Langchain4j-05

注意：为了提高 LLM 调用正确工具并传递正确参数的机会，我们应该提供清晰且明确的：
- 工具名称
- 工具的功能描述以及何时应该使用它
- 每个工具参数的描述
一条好的经验法则：如果人类能够理解一个工具的用途以及如何使用它，那么 LLM 很可能也能。

//方法1
ToolSpecification toolSpecification = ToolSpecification.builder()
    .name("getWeather")
    .description("Returns the weather forecast for a given city")
    .parameters(JsonObjectSchema.builder()
        .addStringProperty("city", "The city for which the weather forecast should be returned")
        .addEnumProperty("temperatureUnit", List.of("CELSIUS", "FAHRENHEIT"))
        .required("city") // the required properties should be specified explicitly
        .build())
    .build();

//方法2
class WeatherTools { 
  
    @Tool("Returns the weather forecast for a given city")
    String getWeather(
            @P("The city for which the weather forecast should be returned") String city,
            TemperatureUnit temperatureUnit
    ) {
        ...
    }
}

List<ToolSpecification> toolSpecifications = ToolSpecifications.toolSpecificationsFrom(WeatherTools.class);

ChatRequest request = ChatRequest.builder()
    .messages(UserMessage.from("What will the weather be like in London tomorrow?"))
    .toolSpecifications(toolSpecifications)
    .build();
ChatResponse response = model.chat(request);
AiMessage aiMessage = response.aiMessage();

String result = "It is expected to rain in London tomorrow.";
ToolExecutionResultMessage toolExecutionResultMessage = ToolExecutionResultMessage.from(toolExecutionRequest, result);
ChatRequest request2 = ChatRequest.builder()
        .messages(List.of(userMessage, aiMessage, toolExecutionResultMessage))
        .toolSpecifications(toolSpecifications)
        .build();
ChatResponse response2 = model.chat(request2);

  
import dev.langchain4j.agent.tool.Tool;  
import dev.langchain4j.memory.chat.MessageWindowChatMemory;  
import dev.langchain4j.model.chat.ChatModel;  
import dev.langchain4j.service.AiServices;  
import dev.langchain4j.service.spring.AiService;  
import jakarta.annotation.Resource;  
import lombok.extern.slf4j.Slf4j;  
import org.springframework.stereotype.Service;  
  
@Service  
@Slf4j  
public class ServiceWithToolsExample {  
  
    @Resource  
    private ChatModel qwenChatModel;  
    
    static class Calculator {  
        @Tool("Calculates the length of a string")  
        int stringLength(String s) {  
            System.out.println("Called stringLength with s='" + s + "'");  
            return s.length();  
        }  
        @Tool("Calculates the sum of two numbers")  
        int add(int a, int b) {  
            System.out.println("Called add with a=" + a + ", b=" + b);  
            return a + b;  
        }  
        @Tool("Calculates the square root of a number")  
        double sqrt(int x) {  
            System.out.println("Called sqrt with x=" + x);  
            return Math.sqrt(x);  
        }  
    }  
  
    @AiService  
    interface Assistant {  
        String chat(String userMessage);  
    }  
  
    public  void test() {  
        Assistant assistant = AiServices.builder(Assistant.class)  
                .chatModel(qwenChatModel)  
                .tools(new Calculator())  
                .chatMemory(MessageWindowChatMemory.withMaxMessages(10))  
                .build();  
        String question = "What is the square root of the sum of the numbers of letters in the words \"hello\" and \"world\"?";  
        String answer = assistant.chat(question);  
        System.out.println(answer);  
      
    }  
}