Bael 5265: OpenFeign and Spring Exception handler (#12468)

* Implemented cassandra batch query

* Added netty version param

* Reformatted correctly

* Reformatted correctly

* Reformatted correctly

* Formatting fix resolved

* Formatting fix resolved

* Removed unused method

* Refactored method for better readability

* tab spaces corrected

* Added http headers in feign

* Updated code

* Updated code

* Removed unused code

* Removed unused logger code

* Implemented Interceptor and logging related code review

* Added AuthService Code

* Removed toString method

* Removed unnecessary declaration

* Removed new line

* Added feign headers log as well

* Moved to Authorisation package for better naming

* spaces removed

* @Override included

* [Saikat]| Adding the OpenFeign exception default and customizable exception handler and test cases

* [Saikat]| Test name updated

* [Saikat]| Test name updated

* [Saikat]| Removed unused import

* [Saikat]| Refactored code

* [Saikat]| Reformatted the test codes

* [Saikat]| Removed unnecessary code

* [Saikat]| Controller test fixed for data error

* [Saikat]| Code review fixes

* [Saikat]| Code review fixes

* [Saikat]| Removed unnecessary annotation

* [Saikat]| Added extends ResponseEntityExceptionHandler

* [Saikat]| Code review implemented

* [Saikat]| Indentation added

* Removed empty line before method start

Co-authored-by: saikat chakraborty <saikat.chakraborty@tesco.com>

spring-cloud-modules/spring-cloud-openfeign/pom.xml

@@ -61,6 +61,12 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.github.tomakehurst</groupId>
+            <artifactId>wiremock-jre8</artifactId>
+            <version>2.33.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <properties>

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/client/ProductClient.java

@@ -0,0 +1,17 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.client;
+
+import com.baeldung.cloud.openfeign.customizederrorhandling.config.FeignConfig;
+import com.baeldung.cloud.openfeign.defaulterrorhandling.model.Product;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+
+@FeignClient(name = "product-client-2", url = "http://localhost:8081/product/", configuration = FeignConfig.class)
+public interface ProductClient {
+
+    @RequestMapping(value = "{id}", method = RequestMethod.GET)
+    Product getProduct(@PathVariable(value = "id") String id);
+
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/config/CustomErrorDecoder.java

@@ -0,0 +1,24 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.config;
+
+import com.baeldung.cloud.openfeign.exception.BadRequestException;
+import com.baeldung.cloud.openfeign.customizederrorhandling.exception.ProductNotFoundException;
+import com.baeldung.cloud.openfeign.customizederrorhandling.exception.ProductServiceNotAvailableException;
+import feign.Response;
+import feign.codec.ErrorDecoder;
+
+public class CustomErrorDecoder implements ErrorDecoder {
+
+    @Override
+    public Exception decode(String methodKey, Response response) {
+        switch (response.status()){
+            case 400:
+                return new BadRequestException();
+            case 404:
+                return new ProductNotFoundException("Product not found");
+            case 503:
+                return new ProductServiceNotAvailableException("Product Api is unavailable");
+            default:
+                return new Exception("Exception while getting product details");
+        }
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/config/FeignConfig.java

@@ -0,0 +1,18 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.config;
+
+import feign.Logger;
+import feign.codec.ErrorDecoder;
+import org.springframework.context.annotation.Bean;
+
+public class FeignConfig {
+
+    @Bean
+    Logger.Level feignLoggerLevel() {
+        return Logger.Level.FULL;
+    }
+
+    @Bean
+    ErrorDecoder errorDecoder() {
+        return new CustomErrorDecoder();
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/controller/ProductController.java

@@ -0,0 +1,27 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.controller;
+
+import com.baeldung.cloud.openfeign.customizederrorhandling.client.ProductClient;
+
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.model.Product;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+
+
+@RestController("product_controller2")
+@RequestMapping(value = "myapp2")
+public class ProductController {
+
+    private final ProductClient productClient;
+
+    @Autowired
+    public ProductController(ProductClient productClient) {
+        this.productClient = productClient;
+    }
+
+    @GetMapping("/product/{id}")
+    public Product getProduct(@PathVariable String id) {
+        return productClient.getProduct(id);
+    }
+
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/exception/ErrorResponse.java

