在Java中使用JSON从API获得邮政编码数据

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

public class PostalCodeFetcher {
    public static void main(String[] args) {
        String apiUrl = "https://api.example.com/postal-codes?city=example";
        
        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpGet httpGet = new HttpGet(apiUrl);
        
        try {
            HttpResponse response = httpClient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            
            if (entity != null) {
                String responseBody = EntityUtils.toString(entity);
                
                // 使用Jackson库解析JSON数据
                ObjectMapper objectMapper = new ObjectMapper();
                JsonNode jsonNode = objectMapper.readTree(responseBody);
                
                // 提取邮政编码数据
                JsonNode postalCodeNode = jsonNode.get("postalCode");
                String postalCode = postalCodeNode.asText();
                
                System.out.println("Postal Code: " + postalCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}