진하늘 과제1

hn/build.gradle

@@ -24,6 +24,11 @@ dependencies {
     developmentOnly 'org.springframework.boot:spring-boot-devtools'
     annotationProcessor 'org.projectlombok:lombok'
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
+
+    implementation platform("org.springframework.cloud:spring-cloud-dependencies:2021.0.5")
+    implementation 'org.springframework.cloud:spring-cloud-starter-openfeign'
+
+    implementation 'org.apache.commons:commons-math3:3.6.1'
 }
 
 tasks.named('test') {

hn/src/main/java/com/example/hn/HnApplication.java

@@ -2,8 +2,10 @@
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.openfeign.EnableFeignClients;
 
 @SpringBootApplication
+@EnableFeignClients
 public class HnApplication {
 
     public static void main(String[] args) {

hn/src/main/java/com/example/hn/homework1/api/YkApi.java

@@ -0,0 +1,13 @@
+package com.example.hn.homework1.api;
+
+import com.example.hn.homework1.response.YkServiceResponse;
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+
+
+@FeignClient(name="homework1-yk", url="http://localhost:8081")
+public interface YkApi {
+    @GetMapping(value="/api/cal/{x}")
+    YkServiceResponse getAnswer(@PathVariable("x")int x);
+}

hn/src/main/java/com/example/hn/homework1/controller/HomeworkController.java

@@ -0,0 +1,22 @@
+package com.example.hn.homework1.controller;
+
+import com.example.hn.homework1.response.ABResponse;
+import com.example.hn.homework1.response.ApiResponse;
+import com.example.hn.homework1.service.HomeworkService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequiredArgsConstructor
+public class HomeworkController {
+
+    private final HomeworkService homeworkService;
+
+    @GetMapping("/hn/homework1")
+    public ApiResponse getAnswer(){
+
+        ABResponse response=homeworkService.getAnswer();
+        return ApiResponse.ok(response);
+    }
+}

hn/src/main/java/com/example/hn/homework1/response/ABResponse.java

@@ -0,0 +1,18 @@
+package com.example.hn.homework1.response;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Setter
+@Getter
+public class ABResponse {
+    private int a;
+    private int b;
+
+    public static ABResponse of(int a, int b) {
+        ABResponse abResponse=new ABResponse();
+        abResponse.setA(a);
+        abResponse.setB(b);
+        return abResponse;
+    }
+}

hn/src/main/java/com/example/hn/homework1/response/ApiResponse.java

@@ -0,0 +1,23 @@
+package com.example.hn.homework1.response;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.ToString;
+
+@Getter
+@AllArgsConstructor
+@ToString
+public class ApiResponse<T> {
+
+    private final String message;
+    private final int code;
+    private final T data;
+
+    public static <T> ApiResponse<T> ok(T data){
+        return new ApiResponse<>(
+                "성공",
+                200,
+                data
+        );
+    }
+}

hn/src/main/java/com/example/hn/homework1/response/YkServiceResponse.java

@@ -0,0 +1,9 @@
+package com.example.hn.homework1.response;
+
+import lombok.*;
+
+@Getter
+@AllArgsConstructor
+public class YkServiceResponse {
+    private int answer;
+}

hn/src/main/java/com/example/hn/homework1/service/HomeworkService.java

@@ -0,0 +1,68 @@
+package com.example.hn.homework1.service;
+
+import com.example.hn.homework1.response.ABResponse;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+import javax.print.attribute.IntegerSyntax;
+import java.util.Arrays;
+import java.util.stream.IntStream;
+
+import org.apache.commons.math3.linear.Array2DRowRealMatrix;
+import org.apache.commons.math3.linear.MatrixUtils;
+import org.apache.commons.math3.linear.RealMatrix;
+import org.apache.commons.math3.linear.SingularMatrixException;
+
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class HomeworkService {
+
+    private final YkService ykService;
+
+    public ABResponse getAnswer() {
+        int x1 = 2;
+        int x2 = 3;
+        int answer1 = ykService.getAnswer(x1);
+        int answer2 = ykService.getAnswer(x2);
+
+        double[][] matrixData = {
+                {x1 * x1, x1},
+                {x2 * x2, x2}
+        };
+        log.debug(printMatrix(matrixData));
+
+        double[] resultData = {answer1, answer2};
+
+
+        RealMatrix matrix = new Array2DRowRealMatrix(matrixData);
+        RealMatrix resultMatrix = new Array2DRowRealMatrix(resultData);
+
+
+        RealMatrix inverseMatrix = MatrixUtils.inverse(matrix);
+        log.debug(printMatrix(inverseMatrix.getData()));
+
+
+        RealMatrix solutionMatrix = inverseMatrix.multiply(resultMatrix);
+
+
+        double[] solution = solutionMatrix.getColumn(0);
+        int a = (int) Math.round(solution[0]);
+        int b = (int) Math.round(solution[1]);
+        log.debug("a:" + a + ", b:" + b);
+
+
+        return ABResponse.of(a, b);
+
+    }
+
+    public String printMatrix(double[][] matrix) {
+        StringBuilder str = new StringBuilder();
+        IntStream.range(0, matrix.length)
+                .forEach(e -> str.append(Arrays.toString(matrix[e]) + "\n"));
+
+        return str.toString();
+    }
+}

hn/src/main/java/com/example/hn/homework1/service/YkService.java

@@ -0,0 +1,20 @@
+package com.example.hn.homework1.service;
+
+import com.example.hn.homework1.api.YkApi;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+@RequiredArgsConstructor
+@Service
+@Slf4j
+public class YkService {
+
+    private final YkApi ykApi;
+
+    public int getAnswer(int x) {
+        int answer=ykApi.getAnswer(x).getAnswer();
+        log.debug("answer="+answer);
+        return answer;
+    }
+}

hn/src/main/resources/application.properties

@@ -1 +1 @@
-
+server.port=8082