diff --git a/src/main/java/com/example/demo/DemoApplication.java b/src/main/java/com/example/demo/DemoApplication.java
index 2a9bdbe..a8b027b 100644
--- a/src/main/java/com/example/demo/DemoApplication.java
+++ b/src/main/java/com/example/demo/DemoApplication.java
@@ -3,6 +3,13 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
+/*
+ *An informative annotation type used to indicate that an interface type
+ *declaration is intended to be a functional interface as defined by the
+ *Java Language Specification. Conceptually, a functional interface has exactly
+ *one abstract method. Since default methods have an implementation,
+ *they are not abstract.
+ */
 @SpringBootApplication
 public class DemoApplication {
 
diff --git a/src/main/java/com/example/demo/controller/CourseController.java b/src/main/java/com/example/demo/controller/CourseController.java
index 39ad1d8..7ccad5c 100644
--- a/src/main/java/com/example/demo/controller/CourseController.java
+++ b/src/main/java/com/example/demo/controller/CourseController.java
@@ -1,22 +1,48 @@
 package com.example.demo.controller;
 
+import com.example.demo.modal.Course;
+import com.example.demo.modal.dto.CourseDto;
+import com.example.demo.service.CourseService;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
 
+// single function interface
 @RestController
 @RequestMapping
 public class CourseController {
 
-    @GetMapping(path = "/", produces = "application/json")
+    @Autowired // IOC 控制反转
+    CourseService courseService; // Singleton
+    //依赖注入 Dependency Injection
+
+    @GetMapping(path = "/", produces = "application/json") //如果你用get方法 call我这个地址
     public HttpEntity findAllCourses(){
-       // List<CourseDto> allCourses = courseService.findAllCourses();
+        List<Course> allCourses = courseService.findAllCourses(); //我就帮你用这个方法来处理这个请求
+
+        return new ResponseEntity<>(allCourses,HttpStatus.OK); // 我返回结果给你
+    }
+
+//    @GetMapping(path = "/api/course/findAllCourses", produces = "application/json")
+//    public HttpEntity<List<CourseDto>> findAllCourses(){
+//        List<CourseDto> allCourses = courseService.findAllCourses();
+//
+//        return new ResponseEntity<>(allCourses, HttpStatus.OK);
+//    }
+
+    @GetMapping(path = "/look-up/{inputString}", produces = "application/json")
+    public HttpEntity<Course> searchCourse(@PathVariable("inputString") String inputString) {
+
+        List<Course> findedCourse = courseService.searchByCourseName(inputString);
 
-        return new ResponseEntity<>("OK",HttpStatus.OK);
+        return new ResponseEntity(findedCourse, HttpStatus.OK);
     }
 }
diff --git a/src/main/java/com/example/demo/modal/Course.java b/src/main/java/com/example/demo/modal/Course.java
new file mode 100644
index 0000000..8917157
--- /dev/null
+++ b/src/main/java/com/example/demo/modal/Course.java
@@ -0,0 +1,20 @@
+package com.example.demo.modal;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.Date;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class Course {
+    private String className;
+    private Instructor instructor;
+    private Date startDate;
+    private Date endDate;
+    private String timeFrame;
+}
diff --git a/src/main/java/com/example/demo/modal/Instructor.java b/src/main/java/com/example/demo/modal/Instructor.java
new file mode 100644
index 0000000..95880a3
--- /dev/null
+++ b/src/main/java/com/example/demo/modal/Instructor.java
@@ -0,0 +1,17 @@
+package com.example.demo.modal;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class Instructor {
+    private String firstName;
+    private String lastName;
+    private String title;
+    private String office;
+}
diff --git a/src/main/java/com/example/demo/modal/dto/CourseDto.java b/src/main/java/com/example/demo/modal/dto/CourseDto.java
new file mode 100644
index 0000000..2185c13
--- /dev/null
+++ b/src/main/java/com/example/demo/modal/dto/CourseDto.java
@@ -0,0 +1,16 @@
+package com.example.demo.modal.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class CourseDto {
+
+    private String courseName;
+
+}
diff --git a/src/main/java/com/example/demo/repository/CourseRepository.java b/src/main/java/com/example/demo/repository/CourseRepository.java
new file mode 100644
index 0000000..92e1f9e
--- /dev/null
+++ b/src/main/java/com/example/demo/repository/CourseRepository.java
@@ -0,0 +1,55 @@
+package com.example.demo.repository;
+
+import com.example.demo.modal.Course;
+import com.example.demo.modal.Instructor;
+import org.springframework.stereotype.Repository;
+
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+
+@Repository
+public class CourseRepository {
+    List<Course> courses = new ArrayList<>();
+
+    // constructor
+    public CourseRepository() {
+        Course javaOne = Course.builder()
+                .className("Java_I")
+                .instructor(new Instructor("Steve", "Jobs", "Phd", "TownHall201"))
+                .startDate(new Date("8/1/2018"))
+                .endDate(new Date("12/24/2018"))
+                .timeFrame("8am-10am")
+                .build();
+        Course two= Course.builder()
+                .className("Java_II")
+                .instructor(new Instructor("Steve", "Jobs", "Phd", "TownHall201"))
+                .startDate(new Date("8/1/2018"))
+                .endDate(new Date("12/24/2018"))
+                .timeFrame("8am-10am")
+                .build();
+
+        courses.add(javaOne);
+        courses.add(two);
+    }
+
+
+    public List<Course> findAllClasses(){
+        //链接数据库
+        //返回数据库的信息
+        return  courses;
+    }
+
+    public List<Course> findAllCourse(String searchByCourseName){
+
+        return new ArrayList<Course>();
+    }
+
+    public List<Course> findCourseByName(String courseName) {
+        if(courseName.equals("Java_I")) {
+            return courses;
+        }
+
+        return new ArrayList<Course>();
+    }
+}
diff --git a/src/main/java/com/example/demo/service/CourseService.java b/src/main/java/com/example/demo/service/CourseService.java
new file mode 100644
index 0000000..6b75193
--- /dev/null
+++ b/src/main/java/com/example/demo/service/CourseService.java
@@ -0,0 +1,29 @@
+package com.example.demo.service;
+
+
+import com.example.demo.modal.Course;
+import com.example.demo.repository.CourseRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+@Component
+public class CourseService {
+
+    @Autowired
+    CourseRepository courseRepository;
+
+    public List<Course> findAllCourses(){
+
+        return courseRepository.findAllClasses();
+    }
+
+    public List<Course> searchByCourseName(String input){
+
+        return courseRepository.findCourseByName(input);
+    }
+
+}
diff --git a/src/test/java/com/example/demo/CourseServiceUnitTest.java b/src/test/java/com/example/demo/CourseServiceUnitTest.java
new file mode 100644
index 0000000..ebcca3a
--- /dev/null
+++ b/src/test/java/com/example/demo/CourseServiceUnitTest.java
@@ -0,0 +1,36 @@
+package com.example.demo;
+
+import com.example.demo.modal.Course;
+import com.example.demo.repository.CourseRepository;
+import com.example.demo.service.CourseService;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static junit.framework.TestCase.assertTrue;
+import static org.mockito.BDDMockito.given;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CourseServiceUnitTest {
+    @Mock
+    private CourseService courseService;
+
+    @Mock
+    private CourseRepository courseRepository;
+
+    @Test
+    public void testCourseService(){
+        List<Course> courseList = new ArrayList<>();
+
+        given(courseRepository.findAllClasses()).willReturn(courseList);
+
+        List<Course> result = courseService.findAllCourses();
+
+        assertTrue(result.isEmpty());
+    }
+
+}