@@ -0,0 +1,54 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.exception;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.springframework.http.HttpStatus;
+
+import java.util.Date;
+
+public class ErrorResponse {
+
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
+    private Date timestamp;
+
+    @JsonProperty(value = "code")
+    private int code;
+
+    @JsonProperty(value = "status")
+    private String status;
+    @JsonProperty(value = "message")
+    private String message;
+    @JsonProperty(value = "details")
+    private String details;
+
+    public ErrorResponse() {
+    }
+
+    public ErrorResponse(HttpStatus httpStatus, String message, String details) {
+        timestamp = new Date();
+        this.code = httpStatus.value();
+        this.status = httpStatus.name();
+        this.message = message;
+        this.details = details;
+    }
+
+    public Date getTimestamp() {
+        return timestamp;
+    }
+
+    public int getCode() {
+        return code;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public String getDetails() {
+        return details;
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/exception/ProductExceptionHandler.java

@@ -0,0 +1,40 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.exception;
+
+import com.baeldung.cloud.openfeign.exception.BadRequestException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+@RestControllerAdvice
+public class ProductExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler({ProductServiceNotAvailableException.class})
+    public ResponseEntity<ErrorResponse> handleProductServiceNotAvailableException(ProductServiceNotAvailableException exception, WebRequest request) {
+        return new ResponseEntity<>(new ErrorResponse(
+          HttpStatus.INTERNAL_SERVER_ERROR,
+          exception.getMessage(),
+          request.getDescription(false)),
+          HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+
+    @ExceptionHandler({ProductNotFoundException.class})
+    public ResponseEntity<ErrorResponse> handleProductNotFoundException(ProductNotFoundException exception, WebRequest request) {
+        return new ResponseEntity<>(new ErrorResponse(
+          HttpStatus.NOT_FOUND,
+          exception.getMessage(),
+          request.getDescription(false)),
+          HttpStatus.NOT_FOUND);
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ErrorResponse> handleGenericException(Exception exception, WebRequest request) {
+        return new ResponseEntity<>(new ErrorResponse(
+          HttpStatus.INTERNAL_SERVER_ERROR,
+          exception.getMessage(),
+          request.getDescription(false)),
+          HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/exception/ProductNotFoundException.java

@@ -0,0 +1,8 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.exception;
+
+public class ProductNotFoundException extends RuntimeException {
+
+    public ProductNotFoundException(String message) {
+        super(message);
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/customizederrorhandling/exception/ProductServiceNotAvailableException.java

@@ -0,0 +1,8 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.exception;
+
+public class ProductServiceNotAvailableException extends RuntimeException {
+
+    public ProductServiceNotAvailableException(String message) {
+        super(message);
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/defaulterrorhandling/client/ProductClient.java

@@ -0,0 +1,17 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.client;
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.config.FeignConfig;
+import com.baeldung.cloud.openfeign.defaulterrorhandling.model.Product;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+
+@FeignClient(name = "product-client", url = "http://localhost:8081/product/", configuration = FeignConfig.class)
+public interface ProductClient {
+
+    @RequestMapping(value = "{id}", method = RequestMethod.GET)
+    Product getProduct(@PathVariable(value = "id") String id);
+
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/defaulterrorhandling/config/FeignConfig.java

@@ -0,0 +1,12 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.config;
+
+import feign.Logger;
+import org.springframework.context.annotation.Bean;
+
+public class FeignConfig {
+
+    @Bean
+    Logger.Level feignLoggerLevel() {
+        return Logger.Level.FULL;
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/defaulterrorhandling/controller/ProductController.java

@@ -0,0 +1,24 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.controller;
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.client.ProductClient;
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.model.Product;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+
+@RestController("product_controller1")
+@RequestMapping(value ="myapp1")
+public class ProductController {
+
+    private final ProductClient productClient;
+
+    @Autowired
+    public ProductController(ProductClient productClient) {
+        this.productClient = productClient;
+    }
+
+    @GetMapping("/product/{id}")
+    public Product getProduct(@PathVariable String id) {
+        return productClient.getProduct(id);
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/main/java/com/baeldung/cloud/openfeign/defaulterrorhandling/model/Product.java

@@ -0,0 +1,24 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.model;
+
+public class Product {
+
+    private String id;
+
+    private String productName;
+
+    private double price;
+
+
+    public String getId() {
+        return id;
+    }
+
+    public String getProductName() {
+        return productName;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+}

spring-cloud-modules/spring-cloud-openfeign/src/test/java/com/baeldung/cloud/openfeign/customizederrorhandling/client/ProductClientUnitTest.java

