reiheAPicker/src/logic_reiheAPicker/ChatGPTApiCallerClass.java

package logic_reiheAPicker;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class ChatGPTApiCallerClass {

	public static String chatGPT(String prompt) {
		
	    String url = "https://api.openai.com/v1/chat/completions";
	    String apiKey = var_reiheAPicker.Constants.ChatGPTApiKey;
	    String model = "gpt-4o";
	    prompt = "You are assessing the relevance of books for a school-focused educational library. " +
	            "The target audience includes students and educators in all school-related disciplines (such as mathematics, science, languages, history, geography, social studies, arts, physical education, computer science, etc.). " +
	            "Your task is to rate each book's relevance using this fixed output format: " +
	            "'87; highly relevant but in English.' " +
	            "Format rules: " +
	            "- First, a number from 0 to 100 indicating the relevance. " +
	            "- Then, a short explanation in plain language. " +
	            "- Only use German or English titles. " +
	            "- German books are preferred. " +
	            "- English books are acceptable only if highly relevant. " +
	            "- Ignore books in other languages (output: '0; not in German or English.') " +
	            "Always follow this format. Don’t include anything else. " +
	            "Now evaluate the following title: " + prompt; try {
			Thread.sleep(3000);
		} catch (InterruptedException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
	    
	    HttpURLConnection connection = null;

	    try {
	        URL obj = new URL(url);
	        connection = (HttpURLConnection) obj.openConnection();
	        connection.setRequestMethod("POST");
	        connection.setRequestProperty("Authorization", "Bearer " + apiKey);
	        connection.setRequestProperty("Content-Type", "application/json");

	        // The request body
	        String body = "{\"model\": \"" + model + "\", \"messages\": [{\"role\": \"user\", \"content\": \"" + prompt + "\"}]}";

	        connection.setDoOutput(true);
	        OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
	        writer.write(body);
	        writer.flush();
	        writer.close();

	        // Response from ChatGPT
	        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
	        String line;
	        StringBuilder response = new StringBuilder();

	        while ((line = br.readLine()) != null) {
	            response.append(line);
	        }
	        br.close();

	        // Call the method to extract the message
	        return extractMessageFromJSONResponse(response.toString());

	    } catch (IOException e) {
	        // Handle errors and print the API response if available
	        if (connection != null) {
	            try {
	                InputStream errorStream = connection.getErrorStream();
	                if (errorStream != null) {
	                    BufferedReader errorReader = new BufferedReader(new InputStreamReader(errorStream));
	                    StringBuilder errorResponse = new StringBuilder();
	                    String line;
	                    while ((line = errorReader.readLine()) != null) {
	                        errorResponse.append(line);
	                    }
	                    errorReader.close();
	                    System.err.println("Error response from OpenAI API: " + errorResponse.toString());
	                    // Log and continue without throwing
	                    return "skipped due to error"; // Or handle it gracefully based on your program's needs
	                }
	            } catch (IOException ex) {
	                System.err.println("Failed to read error stream from OpenAI API");
	                ex.printStackTrace();
	                // Log and continue without throwing
	                return "skipped due to error"; // Or handle it gracefully
	            }
	        }
	        System.err.println("Error occurred while connecting to OpenAI API: " + e.getMessage());
	        e.printStackTrace();
	        // Log and continue without throwing
	        return "skipped due to error"; // Or handle it gracefully
	    }
	}

   public static String extractMessageFromJSONResponse(String response) {
       int start = response.indexOf("content")+ 11;

       int end = response.indexOf("\"", start);

       return response.substring(start, end);

   }
  
}