如何减少java中的冗余编码？

Question

public static byte[] sendRequest(String url ,Object params ,boolean isHttps){
        if(isHttps){
            HttpsURLConnection urlConnection = (HttpsURLConnection)newURL(url).openConnection();
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.setRequestMethod("POST");
            urlConnection.setConnectTimeout(5000);
            urlConnection.setReadTimeout(60000);
            urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
       }

        }else{
            HttpURLConnection urlConnection = (HttpURLConnection)new URL(url).openConnection();
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.setRequestMethod("POST");
            urlConnection.setConnectTimeout(5000);
            urlConnection.setReadTimeout(60000);
            urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");

        }


}

在这里，if和else在类型转换旁边都包含相同的代码行。如果我再次将这几行代码移到一个公共方法中，我希望键入cast并再次执行此过程。我怎样才能减少这些多余的线条谁能帮我。在

我在python中有一个解决方案。在

^{pr2}$

因为在python变量中，if也可以从外部块访问。在java中，我如何做到这一点。在

Answer 1

简单

public static byte[] sendRequest(String url ,Object params ,boolean isHttps){
     HttpsURLConnection urlConnection;
     if(isHttps){
         urlConnection = (HttpsURLConnection)newURL(url).openConnection();
      }else{
         urlConnection = (HttpURLConnection)new URL(url).openConnection();
      }
         urlConnection.setDoOutput(true);
         urlConnection.setDoInput(true);
         urlConnection.setRequestMethod("POST");
         urlConnection.setConnectTimeout(5000);
         urlConnection.setReadTimeout(60000);
         urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
}

Answer 2

为什么不：

HttpsURLConnection urlConnection = isHttps
                                 ? (HttpsURLConnection)newURL(url).openConnection()
                                 : (HttpsURLConnection)new URL(url).openConnection();

urlConnection.setDoOutput(true);
// etc.

与“在if之前声明变量”方法相比，这种方法的优势在于，即使变量是final，这种方法也可以工作。在

Answer 3

我假设isHttps变量检查是有原因的（？）因此，第二个cast实际上应该是HttpURLConnection，这意味着问题中有一个打字错误？ 如果是这样的话，问题中使用的大多数方法都可以在父类URLConnection中使用，而不是全部。在

幸运的是，HttpsURLConnection是HttpUrlConnection的一个子类，因此只需始终强制转换为该类即可，将其替换为（无需进行isHttps检查）：

HttpURLConnection urlConnection = (HttpURLConnection)new URL(url).openConnection();
urlConnection.setDoOutput(true);
urlConnection.setDoInput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setConnectTimeout(5000);
urlConnection.setReadTimeout(60000);
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");