add Completable future

student-service/student-service/.idea/workspace.xml

@@ -5,25 +5,8 @@
   </component>
   <component name="ChangeListManager">
     <list default="true" id="bd185af2-024c-4245-af2c-5893b8b011d9" name="Changes" comment="">
-      <change afterPath="$PROJECT_DIR$/src/main/java/com/example/student/mapper/StudentMapper.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/dto/ErrorDto.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/dto/TeacherDto.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/mapper/TeacherMapper.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pom.xml" beforeDir="false" afterPath="$PROJECT_DIR$/pom.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/controller/StudentController.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/controller/StudentController.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/dto/StudentDto.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/dto/StudentDto.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/dto/TeacherDto.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/dto/TeacherDto.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/feign/FeignFallBack.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/feign/FeignFallBack.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/responseobject/StudentTeacherResponseVO.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/responseobject/StudentTeacherResponseVO.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/example/student/service/StudentService.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/example/student/service/StudentService.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/controller/StudentController.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/controller/StudentController.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/dto/StudentDto.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/dto/StudentDto.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/dto/TeacherDto.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/dto/TeacherDto.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/feign/FeignFallBack.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/feign/FeignFallBack.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/responseobject/StudentTeacherResponseVO.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/responseobject/StudentTeacherResponseVO.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/target/classes/com/example/student/service/StudentService.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/example/student/service/StudentService.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/../../teacher-service/teacher-service/pom.xml" beforeDir="false" afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/pom.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/TeacherServiceApplication.java" beforeDir="false" afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/TeacherServiceApplication.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/controller/TeacherController.java" beforeDir="false" afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/controller/TeacherController.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/service/TeacherService.java" beforeDir="false" afterPath="$PROJECT_DIR$/../../teacher-service/teacher-service/src/main/java/com/example/teacher/service/TeacherService.java" afterDir="false" />
     </list>

teacher-service/teacher-service/src/main/java/com/example/teacher/TeacherServiceApplication.java

@@ -2,8 +2,10 @@ package com.example.teacher;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableAsync;
 
 @SpringBootApplication
+@EnableAsync
 public class TeacherServiceApplication {
 
 	public static void main(String[] args) {

teacher-service/teacher-service/src/main/java/com/example/teacher/controller/TeacherController.java

@@ -9,8 +9,12 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
 
 @RestController
 @RequestMapping("/teachers")
@@ -27,11 +31,57 @@ public class TeacherController {
     }
 
