진하늘 과제1

hn/build.gradle

@@ -24,6 +24,15 @@ 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'
+
+    testImplementation "org.springframework.cloud:spring-cloud-contract-wiremock:3.1.5"
+    implementation 'com.fasterxml.jackson.core:jackson-databind:2.12.5'
+
 }
 
 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 = "${feign.ykapi-url}", primary = false)
+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 +1,17 @@
+package com.example.hn.homework1.response;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.Setter;
+
+@Setter
+@Getter
+@AllArgsConstructor
+public class ABResponse {
+    private int a;
+    private int b;
+
+    public static ABResponse of(int a, int b) {
+        return new ABResponse(a, b);
+    }
+}

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 +1,12 @@
+package com.example.hn.homework1.response;
+
+import lombok.*;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class YkServiceResponse {
+    private int answer;
+}

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

@@ -0,0 +1,61 @@
+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("입력 행렬:{}", printMatrix(matrixData));
+
+        double[] resultData = {answer1, answer2};
+
+        RealMatrix matrix = new Array2DRowRealMatrix(matrixData);
+        RealMatrix resultMatrix = new Array2DRowRealMatrix(resultData);
+
+        RealMatrix inverseMatrix = MatrixUtils.inverse(matrix);
+        log.debug("역행렬:{}", 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:{}, b:{}", a, b);
+
+        return ABResponse.of(a, b);
+    }
+
+    private 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.yml

@@ -0,0 +1,9 @@
+server:
+  port: 8082
+
+feign:
+  ykapi-url: http://localhost:8081
+
+#logging:
+#  level:
+#    root: debug

hn/src/test/java/com/example/hn/MockYkApi.java

@@ -0,0 +1,26 @@
+package com.example.hn;
+
+import com.github.tomakehurst.wiremock.WireMockServer;
+import com.github.tomakehurst.wiremock.client.WireMock;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.util.ResourceUtils;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class MockYkApi {
+
+    public static void setupGetAnswerResponse(WireMockServer wireMockServer, String url) throws IOException {
+        Path file = ResourceUtils.getFile("classpath:test-response/ykapi-response.json").toPath();
+        wireMockServer.stubFor(WireMock.get(WireMock.urlMatching(url))
+                .willReturn(
+                        WireMock.aResponse()
+                                .withStatus(HttpStatus.OK.value())
+                                .withHeader("Content-Type", MediaType.APPLICATION_JSON_VALUE)
+                                .withBody(Files.readAllBytes(file))
+                )
+        );
+    }
+}

hn/src/test/java/com/example/hn/WireMockConfig.java

@@ -0,0 +1,15 @@
+package com.example.hn;
+
+import com.github.tomakehurst.wiremock.WireMockServer;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+
+@TestConfiguration
+public class WireMockConfig {
+
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    public WireMockServer ykServiceMock() {
+        return new WireMockServer(8081);
+    }
+}

hn/src/test/java/com/example/hn/homework1/api/YkApiTest.java

@@ -0,0 +1,7 @@
+package com.example.hn.homework1.api;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class YkApiTest {
+
+}

hn/src/test/java/com/example/hn/homework1/service/HomeworkServiceTest.java

@@ -0,0 +1,7 @@
+package com.example.hn.homework1.service;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class HomeworkServiceTest {
+
+}