application.java

config.json

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+{
+    "unit-mapping" : ["Spring Core", "Spring Boot Basics"],
+    "required-extensions" : []
+}

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.revature</groupId>
+    <artifactId>springlabs</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>springlabs</name>
+    <description>Demo project for Spring Boot</description>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.7.11</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <properties>
+        <java.version>11</java.version>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
+            <scope>runtime</scope>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <excludes>
+                        <exclude>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                        </exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

src/main/java/Lab/Application.java

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+package Lab;
+
+import Lab.Beans.ScopedBean;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
+
+/**
+ * The @Configuration class is where the beans of your Spring project will be defined.
+ */
+@Configuration
+public class Application {
+    /**
+     * A bean's scope determines how the bean behaves when that bean is requested from the ApplicationContext - Spring
+     * could be instructed to either provide a newly-instantiated object or reuse an existing object. Below are the
+     * Spring bean scopes:
+     *
+     * Singleton - the default scope, any time a specific bean is requested, the existing object is reused
+     * Prototype - any time a bean is requested a new object is instantiated
+     * Request - only used in web applications - a new object is instantiated once per web request
+     * Session - only used in web applications - a new object is instantiated once per web session
+     * Application - only used in web applications - a new object is instantiated once per web servlet
+     * Websocket - only used in web applications - a new object is instantiated once per websocket
+     */
+
+     /**
+     * The @Scope() annotation here is unnecessary as "singleton" is the default, but this example shows how the
+     * scope can be set.
+     */
+    @Bean
+    @Scope("singleton")
+    public ScopedBean sampleBean(){
+        return new ScopedBean();
+    }
+
+    /**
+     * TODO: correct the following code so that a new ScopedBean is instantiated every time the labBean is requested.
+     */
+    @Bean
+    public ScopedBean labBean(){
+        return new ScopedBean();
+    }
+
+    /**
+     * Main method for manual testing of your code
+     */
+    public static void main(String[] args) {
+        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(Application.class);
+        ScopedBean b1 = (ScopedBean) applicationContext.getBean("sampleBean");
+        ScopedBean b2 = (ScopedBean) applicationContext.getBean("sampleBean");
+
+        System.out.println("sampleBean is singleton-scoped, so any sampleBean retrieved from the app context ");
+        System.out.println("should be the same object. Let's test it with ==, are b1 and b2 the same object?");
+        /*
+        remember that == performs a shallow comparison, and can only check if two objects are literally the same
+        object in memory. This came in useful here!
+        */
+        if(b1 == b2){
+            System.out.println("b1 and b2 are the same object.");
+        }else{
+            System.out.println("b1 and b2 are not the same object.");
+        }
+        ScopedBean b3 = (ScopedBean) applicationContext.getBean("labBean");
+        ScopedBean b4 = (ScopedBean) applicationContext.getBean("labBean");
+
+        System.out.println("You'll need to scope labBean such that b3 and b4 are different objects.");
+        System.out.println("Let's test it with ==, are b1 and b2 the same object?");
+        if(b3 == b4){
+            System.out.println("failure: b3 and b4 are the same object.");
+        }else{
+            System.out.println("success: b3 and b4 are not the same object.");
+        }
+    }
+
+}

src/main/java/Lab/Beans/ScopedBean.java

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+package Lab.Beans;
+
+/**
+ * This class will be used in two different Beans, defined in the class marked @Configuration (Application.class).
+ * No need to modify anything in this class.
+ */
+public class ScopedBean {
+
+}

src/test/java/ScopedBeanTest.java

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+import Lab.Application;
+import Lab.Beans.ScopedBean;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+public class ScopedBeanTest {
+    /**
+     * Requesting the "labBean" multiple times should result in multiple instances. This is the expected behavior
+     * of one of the bean scopes. This test will pass when the bean is set to the proper scope.
+     */
+    @Test
+    public void scopedBeanTest(){
+        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(Application.class);
+        ScopedBean b1 = (ScopedBean) applicationContext.getBean("labBean");
+        ScopedBean b2 = (ScopedBean) applicationContext.getBean("labBean");
+        Assertions.assertTrue(b1!=b2);
+    }
+}