Java 获取 URL 响应头

    import java.io.IOException;
    import java.net.URL;
    import java.net.URLConnection;
    import java.util.Map;
    import java.util.Set;
     
    public class Main {
    public static void main(String[] args) throws IOException{
        URL url = new URL("http://www.baidu.com");
        URLConnection conn = url.openConnection();
        
        Map headers = conn.getHeaderFields();
        Set<String> keys = headers.keySet();
        for( String key : keys ){
            String val = conn.getHeaderField(key);
            System.out.println(key