Evaluation Article

spring-core/src/main/java/com/baeldung/spring/di/DepartmentService.java

@@ -0,0 +1,10 @@
+package com.baeldung.spring.di;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class DepartmentService {
+    public String getDepartment() {
+        return "Management";
+    }
+}

spring-core/src/main/java/com/baeldung/spring/di/EmployeeControllerWithConstructorBasedDI.java

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+package com.baeldung.spring.di;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component("employeeControllerWithConstructorBasedDI")
+public class EmployeeControllerWithConstructorBasedDI {
+
+    private DepartmentService departmentService;
+
+    @Autowired
+    public EmployeeControllerWithConstructorBasedDI(DepartmentService departmentService) {
+        this.departmentService = departmentService;
+    }
+
+    public String getEmployeeDetails() {
+        return "Employee: A, Department: " + departmentService.getDepartment();
+    }
+}

spring-core/src/main/java/com/baeldung/spring/di/EmployeeControllerWithSetterBasedDI.java

@@ -0,0 +1,18 @@
+package com.baeldung.spring.di;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component("employeeControllerWithSetterBasedDI")
+public class EmployeeControllerWithSetterBasedDI {
+    private DepartmentService departmentService;
+
+    @Autowired
+    public void setDepartmentService(DepartmentService departmentService) {
+        this.departmentService = departmentService;
+    }
+
+    public String getEmployeeDetails() {
+        return "Employee: A, Department: " + departmentService.getDepartment();
+    }
+}

spring-core/src/main/resources/spring-di.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:context="http://www.springframework.org/schema/context"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
+<context:component-scan base-package="com.baeldung.spring.di"/>
+</beans>

spring-core/src/test/java/com/baeldung/spring/di/DepdencyInjectionUnitTest.java

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+package com.baeldung.spring.di;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+public class DepdencyInjectionUnitTest {
+
+    private ApplicationContext context;
+
+    @Before
+    public  void oneTimeSetup() {
+        context = new ClassPathXmlApplicationContext("spring-di.xml");
+    }
+
+    @Test
+    public void givenConstructorBasedDI_ThenDependencyValid() {
+        EmployeeControllerWithConstructorBasedDI employee = (EmployeeControllerWithConstructorBasedDI) context
+                                                            .getBean("employeeControllerWithConstructorBasedDI");
+        assertEquals("Employee: A, Department: Management", employee.getEmployeeDetails());
+    }
+
+    @Test
+    public void givenSetterBasedDI_ThenDependencyValid() {
+        EmployeeControllerWithSetterBasedDI employee = (EmployeeControllerWithSetterBasedDI) context
+                                                        .getBean("employeeControllerWithSetterBasedDI");
+        assertEquals("Employee: A, Department: Management", employee.getEmployeeDetails());
+    }
+}