@@ -0,0 +1,57 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.client;
+
+import com.baeldung.cloud.openfeign.customizederrorhandling.exception.ProductNotFoundException;
+import com.baeldung.cloud.openfeign.customizederrorhandling.exception.ProductServiceNotAvailableException;
+import com.github.tomakehurst.wiremock.WireMockServer;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static org.junit.Assert.assertThrows;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class ProductClientUnitTest {
+
+    @Autowired
+    private ProductClient productClient;
+
+    private WireMockServer wireMockServer;
+
+    @Before
+    public void startWireMockServer() {
+        wireMockServer = new WireMockServer(8081);
+        configureFor("localhost", 8081);
+        wireMockServer.start();
+    }
+
+    @After
+    public void stopWireMockServer() {
+        wireMockServer.stop();
+    }
+
+    @Test
+    public void givenProductApiIsNotAvailable_whenGetProductCalled_thenThrowProductServiceNotAvailableException() {
+        String productId = "test";
+
+        stubFor(get(urlEqualTo("/product/" + productId))
+                .willReturn(aResponse().withStatus(503)));
+
+        assertThrows(ProductServiceNotAvailableException.class, () -> productClient.getProduct(productId));
+    }
+
+    @Test
+    public void givenProductNotFound_whenGetProductCalled_thenThrowBadRequestException() {
+        String productId = "test";
+
+        stubFor(get(urlEqualTo("/product/" + productId))
+                .willReturn(aResponse().withStatus(404)));
+
+        assertThrows(ProductNotFoundException.class, () -> productClient.getProduct(productId));
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/test/java/com/baeldung/cloud/openfeign/customizederrorhandling/controller/ProductControllerUnitTest.java

@@ -0,0 +1,98 @@
+package com.baeldung.cloud.openfeign.customizederrorhandling.controller;
+
+import com.baeldung.cloud.openfeign.customizederrorhandling.client.ProductClient;
+import com.baeldung.cloud.openfeign.customizederrorhandling.exception.ErrorResponse;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.github.tomakehurst.wiremock.WireMockServer;
+import com.github.tomakehurst.wiremock.client.WireMock;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.cloud.openfeign.FeignAutoConfiguration;
+import org.springframework.http.HttpStatus;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static org.junit.Assert.assertEquals;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+
+@RunWith(SpringRunner.class)
+@WebMvcTest(ProductController.class)
+@ImportAutoConfiguration({FeignAutoConfiguration.class})
+public class ProductControllerUnitTest {
+
+    @Autowired
+    private ProductClient productClient;
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    private WireMockServer wireMockServer;
+
+    @Before
+    public void startWireMockServer() {
+        wireMockServer = new WireMockServer(8081);
+        configureFor("localhost", 8081);
+        wireMockServer.start();
+    }
+
+    @After
+    public void stopWireMockServer() {
+        wireMockServer.stop();
+    }
+
+    @Test
+    public void givenProductApiIsNotAvailable_whenGetProductCalled_ThenReturnInternalServerError() throws Exception {
+        String productId = "test";
+
+        stubFor(WireMock.get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse()
+            .withStatus(HttpStatus.SERVICE_UNAVAILABLE.value())));
+
+        ErrorResponse expectedError = new ErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR,
+          "Product Api is unavailable","uri=/myapp2/product/" + productId);
+
+        MvcResult result = mockMvc.perform(get("/myapp2/product/" + productId))
+            .andExpect(status().isInternalServerError()).andReturn();
+
+        ErrorResponse errorResponse = objectMapper.readValue(result.getResponse().getContentAsString(), ErrorResponse.class);
+
+        assertEquals(expectedError.getCode(), errorResponse.getCode());
+        assertEquals(expectedError.getMessage(), errorResponse.getMessage());
+        assertEquals(expectedError.getStatus(), errorResponse.getStatus());
+        assertEquals(expectedError.getDetails(), errorResponse.getDetails());
+    }
+
+    @Test
+    public void givenProductIsNotFound_whenGetProductCalled_ThenReturnInternalServerError() throws Exception {
+        String productId = "test";
+
+        stubFor(WireMock.get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse()
+            .withStatus(HttpStatus.NOT_FOUND.value())));
+
+        ErrorResponse expectedError = new ErrorResponse(HttpStatus.NOT_FOUND,
+          "Product not found","uri=/myapp2/product/" + productId);
+
+        MvcResult result = mockMvc.perform(get("/myapp2/product/" + productId))
+            .andExpect(status().isNotFound()).andReturn();
+
+        ErrorResponse errorResponse = objectMapper.readValue(result.getResponse().getContentAsString(), ErrorResponse.class);
+
+        assertEquals(expectedError.getCode(), errorResponse.getCode());
+        assertEquals(expectedError.getMessage(), errorResponse.getMessage());
+        assertEquals(expectedError.getStatus(), errorResponse.getStatus());
+        assertEquals(expectedError.getDetails(), errorResponse.getDetails());
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/test/java/com/baeldung/cloud/openfeign/defaulterrorhandling/client/ProductClientUnitTest.java

