使用httpclient有一种方法来获取具有HEAD请求的页面的字符集吗？

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpHead;
import org.apache.http.impl.client.HttpClientBuilder;

public class HttpClientExample {
    public static void main(String[] args) {
        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpHead httpHead = new HttpHead("http://example.com");
        
        try {
            HttpResponse response = httpClient.execute(httpHead);
            String contentType = response.getFirstHeader("Content-Type").getValue();
            String charset = getCharsetFromContentType(contentType);
            
            System.out.println("Charset: " + charset);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    private static String getCharsetFromContentType(String contentType) {
        String charset = "UTF-8"; // 默认字符集为UTF-8
        
        if (contentType != null) {
            String[] values = contentType.split(";");

            for (String value : values) {
                value = value.trim();

                if (value.toLowerCase().startsWith("charset=")) {
                    charset = value.substring("charset=".length());
                    break;
                }
            }
        }
        
        return charset;
    }
}