AiServiceBeanOutputConverter.java

package com.example.demo.service;

import java.util.HashMap;
import java.util.Map;

import org.springframework.ai.chat.client.ChatClient;
import org.springframework.ai.chat.prompt.Prompt;
import org.springframework.ai.chat.prompt.PromptTemplate;
import org.springframework.ai.converter.BeanOutputConverter;
import org.springframework.ai.openai.OpenAiChatOptions;
import org.springframework.ai.openai.api.ResponseFormat;
import org.springframework.stereotype.Service;

import com.example.demo.dto.Hotel;

import lombok.extern.slf4j.Slf4j;

@Service
@Slf4j
public class AiServiceBeanOutputConverter {
  // ##### 필드 #####
  private ChatClient chatClient;

  // ##### 생성자 #####
  public AiServiceBeanOutputConverter(ChatClient.Builder chatClientBuilder) {
    chatClient = chatClientBuilder.build();
  }

  // ##### 메소드 #####
  public Hotel beanOutputConverterLowLevel(String city) {
    // 구조화된 출력 변환기 생성
    BeanOutputConverter<Hotel> beanOutputConverter = new BeanOutputConverter<>(Hotel.class);
    // 프롬프트 템플릿 생성
    PromptTemplate promptTemplate = PromptTemplate.builder()
        .template("{city}에서 유명한 호텔 목록 5개를 출력하세요. {format}")
        .build();
    // 프롬프트 생성
    Prompt prompt = promptTemplate.create(Map.of(
        "city", city,
        "format", beanOutputConverter.getFormat()));
    // LLM의 JSON 출력 얻기
    String json = chatClient.prompt(prompt)
        .call()
        .content();
    // JSON을 Hotel로 매핑해서 변환
    Hotel hotel = beanOutputConverter.convert(json);
    return hotel;
  }
public Hotel LowLevel(){
    ResponseFormat.JsonSchema jsonSchema = ResponseFormat.JsonSchema.builder()
        .name("hotel")
        .schema("""
            {
                "name":"hotel",
                "strict":"true",
                "schema":{
                    "type":"object",
                    "properties":{
                        "city":{"type":"string"},
                        "names":{"type":"array", "items":{"type":"string"}}
                    }
                },
                "required":["city", "names"]
            }
        """)
        .strict(true)
        .build();

    ResponseFormat responseFormat = ResponseFormat.builder()
        .type(ResponseFormat.Type.JSON_SCHEMA)
        .jsonSchema(jsonSchema)
        .build();
    OpenAiChatOptions options = OpenAiChatOptions.builder()
        .model("gpt-4o-mini")
        .responseFormat(responseFormat)
        .build();
    BeanOutputConverter<Hotel> beanOutputConverter = new BeanOutputConverter<>(Hotel.class);
    Prompt prompt = new Prompt("서울에서 유명한 호텔 목록 5개를 출력하세요.", options);
    String json = chatClient.prompt(prompt)
        .call()
        .content();
    Hotel hotel = beanOutputConverter.convert(json);
    return hotel;
}
  public Hotel beanOutputConverterHighLevel(String city) {
    Hotel hotel = chatClient.prompt()
        .user("%s에서 유명한 호텔 목록 5개를 출력하세요.".formatted(city))
        .call()
        .entity(Hotel.class);
    return hotel;
  }  
}