我试图做POST与HttpURLConnection(我需要使用这种方式,不能使用HttpPost),我想添加参数的连接,如

post.setEntity(new UrlEncodedFormEntity(nvp));

在哪里

nvp = new ArrayList<NameValuePair>();

有一些数据存储在。我找不到一种方法如何添加这个数组列表到我的HttpURLConnection在这里:

HttpsURLConnection https = (HttpsURLConnection) url.openConnection();
https.setHostnameVerifier(DO_NOT_VERIFY);
http = https;
http.setRequestMethod("POST");
http.setDoInput(true);
http.setDoOutput(true);

出现这种尴尬的https和http组合的原因是不需要验证证书。不过,这不是问题,它可以很好地发布服务器。但我需要它来张贴论点。

什么好主意吗?


重复的免责声明:

早在2012年,我还不知道如何在HTTP POST请求中插入参数。我一直在使用NameValuePair,因为它在教程中。这个问题可能看起来像一个重复的问题,然而,我2012年自己读了另一个问题,它没有使用NameValuePair。事实上,这并没有解决我的问题。


当前回答

参数到HttpURLConnection使用POST使用NameValuePair输出

        try {
        URL url = new URL("https://yourUrl.com");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        conn.setUseCaches(false);
        conn.setDoInput(true);
        conn.setDoOutput(true);

        conn.setRequestMethod("POST");

        conn.setRequestProperty("Content-Type", "application/json");

        JSONObject data = new JSONObject();
        data.put("key1", "value1");
        data.put("key2", "value2");

        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        wr.write(data.toString());
        wr.flush();
        wr.close();

        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        System.out.println(response.toString());
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        e.printStackTrace();
    }

其他回答

一个解决方案是让你自己的params字符串。

这是我在我的最新项目中使用的实际方法。你需要将args从hashtable更改为namevaluepair:

private static String getPostParamString(Hashtable<String, String> params) {
    if(params.size() == 0)
        return "";

    StringBuffer buf = new StringBuffer();
    Enumeration<String> keys = params.keys();
    while(keys.hasMoreElements()) {
        buf.append(buf.length() == 0 ? "" : "&");
        String key = keys.nextElement();
        buf.append(key).append("=").append(params.get(key));
    }
    return buf.toString();
}

发布参数:

OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(getPostParamString(req.getPostParams()));

使用PrintWriter有一个更简单的方法(见这里)

基本上你所需要的是:

// set up URL connection
URL urlToRequest = new URL(urlStr);
HttpURLConnection urlConnection = (HttpURLConnection)urlToRequest.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

// write out form parameters
String postParamaters = "param1=value1&param2=value2"
urlConnection.setFixedLengthStreamingMode(postParameters.getBytes().length);
PrintWriter out = new PrintWriter(urlConnection.getOutputStream());
out.print(postParameters);
out.close();

// connect
urlConnection.connect();

试试这个:

HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("your url");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(3);
nameValuePairs.add(new BasicNameValuePair("user_name", "Name"));
nameValuePairs.add(new BasicNameValuePair("pass","Password" ));
nameValuePairs.add(new BasicNameValuePair("user_email","email" ));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);

String ret = EntityUtils.toString(response.getEntity());
Log.v("Util response", ret);

您可以根据需要添加任意数量的nameValuePairs。别忘了在名单上提到人数。

如果还来得及的话,我想分享一下我的代码

Utils.java:

public static String buildPostParameters(Object content) {
        String output = null;
        if ((content instanceof String) ||
                (content instanceof JSONObject) ||
                (content instanceof JSONArray)) {
            output = content.toString();
        } else if (content instanceof Map) {
            Uri.Builder builder = new Uri.Builder();
            HashMap hashMap = (HashMap) content;
            if (hashMap != null) {
                Iterator entries = hashMap.entrySet().iterator();
                while (entries.hasNext()) {
                    Map.Entry entry = (Map.Entry) entries.next();
                    builder.appendQueryParameter(entry.getKey().toString(), entry.getValue().toString());
                    entries.remove(); // avoids a ConcurrentModificationException
                }
                output = builder.build().getEncodedQuery();
            }
        }