@@ -0,0 +1,84 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.client;
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.model.Product;
+import com.github.tomakehurst.wiremock.WireMockServer;
+import feign.FeignException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.HttpStatus;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class ProductClientUnitTest {
+
+    @Autowired
+    private ProductClient productClient;
+
+    private WireMockServer wireMockServer;
+
+    @Before
+    public void startWireMockServer() {
+        wireMockServer = new WireMockServer(8081);
+        configureFor("localhost", 8081);
+        wireMockServer.start();
+    }
+
+    @After
+    public void stopWireMockServer() {
+        wireMockServer.stop();
+    }
+
+    @Test
+    public void givenProductIsAvailable_whenGetProductCalled_thenReturnMatchingProduct() {
+        String productId = "test";
+
+        String productResponse = "{ " +
+                "    \"id\":\"test\",\n" +
+                "    \"productName\":\"Watermelon\",\n" +
+                "    \"price\":12\n" +
+                "}";
+
+        stubFor(get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse()
+            .withStatus(HttpStatus.OK.value())
+            .withHeader("Content-Type", "application/json")
+            .withBody(productResponse)));
+
+        Product product = productClient.getProduct(productId);
+
+        assertEquals(productId, product.getId());
+        assertEquals("Watermelon", product.getProductName());
+        assertEquals(12.00d, product.getPrice(), 0.00d);
+    }
+
+    @Test
+    public void givenProductApiIsNotAvailable_whenGetProductCalled_thenThrowFeignException() {
+        String productId = "test";
+
+        stubFor(get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse()
+            .withStatus(HttpStatus.SERVICE_UNAVAILABLE.value())));
+
+        assertThrows(FeignException.class, () -> productClient.getProduct(productId));
+    }
+
+    @Test
+    public void givenProductIdNotFound_whenGetProductCalled_thenThrowFeignException() {
+        String productId = "test";
+
+        stubFor(get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse()
+            .withStatus(HttpStatus.NOT_FOUND.value())));
+
+        assertThrows(FeignException.class, () -> productClient.getProduct(productId));
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/test/java/com/baeldung/cloud/openfeign/defaulterrorhandling/controller/ProductControllerUnitTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.controller;
+
+import com.baeldung.cloud.openfeign.defaulterrorhandling.client.ProductClient;
+import com.github.tomakehurst.wiremock.WireMockServer;
+import com.github.tomakehurst.wiremock.client.WireMock;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.cloud.openfeign.FeignAutoConfiguration;
+import org.springframework.http.HttpStatus;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+
+@RunWith(SpringRunner.class)
+@WebMvcTest(ProductController.class)
+@ImportAutoConfiguration({FeignAutoConfiguration.class, TestControllerAdvice.class})
+@EnableWebMvc
+public class ProductControllerUnitTest {
+
+    @Autowired
+    private ProductClient productClient;
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    private WireMockServer wireMockServer;
+
+    @Before
+    public void startWireMockServer() {
+        wireMockServer = new WireMockServer(8081);
+        configureFor("localhost", 8081);
+        wireMockServer.start();
+    }
+
+    @After
+    public void stopWireMockServer() {
+        wireMockServer.stop();
+    }
+
+    @Test
+    public void givenProductServiceIsnotAvailable_whenGetProductCalled_thenReturnInternalServerError() throws Exception {
+        String productId = "test";
+
+        stubFor(WireMock.get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse().withStatus(HttpStatus.SERVICE_UNAVAILABLE.value())));
+
+        mockMvc.perform(get("/myapp1/product/" + productId))
+            .andExpect(status().is(HttpStatus.INTERNAL_SERVER_ERROR.value()));
+    }
+
+
+    @Test
+    public void givenProductIsNotFound_whenGetProductCalled_thenReturnBadeRequestError() throws Exception {
+        String productId = "test";
+
+        stubFor(WireMock.get(urlEqualTo("/product/" + productId))
+            .willReturn(aResponse().withStatus(HttpStatus.NOT_FOUND.value())));
+
+        mockMvc.perform(get("/myapp1/product/" +productId))
+            .andExpect(status().is(HttpStatus.INTERNAL_SERVER_ERROR.value()));
+    }
+}

spring-cloud-modules/spring-cloud-openfeign/src/test/java/com/baeldung/cloud/openfeign/defaulterrorhandling/controller/TestControllerAdvice.java

@@ -0,0 +1,16 @@
+package com.baeldung.cloud.openfeign.defaulterrorhandling.controller;
+
+import feign.FeignException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class TestControllerAdvice {
+
+    @ExceptionHandler({FeignException.class})
+    public ResponseEntity<Object> handleFeignException(FeignException exception) {
+        return new ResponseEntity<>(exception.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+}