Feign

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/AppController.java

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+package com.javadevjournal.feignclientexample;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class AppController {
+
+    @Autowired
+    ProductServiceClient productServiceClient;
+
+    @GetMapping("/fetchProducts")
+    public ResponseEntity<?> fetchProducts() {
+
+        return ResponseEntity.ok(productServiceClient.getAllProducts());
+    }
+
+    @GetMapping("/fetchProduct/{id}")
+    public ResponseEntity<?> fetchProduct(@PathVariable int id) {
+        Product product = productServiceClient.getProduct(id);
+
+        return ResponseEntity.ok(product);
+    }
+
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/FeignClientExampleApplication.java

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+package com.javadevjournal.feignclientexample;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
+import org.springframework.cloud.openfeign.EnableFeignClients;
+
+@SpringBootApplication
+@EnableDiscoveryClient
+@EnableFeignClients
+public class FeignClientExampleApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(FeignClientExampleApplication.class, args);
+    }
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/Product.java

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+package com.javadevjournal.feignclientexample;
+
+public class Product {
+
+    private Integer id;
+
+    private String name;
+
+    private double price;
+
+    public Product(Integer id, String name, double price) {
+        this.id = id;
+        this.name = name;
+        this.price = price;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/ProductServiceClient.java

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+package com.javadevjournal.feignclientexample;
+
+import java.util.List;
+
+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-service"/*, url = "http://localhost:8081"*/)
+public interface ProductServiceClient {
+
+    @RequestMapping(value = "/products", method = RequestMethod.GET)
+    public List<Product> getAllProducts();
+
+    @RequestMapping(value = "/product/{id}", method = RequestMethod.GET)
+    public Product getProduct(@PathVariable("id") int productId);
+
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/errors/AppExceptionHandler.java

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+package com.javadevjournal.feignclientexample.errors;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class AppExceptionHandler {
+
+    @ResponseBody
+    @ExceptionHandler(value = ProductNotFoundException.class)
+    public ResponseEntity<?> handleException(ProductNotFoundException exception) {
+        return ResponseEntity.status(HttpStatus.NOT_FOUND)
+            .body(exception.getMessage());
+    }
+
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/errors/AppFeignErrorDecoder.java

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+package com.javadevjournal.feignclientexample.errors;
+
+import org.springframework.stereotype.Component;
+
+import feign.Response;
+import feign.codec.ErrorDecoder;
+
+@Component
+public class AppFeignErrorDecoder implements ErrorDecoder {
+
+    private final ErrorDecoder defaultErrorDecoder = new Default();
+
+    @Override
+    public Exception decode(String methodKey, Response response) {
+        if (response.status() >= 400 && response.status() <= 499) {
+            throw new ProductNotFoundException("Product Not Found");
+        }
+
+        return defaultErrorDecoder.decode(methodKey, response);
+    }
+
+}

Spring-Boot/spring-feign/feign-client-example/src/main/java/com/javadevjournal/feignclientexample/errors/ProductNotFoundException.java

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+package com.javadevjournal.feignclientexample.errors;
+
+public class ProductNotFoundException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    public ProductNotFoundException(String msg) {
+        super(msg);
+    }
+}

Spring-Boot/spring-feign/feign-client-example/src/main/resources/application.properties

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+server.port=8080
+spring.application.name=feign-client-example

Spring-Boot/spring-feign/feign-client-example/src/test/java/com/javadevjournal/feignclient/FeignClientApplicationTests.java

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+package com.javadevjournal.feignclient;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class FeignClientApplicationTests {
+
+	@Test
+	public void contextLoads() {
+	}
+
+}