     // GET methods
-    @GetMapping("/{id}")
-    public ResponseEntity<Optional<Teacher>> findStudentById(@PathVariable int id) {
-        Optional<Teacher> myStudent = teacherService.findTeacherById(id);
-        if (myStudent.isPresent()) {
-            return new ResponseEntity<Optional<Teacher>>(myStudent, HttpStatus.FOUND);
+    @GetMapping("/id-array")
+    public ResponseEntity<List<Teacher>> findTeacherById(@RequestParam int[] id) throws InterruptedException {
+        List<Teacher> teacherList = new ArrayList<>();
+        for (int x: id) {
+            Optional<Teacher> myTeacher = teacherService.findTeacherById(x);
+            myTeacher.ifPresent(teacherList::add);
+        }
+        if (teacherList.size() > 0) {
+            return new ResponseEntity<List<Teacher>>(teacherList, HttpStatus.FOUND);
+        }
+        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+    }
+
+
+//    // Test 1
+//    @GetMapping("/id-array-async")
+//    public ResponseEntity<List<Teacher>> findTeacherByIdAsync(@RequestParam int[] id) throws ExecutionException, InterruptedException {
+//        List<Teacher> teacherList = new ArrayList<>();
+//        List<CompletableFuture<Optional<Teacher>>> completableFutureList = new ArrayList<>();
+//        for (int x: id) {
+//            CompletableFuture<Optional<Teacher>> myCompletableTeacher = teacherService.findTeacherByIdAsync(x);
+//            completableFutureList.add(myCompletableTeacher);
+//        }
+////        completableFutureList.forEach(CompletableFuture::join);
+//        for (CompletableFuture<Optional<Teacher>> x: completableFutureList
+//             ) {
+//            Optional<Teacher> myOptionalTeacher = x.get();
+//            myOptionalTeacher.ifPresent(teacherList::add);
+//        }
+//        if (teacherList.size() > 0) {
+//            return new ResponseEntity<List<Teacher>>(teacherList, HttpStatus.FOUND);
+//        }
+//        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+//    }
+
+    // Test 2
+    @GetMapping("/id-array-async")
+    public ResponseEntity<List<Teacher>> findTeacherByIdAsync(@RequestParam int[] id) throws ExecutionException, InterruptedException {
+        List<Teacher> teacherList = new ArrayList<>();
+        List<CompletableFuture<Optional<Teacher>>> completableFutureList = new ArrayList<>();
+        for (int x: id) {
+            CompletableFuture<Optional<Teacher>> myCompletableTeacher = teacherService.findTeacherByIdAsync(x);
+            completableFutureList.add(myCompletableTeacher);
+        }
+        for (CompletableFuture<Optional<Teacher>> x: completableFutureList
+             ) {
+            Optional<Teacher> teacherOptional = x.join();
+            teacherOptional.ifPresent(teacherList::add);
+        }
+        if (teacherList.size() > 0) {
+            return new ResponseEntity<List<Teacher>>(teacherList, HttpStatus.FOUND);
         }
         return new ResponseEntity<>(HttpStatus.NOT_FOUND);
     }

teacher-service/teacher-service/src/main/java/com/example/teacher/service/TeacherService.java

@@ -5,14 +5,18 @@ import com.example.teacher.dto.TeacherDto;
 import com.example.teacher.mapper.TeacherMapper;
 import com.example.teacher.model.Teacher;
 import com.example.teacher.repository.TeacherRepository;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.*;
 import java.util.stream.Collectors;
 
+@Slf4j
 @Service
 public class TeacherService {
 
@@ -22,6 +26,8 @@ public class TeacherService {
     @Autowired
     private TeacherMapper mapper;
 
+    // Create A ThreadPool
+    ExecutorService service = Executors.newFixedThreadPool(10);
     public Teacher createAndUpdateTeacher(Teacher teacher) {
         teacher.setActive(true);
         return teacherRepository.save(teacher);
@@ -35,13 +41,29 @@ public class TeacherService {
                 .collect(Collectors.toList());
     }
 
-    public Optional<Teacher> findTeacherById(int id) {
-        if (teacherRepository.findTeacherById(id).isActive()){
-            return teacherRepository.findById(id);
+    // GET Teacher By ID Synchronously
+    public Optional<Teacher> findTeacherById(int id) throws InterruptedException {
+        Thread.sleep(500);
+        log.info("GET Teacher of id " + id + " by Thread " + Thread.currentThread().getName());
+        Optional<Teacher> myTeacher = teacherRepository.findById(id);
+        if (myTeacher.isPresent() && myTeacher.get().isActive()){
+            return myTeacher;
         }
         return Optional.empty();
     }
 
+    // GET Teacher By ID Asynchronously
+    @Async
+    public CompletableFuture<Optional<Teacher>> findTeacherByIdAsync(int id) throws InterruptedException {
+        Thread.sleep(500);
+        log.info("GET Teacher of id " + id + " by Thread " + Thread.currentThread().getName());
+        Optional<Teacher> myTeacher = teacherRepository.findById(id);
+        if (myTeacher.isPresent() && myTeacher.get().isActive()){
+            return CompletableFuture.completedFuture(myTeacher);
+        }
+        return CompletableFuture.completedFuture(Optional.empty());
+    }
+
     public TeacherDto findTeacherByName(String name) {
         Teacher teacher =  teacherRepository.findTeacherByName(name);
         if (teacher == null) {