模拟的rest模板交换方法返回空

import org.springframework.web.client.RestTemplate;
import org.springframework.http.ResponseEntity;
import org.springframework.http.HttpStatus;

public class RestTemplateExample {
    public static void main(String[] args) {
        RestTemplate restTemplate = new RestTemplate();
        String url = "http://example.com/api/resource";

        try {
            ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
            
            if (response.getStatusCode() == HttpStatus.OK) {
                String result = response.getBody();
                if (result != null && !result.isEmpty()) {
                    System.out.println("Response: " + result);
                } else {
                    System.out.println("Received an empty response.");
                }
            } else {
                System.out.println("Failed to get data. Status code: " + response.getStatusCode());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}