BAEL-6355 - OpenAI API with Spring Boot

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/openapi/config/OpenAIRestTemplateConfig.java

@@ -0,0 +1,25 @@
+package com.baeldung.openapi.config;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestTemplate;
+
+@Configuration
+public class OpenAIRestTemplateConfig {
+
+    @Value("${openai.api.key}")
+    private String openaiApiKey;
+
+    @Bean
+    @Qualifier("openaiRestTemplate")
+    public RestTemplate openaiRestTemplate() {
+        RestTemplate restTemplate = new RestTemplate();
+        restTemplate.getInterceptors().add((request, body, execution) -> {
+            request.getHeaders().add("Authorization", "Bearer " + openaiApiKey);
+            return execution.execute(request, body);
+        });
+        return restTemplate;
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/openapi/controller/ChatController.java

@@ -0,0 +1,44 @@
+package com.baeldung.openapi.controller;
+
+import com.baeldung.openapi.dto.ChatRequest;
+import com.baeldung.openapi.dto.ChatResponse;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+
+@RestController
+public class ChatController {
+
+    @Qualifier("openaiRestTemplate")
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @Value("${openai.model}")
+    private String model;
+
+    @Value("${openai.api.url}")
+    private String apiUrl;
+
+    @GetMapping("/chat")
+    public String chat(@RequestParam String prompt) {
+        // create a request
+        ChatRequest request = new ChatRequest(model, prompt);
+
+        // call the API
+        ChatResponse response = restTemplate.postForObject(
+                apiUrl,
+                request,
+                ChatResponse.class);
+
+        if (response == null || response.getChoices() == null || response.getChoices().isEmpty()) {
+            return "No response";
+        }
+
+        // return the first response
+        return response.getChoices().get(0).getMessage().getContent();
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/openapi/dto/ChatRequest.java

@@ -0,0 +1,32 @@
+package com.baeldung.openapi.dto;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ChatRequest {
+    private String model;
+    private List<Message> messages;
+
+    public ChatRequest(String model, String prompt) {
+        this.model = model;
+
+        this.messages = new ArrayList<>();
+        this.messages.add(new Message("user", prompt));
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public List<Message> getMessages() {
+        return messages;
+    }
+
+    public void setMessages(List<Message> messages) {
+        this.messages = messages;
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/openapi/dto/ChatResponse.java

@@ -0,0 +1,38 @@
+package com.baeldung.openapi.dto;
+
+import java.util.List;
+
+public class ChatResponse {
+
+    private List<Choice> choices;
+
+    public static class Choice {
+
+        private int index;
+        private Message message;
+
+        public int getIndex() {
+            return index;
+        }
+
+        public void setIndex(int index) {
+            this.index = index;
+        }
+
+        public Message getMessage() {
+            return message;
+        }
+
+        public void setMessage(Message message) {
+            this.message = message;
+        }
+    }
+
+    public List<Choice> getChoices() {
+        return choices;
+    }
+
+    public void setChoices(List<Choice> choices) {
+        this.choices = choices;
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/openapi/dto/Message.java

@@ -0,0 +1,31 @@
+package com.baeldung.openapi.dto;
+
+public class Message {
+
+    private String role;
+    private String content;
+
+    Message(String role, String content) {
+        this.role = role;
+        this.content = content;
+    }
+
+    Message() {
+    }
+
+    public String getRole() {
+        return role;
+    }
+
+    public void setRole(String role) {
+        this.role = role;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/resources/application.properties

@@ -47,4 +47,8 @@ resilience4j.ratelimiter.instances.rateLimiterApi.limit-refresh-period=60s
 resilience4j.ratelimiter.instances.rateLimiterApi.timeout-duration=0s
 resilience4j.ratelimiter.instances.rateLimiterApi.allow-health-indicator-to-fail=true
 resilience4j.ratelimiter.instances.rateLimiterApi.subscribe-for-events=true
-resilience4j.ratelimiter.instances.rateLimiterApi.event-consumer-buffer-size=50
+resilience4j.ratelimiter.instances.rateLimiterApi.event-consumer-buffer-size=50
+
+openai.model=gpt-3.5-turbo
+openai.api.url=https://api.openai.com/v1/chat/completions
+openai.api.key=your-api-key