已棄用HttpClient？

Question

我試圖使用此follwing代碼URL下載JSON文件，

try { 
     HttpClient httpclient = new DefaultHttpClient(); 
     HttpPost httppost = new HttpPost(url); 
     HttpResponse response = httpclient.execute(httppost); 
     HttpEntity entity = response.getEntity(); 
     is = entity.getContent(); 

    } catch (Exception e) { 
     Log.e("log_tag", "Error in http connection " + e.toString()); 
    } 

不過，Android工作室表明HttpClient的，DefaultHttpClient，HttpPost是depricated。我試着用google搜索所有上面已棄用的選項，以及其他許多變化，因爲我能想到，並且找不到任何有用的結果，所以我明顯錯過了一些東西。

什麼是從URL

Answer 1

下載JSON文件。如果你不介意使用GSON

String someUrl = "http://freegeoip.net/json/"; 

URL url = new URL(someUrl); 
HttpURLConnection request = (HttpURLConnection) url.openConnection(); 
request.connect(); 

JsonParser jp = new JsonParser(); 
JsonElement root = jp.parse(new InputStreamReader((InputStream) request.getContent())); 
JsonObject rootobj = root.getAsJsonObject(); 
someProperty= rootobj.get("some_property").getAsString(); 

Answer 2

These are few workarounds; 

    1) Android 6.0 release removes support for the Apache HTTP client. If your app is using this client and targets Android 2.3 (API level 9) or higher, use the HttpURLConnection class instead. This API is more efficient because it reduces network use through transparent compression and response caching, and minimizes power consumption. 
    To continue using the Apache HTTP APIs, you must first declare the following compile-time dependency in your build.gradle file: 

    android 
    { 
     useLibrary 'org.apache.http.legacy' 
    } 

    Following is the link for your reference: 
    https://developer.android.com/about/versions/marshmallow/android-6.0-changes.html#boringSSL 
    2) If you have considerable amount of time to make changes, there are few third party open source libraries available out there such as retrofit (written by Square: https:/square.github.io/retrofit/) , volley(written by Google) which are much compact, efficient and easy to use. 
Hope this helps. Happy Coding. 

Answer 3

use this HttpClient httpClient = HttpClientBuilder.create().build(); 

，或者您可以使用

import android.util.Log; 
import org.json.JSONException; 
import org.json.JSONObject; 
import java.io.BufferedInputStream; 
import java.io.BufferedReader; 
import java.io.DataOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.UnsupportedEncodingException; 
import java.net.HttpURLConnection; 
import java.net.URL; 
import java.net.URLEncoder; 
import java.util.HashMap; 

public class JSONParser { 

    String charset = "UTF-8"; 
    HttpURLConnection conn; 
    DataOutputStream wr; 
    StringBuilder result; 
    URL urlObj; 
    JSONObject jObj = null; 
    StringBuilder sbParams; 
    String paramsString; 

    public JSONObject makeHttpRequest(String url, String method, 
             HashMap<String, String> params) { 

     sbParams = new StringBuilder(); 
     int i = 0; 
     for (String key : params.keySet()) { 
      try { 
       if (i != 0){ 
        sbParams.append("&"); 
       } 
       sbParams.append(key).append("=") 
         .append(URLEncoder.encode(params.get(key), charset)); 

      } catch (UnsupportedEncodingException e) { 
       e.printStackTrace(); 
      } 
      i++; 
     } 

     if (method.equals("POST")) { 
      // request method is POST 
      try { 
       urlObj = new URL(url); 

       conn = (HttpURLConnection) urlObj.openConnection(); 

       conn.setDoOutput(true); 

       conn.setRequestMethod("POST"); 

       conn.setRequestProperty("Accept-Charset", charset); 

       conn.setReadTimeout(10000); 
       conn.setConnectTimeout(15000); 

       conn.connect(); 

       paramsString = sbParams.toString(); 

       wr = new DataOutputStream(conn.getOutputStream()); 
       wr.writeBytes(paramsString); 
       wr.flush(); 
       wr.close(); 

      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } 
     else if(method.equals("GET")){ 
      // request method is GET 

      if (sbParams.length() != 0) { 
       url += "?" + sbParams.toString(); 
      } 

      try { 
       urlObj = new URL(url); 

       conn = (HttpURLConnection) urlObj.openConnection(); 

       conn.setDoOutput(false); 

       conn.setRequestMethod("GET"); 

       conn.setRequestProperty("Accept-Charset", charset); 

       conn.setConnectTimeout(15000); 

       conn.connect(); 

      } catch (IOException e) { 
       e.printStackTrace(); 
      } 

     } 

     try { 
      //Receive the response from the server 
      InputStream in = new BufferedInputStream(conn.getInputStream()); 
      BufferedReader reader = new BufferedReader(new InputStreamReader(in)); 
      result = new StringBuilder(); 
      String line; 
      while ((line = reader.readLine()) != null) { 
       result.append(line); 
      } 

      Log.d("JSON Parser", "result: " + result.toString()); 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 

     conn.disconnect(); 

     // try parse the string to a JSON object 
     try { 
      jObj = new JSONObject(result.toString()); 
     } catch (JSONException e) { 
      Log.e("JSON Parser", "Error parsing data " + e.toString()); 
     } 

     // return JSON Object 
     return jObj; 
    } 
}