Add @ApiOperation vs @ApiResponse in Swagger (#12570)

* Add @ApiOperation vs @ApiResponse in Swagger

* Minor fixes

* Fix - rename package

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/SwaggerDemoApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.swaggerresponses;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SwaggerDemoApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SwaggerDemoApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/config/SwaggerConfiguration.java

@@ -0,0 +1,23 @@
+package com.baeldung.swaggerresponses.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import springfox.documentation.builders.PathSelectors;
+import springfox.documentation.builders.RequestHandlerSelectors;
+import springfox.documentation.spi.DocumentationType;
+import springfox.documentation.spring.web.plugins.Docket;
+
+@Configuration
+public class SwaggerConfiguration {
+
+    @Bean
+    public Docket api() {
+        return new Docket(DocumentationType.SWAGGER_2).select()
+            .apis(RequestHandlerSelectors.any())
+            .paths(PathSelectors.any())
+            .build();
+    }
+
+}
+

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/controller/CustomerController.java

@@ -0,0 +1,38 @@
+package com.baeldung.swaggerresponses.controller;
+
+import com.baeldung.swaggerresponses.response.CustomerResponse;
+import com.baeldung.swaggerresponses.response.ErrorResponse;
+import com.baeldung.swaggerresponses.service.CustomerService;
+
+import io.swagger.annotations.Api;
+import io.swagger.annotations.ApiOperation;
+import io.swagger.annotations.ApiResponse;
+import io.swagger.annotations.ApiResponses;
+
+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.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@Api("Customer Controller")
+@RestController
+@RequestMapping("/customers")
+public class CustomerController {
+
+    private final CustomerService customerService;
+
+    public CustomerController(CustomerService customerService) {
+        this.customerService = customerService;
+    }
+
+    @ApiOperation(value = "Gets customer by ID", response = CustomerResponse.class, notes = "Customer must exist")
+    @ApiResponses(value = {
+        @ApiResponse(code = 400, message = "Invalid ID supplied"),
+        @ApiResponse(code = 404, message = "Customer not found"),
+        @ApiResponse(code = 500, message = "Internal server error", response = ErrorResponse.class) })
+    @GetMapping("/{id}")
+    public ResponseEntity<CustomerResponse> getCustomer(@PathVariable("id") Long id) {
+        return ResponseEntity.ok(customerService.getById(id));
+    }
+}

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/response/CustomerResponse.java

@@ -0,0 +1,27 @@
+package com.baeldung.swaggerresponses.response;
+
+public class CustomerResponse {
+
+    private final Long id;
+    private final String firstName;
+    private final String lastName;
+
+    public CustomerResponse(Long id, String firstName, String lastName) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+}

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/response/ErrorResponse.java

@@ -0,0 +1,23 @@
+package com.baeldung.swaggerresponses.response;
+
+public class ErrorResponse {
+
+    private String error;
+    private String message;
+
+    public String getError() {
+        return error;
+    }
+
+    public void setError(String error) {
+        this.error = error;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+}

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/service/CustomerService.java

@@ -0,0 +1,8 @@
+package com.baeldung.swaggerresponses.service;
+
+import com.baeldung.swaggerresponses.response.CustomerResponse;
+
+public interface CustomerService {
+
+    CustomerResponse getById(Long id);
+}

spring-boot-modules/spring-boot-swagger/src/main/java/com/baeldung/swaggerresponses/service/DefaultCustomerService.java

@@ -0,0 +1,13 @@
+package com.baeldung.swaggerresponses.service;
+
+import com.baeldung.swaggerresponses.response.CustomerResponse;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class DefaultCustomerService implements CustomerService {
+    @Override
+    public CustomerResponse getById(Long id) {
+        return new CustomerResponse(1L, "Jane", "Doe");
+    }
+}