如何在java中获取响应代码

我希望我的程序中有响应代码 请告诉我以下代码中的错误是什么

  public class Main{
      public static void main(String args[]) throws Exception {
        URL url = new URL("http://www.google.com");
        HttpURLConnection httpCon = openConnection();


        System.out.println("Response code is " + httpCon.getResponseCode());
     }
    }

---

问题的原因是编译器告诉类构造函数（URL）和方法（

openConnection

）抛出异常（在它们的

签名中定义）并采取一些必要的步骤

您有两种选择：

Throw
检查的异常来自主方法

public static void main(String[] args) throws IOException {
            URL url = new URL("http://www.google.com");
            HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
                System.out.println("Response code is " +
                                              httpCon.getResponseCode());
             }

或

使用
try catch block捕获
异常
。

public static void main(String[] args) {
        URL url;
        HttpURLConnection httpCon;
        try {
            url = new URL("http://www.google.com");
            httpCon = (HttpURLConnection) url.openConnection();
            System.out.println("Response code is " + httpCon.getResponseCode());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

你忘了放
url
将其更改为
HttpURLConnection httpCon=（HttpURLConnection）url.openConnection（）

尝试将对象强制转换为HttpURLConnection

public class Main{
  public static void main(String args[]) throws Exception {
    URL url = new URL("http://www.google.com");
    //Cast the object to  HttpURLConnection
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
    System.out.println("Response code is " + httpCon.getResponseCode());
 }
}

错误是显而易见的

openConnection（）
是
URL
类的方法，未在类中定义。必须使用前面创建的URL类的对象

对openConnection（）方法的调用必须如下所示-

url.openConnection（）
它返回一个
URLConnection
对象。您必须将此对象键入
HttpURLConnection
您看到了什么错误？openConnection（）；你是说url.openConnection（）？？请告诉我们堆栈跟踪/错误以及
openConnection（）
的代码，我想OP的意思是
url.openConnection（）
。他们定义一个局部变量，然后调用一个没有参数的方法。
package naveed.workingfiles;

import java.net.HttpURLConnection;
import java.net.URL;

public class Url {

    public static void main(String args[]) throws Exception {
        URL url = new URL("http://www.google.com");
        HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();

        System.out.println("Response code is " + httpCon.getResponseCode());
    }
}

public class Main{
  public static void main(String args[]) throws Exception {
    URL url = new URL("http://www.google.com");
    //Cast the object to  HttpURLConnection
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
    System.out.println("Response code is " + httpCon.getResponseCode());
 }
}