        return output;
    }

public static URLConnection makeRequest(String method, String apiAddress, String accessToken, String mimeType, String requestBody) throws IOException {
        URL url = new URL(apiAddress);
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

        urlConnection.setDoInput(true);
        urlConnection.setDoOutput(!method.equals("GET"));
        urlConnection.setRequestMethod(method);

        urlConnection.setRequestProperty("Authorization", "Bearer " + accessToken);        

        urlConnection.setRequestProperty("Content-Type", mimeType);
        OutputStream outputStream = new BufferedOutputStream(urlConnection.getOutputStream());
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "utf-8"));
        writer.write(requestBody);
        writer.flush();
        writer.close();
        outputStream.close();            

        urlConnection.connect();

        return urlConnection;
    }

MainActivity.java:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    new APIRequest().execute();
}

private class APIRequest extends AsyncTask<Void, Void, String> {

        @Override
        protected Object doInBackground(Void... params) {

            // Of course, you should comment the other CASES when testing one CASE

            // CASE 1: For FromBody parameter
            String url = "http://10.0.2.2/api/frombody";
            String requestBody = Utils.buildPostParameters("'FromBody Value'"); // must have '' for FromBody parameter
            HttpURLConnection urlConnection = null;
            try {
                urlConnection = (HttpURLConnection) Utils.makeRequest("POST", url, null, "application/json", requestBody);                    
                InputStream inputStream;
                // get stream
                if (urlConnection.getResponseCode() < HttpURLConnection.HTTP_BAD_REQUEST) {
                    inputStream = urlConnection.getInputStream();
                } else {
                    inputStream = urlConnection.getErrorStream();
                }
                // parse stream
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                String temp, response = "";
                while ((temp = bufferedReader.readLine()) != null) {
                    response += temp;
                }
                return response;
            } catch (IOException e) {
                e.printStackTrace();
                return e.toString();
            } finally {
                if (urlConnection != null) {
                    urlConnection.disconnect();
                }
            }

            // CASE 2: For JSONObject parameter
            String url = "http://10.0.2.2/api/testjsonobject";
            JSONObject jsonBody;
            String requestBody;
            HttpURLConnection urlConnection;
            try {
                jsonBody = new JSONObject();
                jsonBody.put("Title", "BNK Title");
                jsonBody.put("Author", "BNK");
                jsonBody.put("Date", "2015/08/08");
                requestBody = Utils.buildPostParameters(jsonBody);
                urlConnection = (HttpURLConnection) Utils.makeRequest("POST", url, null, "application/json", requestBody);                    
                ...
                // the same logic to case #1
                ...
                return response;
            } catch (JSONException | IOException e) {
                e.printStackTrace();
                return e.toString();
            } finally {
                if (urlConnection != null) {
                    urlConnection.disconnect();
                }
            }           

            // CASE 3: For form-urlencoded parameter
            String url = "http://10.0.2.2/api/token";
            HttpURLConnection urlConnection;
            Map<String, String> stringMap = new HashMap<>();
            stringMap.put("grant_type", "password");
            stringMap.put("username", "username");
            stringMap.put("password", "password");
            String requestBody = Utils.buildPostParameters(stringMap);
            try {
                urlConnection = (HttpURLConnection) Utils.makeRequest("POST", url, null, "application/x-www-form-urlencoded", requestBody);
                ...
                // the same logic to case #1
                ...
                return response;
            } catch (Exception e) {
                e.printStackTrace();
                return e.toString();
            } finally {
                if (urlConnection != null) {
                    urlConnection.disconnect();
                }
            }                  
        }

        @Override
        protected void onPostExecute(String response) {
            super.onPostExecute(response);
            // do something...
        }
    }

接受的回答在以下位置抛出ProtocolException:

OutputStream os = conn.getOutputStream();

因为它没有为URLConnection对象启用输出。解决方案应该包括:

conn.setDoOutput(真正的);

让它起作用。